description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
|---|---|---|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the priority to U.S. patent application Ser. No. 11/485,514 filed on Jul. 12, 2006, which claims the benefit of U.S. Provisional Patent Application Ser. No. 60/738,482, filed Nov. 21, 2005, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is related to sueded fabrics that are knitted with needles having at least one abrasive surface.
2. Description of Related Art
In the textile industry, it is known to finish certain woven, weft knitted, and warp knitted fabrics by abrading one or both surfaces of the fabric. The knitted fabric is abraded using sandpaper or a similarly abrasive material to cut and raise the constituent surface of the yarns knitted in the fabric into a closely raised nap, producing a soft, smooth surface texture resembling suede leather. This operation is commonly referred to as sueding, sanding, brushing, emerising, or napping (hereinafter “sueding” or “sueded”).
Sueding is conventionally performed by a specialized fabric machine that passes a knitted fabric over one or more finishing rolls, normally after the fabric has been dyed. The finishing rolls are covered with abrasive material and are rotated rapidly against the surface of the fabric. Unfortunately, conventional sueding operations have several significant disadvantages.
For example, conventional sueding processes require the knitted fabric to undergo one or more separate sueding processes after the knitting process, which can increase the cost of the resultant fabric.
In addition, conventional sueding machines necessarily cause a substantial amount of fibrous lint and fly, abrasive dust, and the like to be released from the fabric and the abrasive rolls (hereinafter “debris”). The debris can become airborne, posing a health hazard to machine operators. In addition, the debris may become embedded in the interstices of the fabric, detracting from its surface finish. Still other of the debris may accumulate on the abrasive surface of the finishing rolls, tending to negate at least somewhat their abrasive sueding effect.
Further, conventional sueding machines are typically limited in their operational widths to the processing of fabrics no greater on average than 60 to 65 inches in width. On the other hand, many conventional weaving and warp knitting machines are available for producing fabrics in widths two to three times or more greater in width than the effective operating width of conventional sueding equipment. Thus, when it is desired to produce a suede finish on fabrics of such greater widths than the maximum widthwise finishing capability of sueding machines, it is necessary to initially cut the fabric lengthwise into a least two smaller width lengths which are then individually processed through a sueding machine. Subsequently, the cut fabric must then be rejoined.
Still further, conventional sueding machines can produce streaks within the resultant fabric. These are relatively lighter or darker lines that appear in the warp direction. While these may be due to fabric or yarn irregularities, they may also occur due to random variation in the grit particles on the sueding machine. If a particularly large or aggressive particle is present in a particular location on the sueding machine, more fibers will be cut in that area such that lighter colored fibers in the yarn core may be exposed in that area, producing a streak. One method of mollifying the effect of individual grit particles to make the abrasive drum very large so that the effect of a single grit particle is not continuous. However, this method reduces the pressure of the fabric against the treatment roll, requiring either relatively coarse grit, or some other means to create pressure, such as through the utilization of flaps, backup rolls, or air pressure. Another method to make the streak more difficult to observe is to oscillate the treatment rolls along the rotational axis, which creates a sinusoidal pattern on the fabric, so that the effect of single grit particles is spread out. Oscillation is often used in multi-roll treatment machines, with the oscillations timed so as not to be superimposed. All of these processes require specialized equipment that tends to further increase the cost of the resultant fabric.
Another common problem with conventional sueding processes is that the cutting of fibers reduces the tensile properties of the fabric, regardless of yarn type.
In addition, since the sueding is conventionally performed after the fabric has been dyed there is also typically a shade change from the dyed product to the sueded one, which can be difficult to control.
Accordingly, there is a need for sueded fabrics and methods of knitting such fabrics that overcome and/or mitigate one or more of the aforementioned deleterious effects of the prior art.
BRIEF SUMMARY OF THE INVENTION
It is another object to provide a method of knitting a sueded fabric that includes using a knitting needle having an abrasive surface and moving a yarn across the abrasive surface while knitting the fabric.
It is yet another object to provide a sueded knitted fabric that includes sueded yarns throughout the body of the fabric.
These and other objects and advantages of the present invention are provided by a method of knitting a sueded fabric that includes forming an abrasive surface on a knitting needle, moving said knitting needle through a knitting cycle, and moving a yarn across said abrasive surface to form fibrils on said yarn as said knitting needle is moving through said knitting cycle.
Still other objects and advantages of the present invention are provided by a suede knitted fabric having a technical face, a technical back, and a knitted body. The technical face, technical back, and knitted body each include sueded yarns.
The above-described and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description, drawings, and appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a side view of an exemplary embodiment of a knitting needle according to the present disclosure shown in a casting off position of the knitting cycle;
FIG. 2 is a block diagram of a method of knitting a sueded fabric according to an exemplary embodiment of the present disclosure;
FIG. 3 is a top perspective view of a suede knitted fabric according to an exemplary embodiment of the present disclosure;
FIG. 4 is a side view of the knitting needle of FIG. 1 , shown in a rest or ground position of the knitting cycle;
FIG. 5 is a side view of the knitting needle of FIG. 1 , shown in a tuck height position of the knitting cycle;
FIG. 6 is a side view of the knitting needle of FIG. 1 , shown in a clearing height position of the knitting cycle;
FIG. 7 is a side view of the knitting needle of FIG. 1 , shown in a yarn feeding position of the knitting cycle;
FIG. 8 is a side view of the knitting needle of FIG. 1 , shown in a cast off position of the knitting cycle;
FIG. 9 is a side view of the knitting needle of FIG. 1 , shown in a knock over position of the knitting cycle; and
FIG. 10 is a side view of the knitting needle of FIG. 1 illustrating one or more regions of the needle having an abrasive surface.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings and in particular to FIG. 1 , a knitting needle according to the present disclosure is generally illustrated by reference numeral 10 . Advantageously, needle 10 includes at least one abrasive surface 12 defined thereon for abrading a yarn 14 during the knitting process. In this manner, needle 10 can be used to knit sueded fabrics.
Needle 10 includes a shank 16 , hook 18 , and a latch 20 . Abrasive surface 12 can be formed on the shank 16 , hook 18 , latch 20 , or combinations thereof.
In the embodiment illustrated in FIG. 1 , abrasive surface 12 is defined on shank 16 at least at a front region 22 of the shank. Front region 22 is the side of needle 10 proximate the open side of hook 18 . It is also contemplated by the present disclosure for abrasive surface 12 to be defined circumferentially about shank 16 .
Abrasive surface 12 has a predetermined surface roughness. In one embodiment, abrasive surface 12 can be formed by knurling, scuffing, or otherwise roughing the surface finish of shank 16 in region 22 . In another embodiment, abrasive surface 12 can be formed by applying an abrasive coating or paint to region 22 of shank 16 . In still another embodiment, abrasive surface 12 can be formed by applying an abrasive element such as, but not limited to, a layer of emery paper (not shown) to region 22 of shank 16 . Thus, abrasive surface 12 can be integral to and/or attached to shank 16 .
The predetermined surface roughness abrasive surface 12 is dependent upon, at least in part, the desired hand feel in the resulting fabric and the composition of yarn 14 . Preferably, the predetermined surface roughness abrasive surface 12 is sufficient to only mildly suede yarn 14 . Specifically, the predetermined surface roughness of abrasive surface 12 is sufficient to form fibrils 32 at the surface of yarn 14 , without cutting through the yarn.
As will be described in detail below, during a loop casting off portion of the knitting operation, needle 10 is moved in a first direction 26 so that yarn 14 is pulled across region 22 to cast off a knitted loop 30 . As needle 10 is used to form knitted loop 30 , yarn 14 is in contact with abrasive surface 12 while the needle is moving in the first direction 26 and the loop is pulled in a second direction 28 . It has been found that the movement of needle 10 and loop 30 in first and second directions 26 , 28 , respectively, while yarn 14 is in contact with abrasive surface 12 suedes the yarn during the formation of the knitted loop 30 to form fibrils 32 at the surface of the yarn.
Accordingly, needle 10 having abrasive surface 12 at region 22 allows knitted loop 30 to be sueded directly on the knitting machine during the casting off of the knitted loop from the needle. Yarns 14 may initially, i.e., prior to knitting, have a non-sueded outer surface. Advantageously, the resulting fabrics knitted with needle 10 are sueded with no extra labor costs or process costs. Further, the resulting fabrics knitted with needle 10 have yarns 14 that are sueded throughout the body of the fabric. In contrast, fabrics exposed to a sueding process after knitting merely have sueded surfaces (i.e., face and/or back).
Since needle 10 provides yarns 14 that are sueded throughout the body of the fabric, the resulting fabric can be produced with substantially no face-to-back differentiation in color and/or hand-feel.
Referring now to FIG. 2 , a method of knitting a sueded fabric according to the present disclosure is generally illustrated by reference numeral 40 . Method 40 includes a first step 42 and a second step 44 . First step 42 includes forming abrasive surface 12 on needle 10 . Second step 44 includes moving yarn 14 across abrasive surface 12 to form fibrils 32 at the surface of the yarn as needle 10 is forming loop 32 from the yarn. Second step 44 is repeated until a plurality of loops 30 are knitted to result in the sueded fabric being knitted.
Forming abrasive surface 12 on needle 10 of first step 42 can include knurling and/or scuffing region 22 of shank 16 . In another embodiment, forming abrasive surface 12 on needle 10 of first step 42 can include applying an abrasive coating or paint to region 22 of shank 16 . In still another embodiment, forming abrasive surface 12 on needle 10 of first step 42 can include applying an abrasive element, such as a layer of emery paper, to region 22 of shank 16 .
Referring now to FIG. 3 , a sueded knitted fabric according to the present disclosure is generally illustrated by reference numeral 50 . Fabric 50 includes a technical face 52 , a technical back 54 , and a knitted body 56 . Fabric 50 is knitted from yarns that are sueded throughout body 56 of the fabric. Thus, fabric 50 has sueded yarns at technical face 52 , technical back 54 , and fabric body 56 . Preferably, fabric 50 has substantially the same color and/or hand-feel at face and back 52 , 54 . Fabric 50 can be a weft knitted fabric or a warp knitted fabric.
It should be recognized that needle 10 is described herein by way of example as having abrasive surface 12 at front region 22 so that the needle suedes loop 30 during the casting off of the knitted loop. Of course, it is contemplated for needle 10 to have abrasive surface 12 at any desired region of the needle so that the needle suedes yarn 14 during any part of the knitting cycle.
Needle 10 is illustrated in FIGS. 4 through 9 during various stages of the knitting cycle.
FIG. 4 shows needle 10 in a rest or ground position of the knitting cycle. Here, needle 10 is stationary with a previously knitted loop 30 enclosed in hook 18 by latch 20 , which is in a closed position.
FIG. 5 shows needle 10 moving upwards in first direction 26 and in a tuck height position of the knitting cycle. In the tuck height position, knitted fabric 32 is held stationary as latch 20 is moved to an open position. Needle 10 continues to move upward until it reaches a clearing height position as shown in FIG. 6 . In the clearing height position, needle 10 is ready to receive a new yarn 14 .
Needle 10 is shown in a yarn feeding position of the knitting cycle in FIG. 7 . Here, needle 10 is moved downwards in first direction 26 so that the new yarn 14 is laid into hook 18 and latch 20 is moved to its closed position, forming a new loop therein. As the new loop is pulled downward by needle 10 , the needle pulls the new loop through the old loop. Once needle 10 reaches its cast off position as shown in FIG. 8 , the old loop is cast off into fabric 32 and the needle continues downward to the knock over position of the knitting cycle as shown in FIG. 9 .
Advantageously, needle 10 can include abrasive surface 12 at any region so that yarn 14 is sueded as the needle is moved through all, or any selected portion of the knitting cycle. For example as shown in FIG. 10 , needle 10 can include abrasive surface 12 at an inner region 34 of hook 18 and/or an inner region 36 of latch 18 so that yarn 14 is sueded as the needle is moved between the rest position to the clearing height position, or any portions thereof. Also, needle 10 can include abrasive surface 12 at an outer region 38 of latch 18 so that yarn 14 is sueded as the needle is moved between the clearing height position and the cast off position, or any portions thereof. Accordingly, the abrasive surface 12 in contact with yarn 14 during knitting causes the yarn 14 to be partially sueded in a continuous path along the eater surface of the yarn as the yarn forms the loops during the knitting cycle. As can he understood, then, the loops formed during knitting would have partially sueded outer surfaces.
It should also be noted that the terms “first”, “second”, “third”, “upper”, “lower”, and the like may be used herein to modify various elements. These modifiers do not imply a spatial, sequential, or hierarchical order to the modified elements unless specifically stated.
While the present disclosure has been described with reference to one or more exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiment(s) disclosed as the best mode contemplated, but that the disclosure will include all embodiments falling within the scope of the appended claims. | A sueded knitted fabric is provided, comprising a technical face, a technical back, and a knitted body extending between the technical face and the technical back. The technical face, technical back, and knitted body comprise sueded yarns throughout. | 3 |
BACKGROUND OF THE INVENTION
Three-dimensional knit products with comparatively expensive structure, such as stockings, are currently made from several knit or cut segments that are combined with each other by sewing or stitching at their edges. Various other working steps continuously follow the process of sewing or stitching the individual segments together, which consequently cause additional costs.
Summary of the Invention
It is an object of the present invention to provide an improved knit article or article of clothing that reduces the undesirable effects of the above-described disadvantages.
According to the invention the knit article has several spatially overlapping structures and is made in a continuous knitting process on a knitting machine with at least two opposing needle beds as a seamless tubular manufactured product. Scarcely any additional working steps are necessary with this knit product. The knit product can, for example, be a hosiery product, or stockings, but it can also be a medical or orthopedic device, such as support hose or a kneecap. Also knit engineering products, such as tubular T-joint elements and protective clothing made from aramide thread material, are within the scope of the present invention. The knit product can be adjusted to the desired spatial geometry by a uniform distribution of loop rows of different width and/or take-up operations, such as narrowing or covering, and/or by a variation in loop size. Nearly any predetermined spatial structure may be formed by this method, without forming a seam or weak place in the knit article. The knit article can have at least one region with a definite cross elasticity, which is formed by binding weft thread in the knit article. The manufacture of the knit article with reinforced regions is possible by knitting a reinforcing thread into it. The knit article can also have at least one stiffened region, which is formed by knitting a pile structure into it. Furthermore the knit article can be provided with at least one opening in its surface, for example for a zipper or fasteners, or also at least one pocket-like structure. Individual regions of the knit article can also be made from a thread material of high absorptivity or other specific properties. The knit pattern and the interweaving type may be of any arbitrary type.
BRIEF DESCRIPTION OF THE DRAWING
The objects, features and advantages of the present invention will be explained in more detail by the following examples with reference to the drawing, in which
FIGS. 1 a , 1 b and 1 c are respective front, side and rear views of a hosiery article according to the invention;
FIGS. 2 a , 2 b and 2 c are respective plan views of different embodiments of a foot region of the hosiery article shown in FIGS. 1 a , 1 b and 1 c ;
FIG. 3 is a diagrammatic illustration of a looping process for making a knit article with imitation weft threads;
FIG. 4 is a diagrammatic illustration of a looping or stitching process for making a knit article with a weft thread binding technique; and
FIG. 5 is a diagrammatic illustration of a stitching process for making a knit article with a pile structure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The hosiery article 20 of FIGS. 1 a to 1 c comprises a body region 1 , a leg region 2 and a foot region 3 . All of these regions are essentially spatial, tubular structures that are seamlessly connected with each other. The seat region 9 , the hip region 10 , the belly region 11 , the center region 12 , the leg 13 and the foot region 14 can be fit exactly to the body shape by take-up, take-off and spinning techniques. The stitching or looping for that can be started both in the foot caps 4 and the waist band 5 . When the foot cap 4 is started, the waist band can be formed with any conceivable stitching or looping method. The band may be finished for example by means of looping or stitching techniques. When the looping is started in the band, the final series of loops or loop row is located on the underside 6 , the upper side 7 of the front side 8 of the foot cap 4 . The hosiery article 20 can also be strengthened in the body region 1 and for example in the region of the heel and the foot cap 4 . Also strengthening or reinforcing threads can be stitched into these regions. If the hosiery article also fulfills a support function, it can be provided with an exact predetermined elasticity by introducing suitable weft threads in the individual regions. Inclusion of absorptive regions is possible by using a bulk or volumetric stitching technique and suitable thread materials. Of course not only complete hosiery articles may be made in this way but also any arbitrary portion between the waist band 5 and the foot cap 4 , such as support stockings, hose or medicinal knee caps and the like may be manufactured by this method. Also other knit articles serving generally as clothing and engineering products which may be made by weaving and knitting are included within the scope of the invention.
FIG. 3 describes a looping process for imitating introduction of weft thread or yarn to make regions of exactly predetermined elasticity in the knit article of the invention. No special weft threads are used. Furthermore the thread in row 1 , which can also be an elastic thread, is taken up by every second needle of the rear needle bed H. Subsequently each needle of the rear needle bed H forms a loop with the thread in row 2 , before each second needle of the front needle bed V takes up the thread in row 3 . In row 4 a loop is formed in the thread with every needle of the front needle bed V. The predetermined elasticity of the knit product is obtained by the taking of the thread with every second needle of the front and rear needle bed V, H. The hosiery depth determines the length of the thread introduced into it. The longer the thread, the more the knit article stretches. The desired elasticity is thus very accurately established in this way.
A weft thread binding technique is shown in FIG. 4 with which a desired cross elasticity of the knit article can be obtained. A loop is formed in row 1 with the thread by every second needle of the rear needle bed H. The choice of needles that form the loop depends on the pattern. Subsequently the loops of every second needle of the rear needle bed H are hung on the front needle bed V. In row 3 a weft thread 30 , which can advantageously be an elastic thread, is laid over the knit thread. In row 4 those loops which had been hung on the front needle bed V are returned to the originating needles in the rear needle bed H, whereby the weft thread 30 is combined in the knit article.
FIG. 5 illustrates the production of a pile structure by which the knit article can be stiffened in various regions. In row 1 a smooth or flat stitch is formed with all the needles in the front and rear needle beds V, H. A first, second and third pile thread 31 , 32 and 33 are laid in stitching or loops on the rear and front needle beds H, V. Subsequently in row 5 a straight stitch is formed on the front and rear needle beds V, H with all the needles and because of that the pile threads are combined in the knit article.
The present invention is also described in German Patent Application 197 43 074.0 of Sep. 30, 1997, which is incorporated here by reference and forms the basis for a claim of priority under 35 U.S.C. 119 for the appended claims.
While the invention has been illustrated and described as embodied in a knit article having several spatially overlapping structures made in a continuous knitting process, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of the prior art, fairly constitute essential characteristics of the generic and specific aspects of the present invention.
What is claimed is new and desired to be protected by Letters Patent is set forth in the appended claims. | The knit article is provided with several spatially overlapping structures. It is made by a continuous knitting process on a knitting machine with at least two opposing needle beds (H,V) as a seamless tubular manufactured product. | 3 |
RELATED APPLICATIONS
This application is the national stage entry, under 35 USC 371, of PCT application PCT/EP2009/008462, filed on Nov. 27, 2009, which claims the benefit of the Dec. 17, 2008 priority date of DE 10 2008 062 385.7, the contents of which are herein incorporated by reference.
FIELD OF INVENTION
The invention relates to testing containers, and in particular, to testing containers closed by a security element.
BACKGROUND
It is a common and well-known practice to close a filled container at its container opening with a container closure that is simultaneously also provided with a security element. This assures the quality and originality of the product and is therefore referred to henceforth as either the “originality-security element” or the “tamper-evident band.”
When a container is closed mechanically, the originality-security element interlocks on the container so that it is only possible to open the container and/or the container closure by detaching the originality-security element from the closure and/or destroying the element. As a result, the opening of the container is indicated with relative certainty.
In the case of a container closure that can be processed mechanically, in particular in the case of cap-type closures for bottles or similar containers, the originality-security element usually comprises a quality or originality-security ring that is provided, for example, on the open side of the cap-type container closure or of the closure body. On application of the container closure to a container, for example when the container closure in the form of a screw closure is screwed on, the security ring engages from behind in the area of the container's opening and/or on its neck in an interlocking manner.
In the case of screw closures for mechanical closure of containers, it is known to produce the originality-security ring and the closure body of the container closure in a single piece and to provide at least one ring-shaped predetermined break-line between the originality-security ring and the closure body. It is also known to design the originality-security ring in such a way that it consists of several ring segments that are connected to each other by pre-determined breaking sections separated by predetermined break-lines. The predetermined break-lines and sections are, for example, formed by reducing the material thickness and/or by perforation. As a result, opening the container closure not only detaches the originality-security ring from the closure cap, but also damages it.
Since originality-security elements are thus constructively designed such that they are destroyed when stressed, it is difficult to completely prevent security elements from sometimes being damaged during the mechanical closure of containers. This leads to irritation and complaints both from retailers in the trade and from consumers. It also leads to increased costs. Damage of this kind to the originality-security elements is thus undesirable.
SUMMARY
The invention provides a method for identifying damaged originality-security elements, or tamper-evident bands, on containers. This reduces irritations and complaints due to damaged originality-security elements or tamper-evident bands on containers.
In one aspect, the invention features a method for checking filled containers that have been sealed with container seals. Such a method includes checking integrity of a tamper-evident band provided on a container seal that is retained on a container in at least one of a form locking manner and a force locking manner when the container is sealed, wherein the container can only be opened by at least one of removal and destruction of the tamper-evident band, wherein checking integrity of the tamper-evident band comprises transporting a container to a measurement and control position, illuminating the tamper-evident band, and, using an optoelectronic sensor system, detecting an image of at least a sub-region of the tamper-evident band, wherein illuminating the tamper-evident band comprises illuminating the tamper-evident band from inside the container, and wherein illuminating the tamper-evident band from inside the container comprises directing an illumination beam that originates at a light source exterior to the container through a container wall of the container and into an interior of the container at a region of a container seal.
Practices of the invention include those in which detecting an image of at least a sub-region of the tamper-evident band includes using at least one optoelectronic sensor in the optoelectronic sensor system, those in which detecting an image of at least a sub-region of the tamper-evident band comprises recording an image of the tamper-evident band in at least a sub-region thereof, and those in which detecting an image of at least a sub-region of the tamper-evident band comprises recording an image of the tamper-evident band using at most a single optoelectronic sensor by deflecting light from a first optical beam deflection element and deflecting light from a second optical beam deflection element.
In some practices, container is made of a translucent material, in which case the method further comprises illuminating a region of the tamper-evident band from inside the container.
In other practices, a region of a container circumferential surface lies opposite the region of the tamper-evident band. In such cases, the method comprises directing a light beam from the light source so as to strike the region,
Yet other practices include directing the light beam along a direction that, at least outside the container, forms an angle of less than 90 degrees relative to at least one of a container axis and a container seal, wherein the angle opens toward a container base lying opposite the container seal.
Additional methods include determining beam refraction resulting from passage of the beam through a container wall, and taking the beam refraction into account, directing the beam along a direction selected such that the beam strikes a back surface of the band directly.
Yet other embodiments, include determining beam refraction on the container wall and/or on the border surface between the container wall and the filler, and, taking the beam refraction into account, directing the beam along a direction selected such that the beam strikes a back surface of the band indirectly as a result of reflection from an inner surface of the container.
Yet other practices include directing an illumination beam comprises directing the beam toward a base of the container.
Practices of the invention also include generating a signal indicative of detecting a container having a defective tamper-evident band, and, in response to the signal, rejecting the container.
Also among the practices of the invention are those in which the tamper-evident band is provided on a sealing body, those in which it is provided on a cap, and those in which the containers are bottles.
In another aspect, the invention features an apparatus for processing containers Such an apparatus includes a device for checking integrity of tamper-evident bands provided on container seals that are used to seal filled containers in either a form-locking manner or a force-locking manner, and in which opening the container is only possible by either removing or destroying the tamper-evident band. The integrity-checking device has a measurement and control position, a transporter, a light source, and an optoelectronic sensor system. The transporter is configured for transporting a container to the measurement and control position. The light source, which is disposed outside the container, emits an illumination beam that illuminates the tamper-evident band by directing it through a container wall and into an interior of the container to a region of the container seal, thereby illuminating the tamper-evident band from the interior of the container. The optoelectronic sensor system then detects an image of at least a sub-region of the tamper-evident band.
In some embodiments, the optoelectronic sensor system is configured for detecting numerous sub-regions of the tamper-evident band.
In other embodiments, the optoelectronic sensor system includes a shared optoelectronic sensor and an optical system. In these embodiments, the optical system comprises beam deflection elements that cooperate with the shared optoelectronic sensor to simultaneously record numerous sub-regions of the tamper-evident band.
In yet other embodiments, the optical system has a first optical deflection element, a second optical deflection element, and a third optical deflection element.
The first optical beam deflection element is displaced laterally from the measurement and control position. The second optical beam deflection element adjoins the first optical beam deflection element along a beam path of the illumination beam. The first and second beam deflection elements are distributed about the measurement and control position. The third optical beam deflection element is provided in the beam path between the second beam deflection element and the optoelectronic sensor. The third beam deflection element is disposed to intersect an optical axis of the optoelectronic sensor, which is also an axis of the measurement and control position.
Among these embodiments are those in which the container has a container base and a container seal disposed opposite the container seal. In such embodiments, the light source is disposed beneath the first optical deflection element. A beam incident on the first optical deflection element lies in a plane containing the optical axis and forms an angle with the optical axis that is less than 90° and that opens toward a plane defined by the container base.
Other embodiments include a housing, and a supporting structure for the housing, the supporting structure has a base pillar. At least one of the first beam deflection element and the light source is contained in the base pillar, which is disposed to a side of a movement path of the container. The housing, which accommodates the sensor is disposed above the movement path for the container.
In some embodiments, the illumination beam is a bundled light beam for illuminating the tamper-evident band, and wherein the bundled light beam is to be detected by the optoelectronic sensor system. Among these are embodiments in which the illumination beam is directed so as to illuminate the tamper-evident band from inside the container when the container is a translucent container that is located at the measurement and control position.
In another embodiment, the device for checking integrity of tamper-evident bands is a constituent of a container-processing machine. The container-processing machine can be, but is not limited to a container-filling machine, a container-sealing machine, a container-labeling machine, and a container-packaging machine. In these embodiments the device is disposed in the system along a direction of transport for containers to be processed by the container-processing machine.
Refinements, advantages and potential applications of the invention can also be derived from the following description of embodiments and from the figures. At the same time, all of the features described and/or illustrated are, per se, or in any combination, in principle the subject matter of the invention, regardless of their summary in the claims or back references thereto. The content of the claims is also made an integral part of the description.
DESCRIPTION OF THE FIGURES
The invention will next be explained in more detail with the aid of the figures, on the basis of one embodiment. In the figures:
FIG. 1 is a simplified partial diagram form and in section, a container closure with an originality-security ring arranged on a mouth of a container or a bottle;
FIG. 2 is a top view of an inspection device according to the invention for testing the originality-security rings of closed containers;
FIG. 3 shows the inspection device from FIG. 2 in perspective view; and
FIG. 4 is a section along the line I-I in FIG. 2 .
DETAILED DESCRIPTION
The figures show containers 1 , generally bottles, which are preferably made from a light-permeable or translucent material. Examples of such materials include glass and translucent plastics, such as PET. Following filling with a bulk product, for example with a beverage, each container 1 is closed with a cap-type container closure 2 , for example by screwing on the container closure 2 or a closure body 3 thereof onto an external thread on a container neck 1 . 1 , as shown in FIG. 1 .
Each container closure 2 includes a cap-type closure body 3 and an originality-security ring 4 , also referred to as a “tamper-evident band,” which is produced integrally with the closure body 3 via a ring-shaped predetermined break-line 5 concentrically surrounding a closure and container axis BA. The break-line 5 is formed by a perforation with several slit-like breaks arranged in sequence along the predetermined break-line 5 , and is made, for example, of plastic or a metallic material. The originality-security ring 4 is provided on the inside with several projections or catches 6 that are distributed around the axis of the closure and that engage from behind in a positive fit with a ring-type projection 7 that stands away from the perimeter area of the container mouth 1 . As a result, it is only possible to open the container 1 by at least partially separating the originality-security ring 4 along the predetermined break line 5 and/or by at least partially destroying the originality-security ring 4 .
The container closures 2 are designed in such a way that their originality-security rings 4 are destroyed, as described above, under the stress that occurs during opening. However, it also occasionally happens that the originality-security ring 4 is damaged during closing, rather than opening the container. For example, it may be damaged while being screwed onto the container neck 1 . 1 .
This can give the consumer the impression that the container has already been opened, even though it has not.
FIG. 3 shows an inspection device 8 for checking the intactness of the originality-security rings 4 on the container closures after a container 1 has been filled and closed. Preferably, this inspection takes place before each closed container 1 is passed on for further processing. Examples of machines used for further processing include a labeling machine, a machine for placing the containers 1 in transport crates (bottle crates), and a machine that forms multipacks of several containers. Consequently, it is especially advantageous if the check of the intactness of the originality-security rings 4 takes place prior to delivery or shipping of the filled and sealed containers 1 to customers, for example to drink outlets, etc.
Referring to FIG. 2 , to carry out the inspection, the containers 1 , which are, for example, standing upright on a conveyor 9 , i.e. with their container axis BA vertically oriented, are moved continuously or in pulses in a transport direction A through the inspection device 8 and thereby also through a measurement and control position 8 . 1 of the inspection device 8 . At the measurement and control position 8 . 1 , an optoelectronic sensor system 10 captures image data concerning the originality-security ring 4 . The optoelectronic sensor system 10 delivers this data for processing by an image-processing system 11 . The image processing system 11 comprises or is aided by a computer.
Processing by the image-processing system 11 includes evaluating the actual data delivered by the sensor system 10 on each checked originality-security ring 4 . For example, the actual data delivered on each checked originality-security ring 4 is compared with target data or values stored in a memory of the image processing system 11 . If a fault is found on an originality-security ring 4 , the image processing system 11 takes appropriate action. In one example, the image-processing system 11 triggers a fault signal, which then leads e.g. to the container 1 with the closure with the faulty originality-security ring 4 being expelled from a product line of a plant that is using the inspection device 8 .
Referring to FIG. 3 , the inspection device 8 , in the illustrated embodiment, has a two-part housing 12 in which the sensor system 10 is housed and that essentially consists of a solid housing lower part 13 and a housing upper part 14 . The housing upper part 14 is detachably fixed to the housing lower part 13 via toggle fasteners 15 . The housing lower part 13 is relatively solid by design. In the embodiment shown, the housing lower part 13 is in the form of a trough, with a square base 16 and a perimeter wall 17 . The housing upper part 14 closes off the housing part 13 on the open upper side is designed in the form of a hood, with a square upper wall 18 and a perimeter wall 19 , best seen in FIG. 4 .
The housing 12 , which is thus square in top view, is arranged with four feet 20 , each of which is a hollow cylinder. The housing underside, formed by the square base 16 , lies above the movement path of the containers 1 moved through the inspection device 8 . The feet 20 are located to the side of the conveyor 9 near the corners of the square base 16 . Also, the arrangement is made in such a way that two sides of the housing 12 are oriented parallel to the transport direction A of the conveyor 9 and two sides of the housing 12 are oriented perpendicular to the transport direction A.
Referring now to FIG. 4 , an electronic camera 22 with a lens system 23 , which is directed at the housing base 16 , is arranged on a supporting frame 21 in the interior of the housing 12 . This is done in such a way that the camera 22 and the lens system 23 have a vertically oriented with common optical axis OA. The optical axis OA defines both an axis of symmetry of the sensor system 10 and an axis of the measurement and control position 8 . 1 in the form that each container 1 which has reached this measurement and control position 8 . 1 , is arranged with its container axis BA coaxial, or essentially coaxial with the axis OA.
In the embodiment shown, the point at which the diagonals of the square housing base 16 intersect and the point at which the connecting lines between the axes of the feet 20 that lie diagonally opposite each other in relation to the square housing base 16 intersect both lie on the optical axis OA.
A multi-mirror optical beam deflection element 24 is provided underneath the camera 22 and separated from it by a distance from it in the vertical direction. The multi-mirror optical beam deflection element 24 has a mirror body shaped like a pyramid having a square base. Four mirror surfaces 24 . 1 are on the mirror body.
The multi-mirror optical beam deflection element 24 is arranged with its axis in the optical axis OA so that each mirror surface 24 . 1 of a beam deflection element 24 lies opposite and at a distance from a first mirror surface 25 . 1 of a mirror 25 that is arranged inside the housing 12 and above the foot 20 in which the beam deflection element 24 is disposed. The first mirror surface 25 . 1 lies opposite a second mirror surface 26 . 1 of a mirror 26 that is arranged in a foot element 20 behind a window 27 provided in the foot element 20 and sealed off by a transparent protective pane made from a transparent material, for example glass. An opening 28 in the base 16 between the beam deflection elements 25 and the mirror 26 allows optical communication therebetween.
The mirror 26 and its mirror surface 26 . 1 are located at a height level N at which the originality security rings 4 on the containers 1 to be checked are moved through the measurement and control position 8 . 1 . Via the mirror surfaces 24 . 1 , 25 . 1 and 26 . 1 , the beams imaging the originality security ring 4 at the measurement and control position 8 . 1 are each subjected to multiple deflection by 90°. This results in a ray path that starts from the measurement and control position 8 . 1 , radially outwards in relation to the optical axis OA, proceeds subsequently by deflection at the mirror surface 26 . 1 parallel to the optical axis OA upwards through the opening 28 at the mirror surface 25 . 1 , from this, in relation to the optical axis OA, radially inwards to one of the mirror surfaces 24 . 1 , where it is deflected into the lens system 23 of the camera 22 .
Due to the arrangement of the mirrors 26 , an image is captured of the originality security ring 4 from the side. With corresponding design of the sensor system 10 or with corresponding arrangement of the mirrors 26 , it is also possible to capture an image of the originality-security rings 4 from another viewing direction, for example at an angle from above or at an angle from below.
A light source 29 is disposed in the foot element 20 , under the mirror 26 , and behind the window 27 . As a result, the light source 29 is likewise protected against contamination. This light source 29 emits an intensely focused illumination light beam 30 directed upwards at an angle starting from the light source 29 towards a point at which it intersects the optical axis OA. The light beam 30 illuminates the container closure 2 , at least on the area with the originality-security ring 4 on the inside of the container closure, and in fact through the container 1 , and in certain cases, depending on the application, also through the bulk product contained in the container 1 , thus from the inside of the container 1 . As a result, wherein from the outside of the container, the container closure 2 , and thus, in particular, the originality-security ring 4 , appears to be lit from behind. In order to achieve this, the light beam 30 preferably impinges in a direction on the side of the originality-security ring 4 facing towards the interior of the container. This direction is coaxial with the optical axis of the mirror 26 of the respective mirror system formed by the mirrors 25 and 26 , or else encloses an angle considerably smaller than 90° with this optical axis.
The mirror arrangement formed by the mirrors 25 and 26 is provided four-fold, i.e. a mirror 25 is arranged over each foot element 20 and the opening 28 provided there, to which a mirror 26 is assigned in the foot element 20 . Furthermore, in each foot element 20 a light source 29 is provided to emit the intensely bundled light beam 30 , and in such a way that the container closure 2 of the respective container 1 located at the measurement and control position 8 . 1 is lit from behind by the light source 29 in the area of its originality-security ring 4 for imaging via one respective mirror 26 , the light source being provided in the foot element 20 located diagonally opposite this mirror 26 .
By pivoting the light source 29 , the beams 30 can be adjusted in such a way that the refraction that these light beams 30 undergo when entering the respective container 1 at its surface or perimeter area and the refraction arising from the interface between the container wall and the liquid bulk product, can be taken into account for an optimal illumination of the originality-security rings 4 from behind.
Due to the illumination of the originality-security rings 4 from behind, i.e. from the inside of the respective containers 1 , the backlight thus generated gives rise to an especially contrast-rich 360° image of the respective originality-security ring 4 captured with the camera 22 via the mirrors 24 , 25 and 26 . This contrast-rich image makes it possible for the image processor 11 to reliably identify any faults or damage on originality-security rings 4 . The illumination of the respective originality-security ring 4 from behind also leads to especially contrast-rich and clear images because the container closures 2 usually consist of a material that is non-translucent or the translucency of which is considerably less than that of the material from which the containers 1 are made.
The invention has been described above on the basis of one embodiment. It goes without saying that numerous modifications and alterations are possible.
For example, it has been assumed above that the intensely bundled light beams 30 are generated by light sources 29 that are arranged at the side of the container located respectively at the measurement and control position 8 . 1 , and in such a way that the light beams 30 strike the respective container 1 or its perimeter wall at an angle from below, and in fact in the upper area of the container 1 , e.g. in the area of the container shoulder or container breast. In principle, embodiments are also possible in which the originality-security ring 4 to be checked is illuminated from behind through the container base.
It is also possible to provide several light sources 29 to illuminate that area of the originality-security ring 4 that is to be captured with the camera 22 or with another optoelectronic sensor unit.
It has also been assumed above that the optoelectronic system for capturing the condition of the respective originality-security ring 4 is a camera system with an electronic camera 22 . However, this system may also have several electronic cameras or consist of a system with which the respective originality-security ring 4 and its condition are optically captured in some other way, for example by scanning with at least one laser beam, etc.
The optical beam deflection elements to achieve a 360° capture or 360° image of an originality-security ring 4 have been described above as mirrors 24 , 25 and 26 . However, other optical beam deflection elements can also be used. | The invention relates to a method for testing bottles or the like containers ( 1 ) filled with a bulk material and mechanically closed by means of a container closure ( 2 ), the container closures ( 2 ) each comprising an original security ring ( 4 ) held on said container ( 1 ) in the closed state thereof in an interlocking and/or force-fit manner, such that opening the container ( 1 ) is possible only by separating and/or destroying the originality security ring ( 4 ), characterized in that the containers ( 1 ) are tested by means of at least one optoelectronic sensor system ( 10 ) after filling and closing for intactness of the originality security element ( 4 ). | 1 |
This invention was made in the course of work under a grant or award from the U.S. government; therefore, the U.S. government has rights in the invention.
This is a continuation-in-part of application Ser. No. 07/839,734, filed Feb. 19, 1992, now abandoned, which in turn, is a continuation-in-part of application Ser. No. 07/343,325, filed Apr. 26, 1989, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to therapeutic peptides.
A number of somatostatin analogs exhibiting Growth Hormone-releasing-inhibiting activity have been described in the literature, including analogs containing fewer than the naturally occurring fourteen amino acids. For example, Coy et al. U.S. Pat. No. 4,485,101, hereby incorporated by reference, describes dodecapeptides having an N-terminal acetyl group, a C-terminal NH 2 , D-Trp at position 6, and p-Cl-Phe at position 4. (Herein, when no designation of configuration is given, the L-isomer is intended.)
Abbreviations: Nle=norleucine, Nal-naphthylalanine
SUMMARY OF THE INVENTION
In general, the invention features a linear somatostatin analog of the formula: ##STR2## wherein A 1 is a D- or L-isomer of any of Ala, pyridyl-Ala, Leu, Ile, Val, Met, Nle, Thr, Ser, Trp, β-Nal Phe, o-X-Phe (wherein X═CH 3 , Cl, Br, F, OH, OCH 3 , NO 2 ), p-X-Phe (wherein X═CH 3 , Cl, Br, F, OH, OCH 3 , NO 2 ), 2,4-dichloro-Phe, pentafluoro-Phe;
A 2 is any of Ala, pyridyl-Ala, Leu, Ile, Val, Met, Nle, Trp, β-Nal Phe, o-X-Phe (wherein X═CH 3 , Cl, Br, F, OH, OCH 3 , NO 2 ), p-X-Phe (wherein X═CH 3 , Cl, Br, F, OH, OCH 3 , NO 2 ), 2,4-dichloro-Phe, or pentafluoro-Phe;
A 3 is any of Ala, pyridyl-Ala, Leu, Ile, Val, Met, Nle, Trp, Tyr, β-Nal Phe , o-X-Phe (wherein X═CH 3 , Cl, Br, F, OH, OCH 3 , NO 2 ), p-X-Phe (wherein X═CH 3 , Cl, Br, F, OH, OCH 3 , NO 2 ), 2,4-dichloro-Phe, or pentafluoro-Phe;
A 6 is any of Ala, pyridyl-Ala, Leu, Ile, Val, Lys, Met, Nle, Thr, Ser, Trp, β-Nal, o-X-Phe (wherein X═CH 3 , Cl, Br, F, OH, OCH 3 , NO 2 ), p-X-Phe (wherein X═CH 3 , Cl, Br, F, OH, OCH 3 , NO 2 ), 2,4-dichloro-Phe, or pentafluoro-Phe;
A 7 is any of Ala, pyridyl-Ala, Leu, Ile, Val, Met, Nle, Trp, β-Nal Phe , o-X-Phe (wherein X═CH 3 , Cl, OH, OCH 3 , NO 2 ), p-X-Phe (wherein X═CH 3 , Cl, Br, F, OH, OCH 3 , NO 2 ), 2,4-dichloro-Phe, or pentafluoro-Phe;
A 8 is a D- or L-isomer of any of Ala, pyridyl-Ala, Leu, Ile, Ser, Thr, Val, Met, Nle, Trp, β-Nal Phe, o-X-Phe (wherein X═CH 3 , Cl, Br, F, OH, OCH 3 , NO 2 ), p-X-Phe (wherein X═CH 3 , Cl, Br, F, OH, OCH 3 , NO 2 ), 2,4-dichloro-Phe, or pentafluoro-Phe;
each R 1 and R 2 , independently, is H, lower (1-5 carbon atoms) acyl, or lower alkyl; and R 3 is OH, NH 2 , or lower alkyl; provided that at least one of A 1 and A 2 and at least one of A 7 and A 8 aromatic amino acid; and further provided that A 1 , A 2 , A 7 and A 8 cannot all be aromatic amino acids or a pharmaceutically acceptable salt thereof.
In the formula recited above and in the claims, A 1 stands for an amino acid residue of ═N--CH(R)--C═O-- and each of A 2 through A 8 stands for --NH--CH(R)--C═O--, where R is the identifying group of an amino acid, e.g., R is --CH 3 for Ala.
Preferably, of A 1 and A 2 , only one is an aromatic amino acid; and of A 7 and A 8 , only one is an aromatic amino acid.
In preferred embodiments A 1 is a D-isomer of any of Trp, β-Nal, o-X-Phe (wherein X═CH 3 or OCH 3 ), p-X-Phe (wherein X═CH 3 or OCH 3 ) and A 8 is a D- or L-isomer of any of Ala, pyridyl-Ala, Leu, Ile, Ser, Thr, Val, Met, Nle, o-X-Phe (wherein X═Cl, Br, F, OH, NO 2 ), p-X-Phe (wherein X═Cl, Br, F, OH, NO 2 ), 2,4-dichloro-Phe, or pentafluoro-Phe.
In other preferred embodiments A 1 is a D-isomer of any of o-X-Phe (wherein X═H, Cl, Br, F, OH, or NO 2 ), p-X-Phe (wherein X═H, Cl, Br, F, OH, or NO 2 ), 2,4-dichloro-Phe, or pentafluoro-Phe; and A 8 is a D- or L-isomer of any of Ala, pyridyl-Ala, Leu, Ile, Thr, Val, Met, Nle, Trp, β-Nal, o-X-Phe (wherein X═CH 3 or OCH 3 ), or p-X-Phe (wherein X═CH 3 or OCH 3 ).
In other preferred embodiments A 8 is a D- or L-isomer of any of Thr, Trp, β-Nal, o-X-Phe (wherein X═CH 3 or OCH 3 ), or p-X-Phe (wherein X═CH 3 or OCH 3 ); and A 1 is Phe or a D-isomer of any of Ala, pyridyl-Ala, Leu, Ile, Val, Met, Nle, o-X-Phe (wherein X═H, Cl, Br, F, OH, NO 2 ), p-X-Phe (wherein x═H, Cl, Br, F, OH, NO 2 ), 2,4-dichloro-Phe, or pentafluoro-Phe.
In other preferred embodiments A 8 is a D- or L-isomer of any of Ser, Thr, o-X-Phe (wherein X═Cl, Br, F, OH, or NO 2 ), p-X-Phe (wherein X═Cl, Br, F, OH, or NO 2 ), 2,4-dichloro-Phe, or pentafluoro-Phe; and A 1 is a D-isomer of any of Ala, pyridyl-Ala, Leu, Ile, Val, Met, Nle, Trp, β-Nal, o-X-Phe (wherein X═CH 3 or OCH 3 ), or p-X-Phe (wherein X═CH 3 or OCH 3 ).
More preferably, A 1 ═β-D-Nal or D-Phe; A 2 ═Ala, Phe or p-chloro-Phe; A 3 ═Tyr or Phe; A 6 ═Val, Lys or Thr; A 7 ═Ala or Phe; A 8 ═Thr or D-β-Nal. While a D-isomer is preferred as the C-terminal residue (which is well known in the art to confer stability on the peptides), analogs with an L-isomer at that position are also within the invention. Similarly, the N-terminal residue can either be of D-or L- configuration.
Preferred compounds of the invention include D-phe-p-chloro-phe-Tyr-D-Trp-Lys-Thr-phe-Thr-NH 2 ; D-Phe-p-NO 2 -Phe-Tyr-D-Trp-Lys-Val-Phe-Thr-NH 2 ; D-Nal-p-chloro-Phe-Tyr-D-Trp-Lys-Val-Phe-Thr-NH 2 ; D-Phe-p-chloro-Phe-Tyr-D-Trp-Lys-Val-Phe-Thr-NH 2 ; D-Phe-Phe-Tyr-D-Trp-Lys-Val-Phe-Thr-NH 2 ; D-Phe-Phe-Phe-D-Trp-Lys-Thr-Phe-Thr-NH 2 ; and D-Phe-Ala-Tyr-D-Trp-Lys-Val-Ala-B-D-Nal-NH 2 .
In other preferred embodiments, a therapeutically effective amount of the therapeutic compound and a pharmaceutically acceptable carrier substance, e.g. magnesium carbonate, lactose, or a phospholipid with which the therapeutic compound can form a micelle, together form a therapeutic composition, e.g. a pill, tablet, capsule, or liquid for oral administration to a human patient, a spreadable cream, gel, lotion, or ointment to be applied topically or to be iontorphoretially forced through the skin of a human patient in need of the compound, a liquid capable of being administered nasally as drops or spray, or a liquid capable of intravenous, parenteral, subcutaneous, or intraperitoneal administration. The pill, tablet or capsule can be coated with a substance capable of protecting the composition from the gastric acid in the patient's stomach for a period of time sufficient to allow the composition to pass undisintegrated into the patient's small intestine. The therapeutic composition can also be in the form of a biodegradable or nonbiodegradable sustained release formulation for intramuscular administration. For maximum efficacy, zero order release is desired, and can be obtained using an implantable or external pump, e.g., INFUSOID TM pump, to administer the therapeutic composition.
The compounds of the invention are active in inhibiting the secretion of growth hormone, somatomedins (e.g., IGF-1), insulin, glucagon, and other autoparacrine growth factors or pancreatic growth factors. The compounds of the invention are acyclic and, therefore, stable and resistant to oxidation. In addition, the acyclic nature of the peptide facilitates synthesis and purification, improving efficiency and reducing manufacturing costs.
Other features and advantages of the invention will be apparent from the following description of the preferred embodiments thereof, and from the claims.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The drawings will first be described.
Drawings
FIG. 1 is a graph showing the effects of linear analogs on growth hormone secretion by rat pituitary cells.
FIG. 2 is a graph showing the effects of linear analogs on growth hormone secretion by rat pituitary cells.
STRUCTURE
The compounds of the invention have the general formula recited in the Summary of the Invention, above. They are all octapeptide analogs of somatostatin which have D-Trp at the fourth position and Lys at the fifth position. An octapeptide of this invention contains at least an aromatic amino acid at position A 1 or A 8 and at least an aromatic amino acid at position A 2 or A 7 , but cannot contain an aromatic amino acid at each of A 1 , A 2 , A 7 and A 8 . In other words, while at least one aromatic acid must be present at either terminus, A 1 , A 2 , A 7 and A 8 cannot all be aromatic amino acids.
The compounds can be provided in the form of pharmaceutically acceptable salts. Examples of preferred salts are those with therapeutically acceptable organic acids, e.g., acetic, lactic, maleic, citric, malic, ascorbic, succinic, benzoic, salicylic, methanesulfonic, toluenesulfonic, or pamoic acid, as well as polymeric acids such as tannic acid or carboxymethyl cellulose, and salts with inorganic acids such as the hydrohalic acids, e.g., hydrochloric acid, sulfuric acid, or phosphoric acid.
Synthesis
The synthesis of one therapeutic peptide follows. Other peptides can be prepared by making appropriate modifications, within the ability of someone of ordinary skill in this field, of the following synthetic method.
The first step in the preparation of the peptide
D-Phe-Phe-Phe-D-Trp-Lys-Thr-Phe-Thr-NH.sub.2
is the preparation of the intermediate:
Boc-D-Phe-Phe-Phe-D-Trp-N-benzyloxycarbonyl-Lys-O-benzyl-Thr-Phe-O-benzyl-Thr-benzhydrylamine resin, as follows.
Benzhydrylamine-polystyrene resin (Advanced ChemTech, Inc.) (1.2 g, 0.5 mmole) in the chloride ion form is placed in the reaction vessel of an Advanced ChemTech peptide synthesizer programmed to perform the following reaction cycle:
(a) methylene chloride;
(b) 33% trifluoroacetic acid in methylene chloride (2 times for 1 and 25 min each);
(c) methylene chloride;
(d) ethanol;
(e) methylene chloride; and
(f) 10% triethylamine in chloroform.
The neutralized resin was stirred with Boc-O-benzyl-threonine and diisopropylcarbodiimide (1.5 mmole each) in methylene chloride for 1 hr and the resulting amino acid resin is then cycled through steps (a) to (f) in the above wash program. The following amino acids (1.5 mmole) are then coupled successively by the same procedure:
Boc-Phe, Boc-O-benzyl-Thr, Boc-N-benzyloxycarbonyl-lysine, Boc-D-Trp, Boc-Phe, and Boc-Phe and Boc-D-Phe. After washing and drying, the completed resin weighed 1.70 g.
The resin (1.70 g, 0.5 mmole) is then mixed with cresol (5 ml), dithiothreitol (100 mg) and anhydrous hydrogen fluoride (35 ml) at 0° C. and stirred for 45 min. Excess hydrogen fluoride is evaporated rapidly under a stream of dry nitrogen, and free peptide precipitated and washed with ether. The crude peptide is then dissolved in a minimum volume of 50% acetic acid and eluted on a column (2.5×100 cm) of SEPHADEX G-25 using the same solvent. Fractions containing a major component by UV absorption and thin layer chromatography are then pooled, evaporated to a small volume and applied to a column (2.5×50 cm) of VYDAC octadecylsilane silica (10-15 μM).
The column was eluted with a linear gradient of 10-45% acetonitrile in 0.1% trifluoroacetic acid in water. Fractions are examined by thin layer chromatography and analytical high performance liquid chromatography and pooled to give maximum purity. Repeated lyophilization of the solution from water gives 65 mg of the product as a white, fluffy powder.
The product was found to be homogeneous by hplc and tlc. Amino acid analysis of an acid hydrolysate confirms the composition of the octapeptide.
Other peptides of the invention are prepared in an analogous fashion to those described above.
Effects of Linear Somatostatin Analogs on Growth Hormone Secretion in Cultured Rat Pituitary Cell Dispersion
Octapeptides of the invention are tested for inhibtion of growth hormone-releasing-activity using rat pituitary cells, as follows.
Anterior pituitaries from adult Charles River CD male rats (Wilmington, Mass.) weighing 200-250 g and housed under controlled conditions (lights on from 0500-1900 h), were dispersed and cultured using aseptic technique by modification of previously described methods (Hoefer et al., 1984, Mol. Cell. Endocrinol. 35:229; Ben-Jonathan et al., 1983, Methods Enzymol. 103:249; Heiman et al., 1985, Endocrinology 116:410). Pituitaries were removed from decapitated rats, sectioned, and then placed into a siliconized, liquid scintillation vial containing 2 ml 0.2% trypsin (Worthington Biochemicals, Freehold, N.J.) in sterile-filtered Krebs-Ringer bicarbonate buffer supplemented with 1% bovine serum albumin, 14 mM glucose, modified Eagle medium (MEM) vitamin solution and MEM amino acids (Gibco Laboratories, Grand Island, N.Y.) (KRBGA). All glassware was siliconized as described by Sayers et al., 1971, Endocrinology 88:1063. The fragments were incubated in a water bath for 35 min at 37° C. with agitation. The vial contents then were poured into a scintillation vial containing 2 ml 0.1% DNase (Sigma Chemical Co., St. Louis, Mo.) in KRBGA and incubated for 2 min at 37° C. with agitation. After incubation the tissue was decanted back into the centrifuge tube and allowed to settle. Medium was discarded, and pituitary sections were washed 3 times with 1 ml fresh KRBGA. The cells were then dispersed by gently drawing the fragments into and expelling them out of a siliconized, fire-polished Pasteur pipette in 2 ml 0.05% LBI (lima beam trypsin inhibitor, Worthington Biochemicals). Dispersed cells were filtered through a 630 μm diameter Nylon mesh (Tetko, Elmsford, N.Y.) into a fresh 15 ml centrifuge tube and harvested by centrifugation at 100×g for 1 min. The final speed was attained gradually through a centrifugation period of 17 min.
After centrifugation, medium was discarded and the pelleted cells were resuspended in fresh LBI (2 ml) with a Pasteur pipette. The dispersed cells were then diluted with approximately 15 ml sterile-filtered Dulbecco's modified Eagle medium (GIBCO), which was supplemented with 2.5% fetal calf serum (GIBCO), 3% horse serum (GIBCO), 10% fresh rat serum (stored on ice for no longer than 1 h) from the pituitary donors, 1% MEM nonessential amino acids (GIBCO), gentamycin (10 ng/ml; Sigma) and nyatatin (10,000 U/ml; GIBCO). The cells were poured into a 50 ml round-bottomed glass extraction flask with a large diameter opening and were counted with a lemacytometer (approximately 2,000,000 cells per pituitary) and randomly plated at a density of 200,000 cells per well (Co-star cluster 24; Rochester Scientific Co., Rochester, N.Y.). The plated cells were maintained in the above Dulbecco's medium in a humidified atmosphere of 95% air and 5% CO 2 at 37° C. for 96 h.
In preparation for a hormone challenge, the cells were washed 3× with medium 199 (GIBCO) to remove old medium and U floating cells. Each dose of analog (diluted in normal saline in siliconized test tubes) was tested in the presence of 1 nM GRF(1-29)NH 2 (growth hormone releasing factor) in quadruplicate wells in a total volume of 1 ml medium 199 containing 1% BSA (fraction V; Sigma). After 3 h. at 37° C. in an air/carbon dioxide atmosphere (95/5%), the medium was removed and stored at -20° C. until assayed for hormone content. Growth hormone was measured in a conventional radioimmunoassay using anti-growth hormone antibody.
The effect of 9 different peptides on the release of growth hormone in cultured rat pituitary cells is shown in FIGS. 1 and 2. The peptides DC-25-4 (FIG. 1) and DC-25-24 (FIG. 2) are most active in inhibiting the release of growth hormone. Both DC-25-4 and DC-25-24 contain an electron withdrawing group near one end of the molecule and an electron donating group near the opposite end of the molecule. Peptides DC-23-85 (FIG. 1) and DC-25-16 (FIG. 2), which are not within the present invention, show essentially no activity.
Inhibition of I 125 Somatotropin-release-inhibiting Factor (SRIF-14) Binding by Linear Somatostatin Analogs
Crude membrane preparations were obtained from rat pancreas, cerebral cortex, or human small cell lung carcinoma (NCI-H69) cells by homogenizing (Polytron, setting 6, 15 sec) the tissues or cells in ice-cold 50 mM Tris-HCl and centrifuging twice at 39,000× g (10 min), with an intermediate resuspension in fresh buffer. The final pellets were resuspended in 10 mM Tris-HCl for assay. Aliquots of the membrane preparation were incubated for 25 min at 30° C. with labeled somatotropin-release-inhibiting factor, [ 125 I-Tyr 11 ] SRIF-14 (2000 Ci/mmol, Amersham Corp.), in 50 mM HEPES (pH 7.4) containing bovine serum albumin (10 mg/ml; fraction V, Sigma Chem.), MgCl 2 (5mM), Trasylol (200 KIU/ml), bacitracin (0.02 mg/ml), and phenylmethylsulphonyl fluoride (0.02 mg/ml). The final assay volume was 0.3 ml. The incubations were terminated by rapid filtration through Whatman GF/C filters (pre-soaked in 0.3% polyethylenimine) under reduced pressure. Each tube and filter were then washed three times with 5 ml aliquots of ice-cold buffer. Specific binding was defined as the total [ 125 I]SRIF-14 bound minus that bound in the presence of 200 nM unlabelled SRIF-14.
Table 1 gives results of inhibition of [ 125 I]SRIF-14 binding by linear peptides of the invention. The concentration of [ 125 I]SRIF-14 was approximately 0.05 nM. (Values in parenthesis indicate the number of independent determinations.) The IC 50 (concentration of analog resulting is 50% competitive inhibition) in nM values are indicated for pancreas, small cell lung carcinoma (SCLC), and brain. The results show that analogs DC-25-4 and DC-23-99 are particularly effective in inhibiting the binding of I 125 SRIF-14. Peptide DC-23-85, which is not within the invention, inhibits the binding of I 125 SRIF-14 only poorly.
Use
When administered to mammals, particularly humans, (e.g. orally, topically, intravenously, parenterally in a sustained release, biodegradable or nonbiodegradable form, nasally, or by suppository), the compounds can be effective to inhibit growth hormone release as well as to inhibit somatomedins (e.g., IGF-1), insulin, glucagon, other autoparacrine growth factors or pancreatic exocrine secretion, and to therapeutically affect the central nervous system.
The compounds can be administered to a mammal, e.g. a human, in the dosages used for somatostatin or, because of their greater potency, in smaller dosages. The compounds of the invention can be used for the treatment of cancer, particularly growth hormone-dependent cancer (e.g., bone, cartilage, pancreas (endocrine and exocrine), prostate, or breast), acromegaly and related hypersecretory endocrine states, or of bleeding ulcers in emergency patients and in those suffering from pancreatitis or diarrhea. The compounds can also be used in the management of diabetes and to protect the liver of patients suffering from cirrhosis and hepatitis. The compounds can also be used to treat Alzheimer's disease, as analgesics to treat pain by acting specifically on certain opiate receptors, and as gastric cytoprotective compounds for ulcer therapy. The compounds can also be used to treat certain types of mushroom poisoning.
The compounds can also be used to treat diabetes-related retinopathy. The anti-cancer activity of the compounds may be related to their ability to antagonize cancer-related growth factors such as epidermal growth factor.
The compounds can be administered to a mammal, e.g., a human, in a dosage of 0.01 to 1000 mcg/kg/day, preferably 0.1 to 100 mcg/kg/day.
Mechanism
The activity of previously described analogs of somatostatin is dependent on the presense of a disulfide linkage between cysteine residues located at or near the ends of the peptide, see, e.g., Coy et al. U.S. Pat. No. 4,485,101, hereby incorporated by reference. The disulfide linkage results in a cyclic conformation necessary for activity.
The inclusion of a disulfide linkage is an undesirable feature in these synthetic peptides in that the step favoring synthesis of the disulfide linkage imposes a dramatic decrease in the overall yield of the synthesis. Furthermore, the disulfide linkages are subject to oxidation and thus result in a less stable product.
The instant invention avoids the use of disulfide linkages and their attendant drawbacks. The octapeptides of the instant invention utilize non-covalent interactions between the side chains of critically positioned constituent amino acid residues to confer a hairpin or quasi-cyclic conformation on the peptides.
The side chains and substituted side chains of the amino acid residues of the instant invention are subject to two types of interactions that tend to confer the desired tertiary structure on the peptide. The first type of interaction occurs when amino acids bearing hydrophobic side chains are located at or near both ends of the peptide. Peptides of this structure exploit the tendency of hydrophobic moieties to avoid contact with polar substances. Interactions between the hydrophobic groups at each end of the peptide, favored over interactions between these groups and the polar solvents of physiological environments, confer a hairpin or quasi-cyclic configuration on the peptide.
The second type of interaction arises as a result of the interaction of electron-donating and electron-withdrawing moieties of amino acids at opposite ends of the peptide. The invention features peptides in which an amino acid possessing an electron-donating group resides in one end region of the peptide while an amino acid possessing an electron-withdrawing group resides in the other end region of the peptide. The attraction between the electron-donating group, at one end of the peptide, and the electron-withdrawing group, at the other end of the peptide, acts to confer a hairpin or quasi-cyclic structure on the peptide. Both hydrophobic-hydrophobic interactions and electron donor-elctron withdrawer interactions may be active in a given peptide.
Other embodiments are within the following claims.
TABLE I______________________________________TABLE 1Inhibition of I.sup.125 SRIF-14 binding by linearanalogs of somatostatinIC.sub.50 (nM)Analog Pancreas SCLC Brain______________________________________Somatostatin 0.53 (5) 4.2 (5) 0.53 (3)BIM-23053/DC-25-4 2.8 (2) 2.2 (1) 109BIM-23052/DC-23-99 9.4 (1) 1.2 (1) 7.3 (1)BIM-23049/DC-23-76 9.2 (3) 2.1 (1) >10,000 (1)BIM-23051/DC-23-89 34 (2) 15 (1) >10,000 (1)BIM-23050/DC-23-85 264 (1) -- 2,189 (2)______________________________________
Results are expressed as the concentration in nM of analog that gives 50% inhibition of I 125 SRIF-14 binding (IC 50 ). The numbers in parantheses indicate the number of trials. The structure of the analogs is as follows: BIM-23049/ DC-23-76--β-D-Nal-Ala-Tyr-D-Trp-Lys-Val-Ala-Thr-Nh 2 ; BIM-23050/DC-23-85-n-methyl-D-Ala-Tyr-D-Trp-Lys-Val-Phe-NH 2 ; BIM-23051/DC-23-89-D-Phe-Ala-Phe-D-Trp-Lys-Thr-Ala-Thr-NH 2 ; BIM-23052/DC-23-99-D-Phe-Phe-Phe-D-Trp-Lys-Thr-Phe-Thr-NH 2 ; BIM-23053/DC-25-4-D-Phe-Ala-Tyr-D-Trp-Lys-Val-Ala-β-D-Nal-NH 2 . The structure of SRIF-14 is: Ala-Gly-Cys-Lys-Asn-Phe-Phe-Trp-Lys-Thr-Phe-Ser-OH. | Linear peptide analogs of somatostatin having the formula: ##STR1## As an example, D-Phe-Phe-Phe-D-Trp-Lys-Thr-Phe-Thr is covered by the above formula (i.e., R 1 is H, R 2 is H, A 1 is D-Phe, A 2 is Phe, A 3 is Phe, A 6 is Thr, A 7 is Phe, A 8 is Thr, and R 3 is NH 2 ). | 8 |
The present invention relates to the quilting of patterns on multiple layer materials, and particularly to the stitching of 360° patterns on thick multilayer materials such as mattress covers.
BACKGROUND OF THE INVENTION
Quilting is a special art in the general field of sewing in which patterns are stitched through a plurality of layers of material over a two dimensional area of the material. The multiple layers of material normally include at least three layers, one a woven primary or facing sheet having a decorative finished quality, one a usually woven backing sheet that may or may not be of a finished quality, and one or more internal layers of thick filler material, usually of randomly oriented fibers. The stitched patterns maintain the physical relationship of the layers of material to each other as well as provide ornamental qualities. Quilting is performed on the customary quilts or comforters and on the covers of mattresses, for example. In the stitching of quilts for these two applications, two different approaches are typically used. Both approaches use stitches that employ both a top and a bottom thread.
Single needle quilters of the type illustrated and described in U.S. patent application Ser. No. 08/497,727, filed Jun. 30, 1995 U.S. Pat. No. 5,640,916 entitled Quilting Method and Apparatus and those patents cited and otherwise referred to therein are customarily used for the stitching of comforters and other preformed rectangular panels. Such single needle quilters typically use a pair of cooperating lock stitch sewing heads, one carrying a needle drive that is typically positioned above the fabric and one carrying a bobbin that is opposite the fabric from the needle, with both heads being mechanically linked to move together in two dimensions, relative to the panel, parallel to the plane of the panel. A common arrangement of this type of quilting apparatus is to support the panel of fabric on a longitudinally moveable shuttle with the sewing heads moveable transversely of the panel to provide two dimensional stitching capability of the pattern on the panel.
Multiple needle quilters of the type illustrated in U.S. Pat. No. 5,154,130 are customarily used for the stitching of mattress covers, which are commonly formed from multi-layered web fed material. Such multi-needle quilters typically use an array of cooperating double chain stitch sewing elements, one element being a needle that is typically positioned above the material and one element being a looper that is opposite the material from the needle, with the entire arrays of both elements being mechanically linked together to move in unison in two dimensions, relative to the material, parallel to the plane of the material in paths that corresponds to identical patterns of a pattern array. The needles and loopers also operate in unison so that the sets of elements simultaneously form identical series of stitches. A common arrangement of this type of quilting apparatus is to support the panel of multilayered material and feed the material from a web longitudinally relative to the sewing element array and in coordination with the motion and operation of the sewing elements. The sewing element array may be shiftable transversely of the web to provide two dimensional stitching capability of the pattern on a panel length of the web. Alternatively, the array is stationary and rollers that support the web shift transversely relative to the array. Some multi-needle quilters of this type have longitudinally bi-directional web feeding capability which, when synchronized with the transverse shifting of the web or the sewing elements, provides for 360° pattern sewing capability.
The single needle quilters are regarded as preferable for the sewing of a wider range of patterns and particularly more highly decorative patterns. In addition, in single need quilters, the lock stitch is commonly used. Lock stitch machines, with their needle and bobbin arrangement, have been made somewhat able to tolerate or avoid needle deflection problems that can result in a missing of stitches when a needle is deflected. Needle deflection is more of a problem when quilting thick materials and complex patterns that involve many directional changes in the sewing path, particularly where higher sewing speeds are used. The lock stitch also provides equally aesthetically acceptable stitching on both sides of the fabric.
The multi-needle quilters are regarded as preferable for sewing mattress covers. With mattress covers, the less attractive looper side stitch may be confined to the inside of the mattress cover on the backing layer of material that is not visible to the observer. Further, the double chain stitch heads of the multi-needle quilters apply a looper side thread from an external spool, which can accommodate a substantially larger thread supply than can the bobbin of a lock stitch machine. As a result, the lock stitch machine can be run longer before the need arises to replenish the bottom thread supplies. The bobbins of the lock stitch machines require frequent changing, particularly with thick multi-layered materials such as mattress covers which require more thread per stitch. A drawback to the use of double chain stitch machines has been the greater likelihood for stitches to be missed as a result of needle deflection. This is in part because a double chain stitch requires the looper on one side of the material to enter a thread loop in close proximity to the needle that has passed through the material from the other side, which needle itself must pass through a thread loop presented by the looper. Misalignment of the needle and looper due to deflection of the needle can result in the missing of stitches which, in the formation of more highly decorative patterns, is undesirable for not only aesthetic reasons but because it can result in an unraveling of the stitched pattern. Attempts at high speed sewing on mattress covers, where the material is generally very thick and the outer or ticking layer of fabric may be heavy and even of an upholstery-like nature, produce unavoidable needle deflection.
With the increased use of computerized pattern control and the resulting ability to provide a wider variety of quilted patterns, particularly patterns of a high ornamental quality, there has been an increasing demand for an ability to sew, more complex and larger patterns onto the covers of mattresses. To this end, equipment of the prior art such as discussed above has limitations. Accordingly, there remains a need for a capability to stitch more highly ornamental and complex patterns onto mattress covers at high speed.
SUMMARY OF THE INVENTION
An objective of the present invention is to provide a computer controlled pattern quilting method and apparatus that will provide a wide variety of quilted patterns, particularly patterns of a high ornamental quality. A particular objective of the present invention is to provide a quilting method and apparatus employing a single needle quilting head and having the capability of quilting at high speed, particularly on thick materials such as those used for mattress covers.
A further objective of the present invention is to provide a quilting method and apparatus having one or more independently moveable sets of single needle chain stitch quilting heads that will stitch at high speeds, particularly on thick materials. A particular objective of the present invention is to provide such a quilting apparatus and method that does not suffer adversely from needle deflection.
According to the principles of the present invention, a quilting machine is provided with at least one set of chain stitch quilting heads that are independently moveable relative to each other and relative to the material being quilted. The machine is preferably web fed and its method of use preferably includes 360° stitching onto material webs of thicknesses typical of those used for mattress covers. In accordance with the preferred embodiment of the invention, a single-needle double chain stitch quilting method and apparatus are provided with independently operable servo driven quilting heads that are each independently moveable relative to the material being quilted. The heads are preferably also independently movable relative to each other in at least one direction, preferably the transverse direction, and the operation of each of the heads is preferably also independent to allow for effective control of the cooperating positions of the needle and looper relative to each other. In the preferred and illustrated embodiment, the needle and looper heads are independently moved transversely to permit adjustment of the cooperating positions of the needle and looper in the transverse direction and the cycles of the needle and looper heads are relatively phased to allow adjustment of the cooperating positions of the needle and looper in the longitudinal direction.
The relative movements and operation of the heads are brought about by computer controlled servos that move and drive the heads so as to maintain the proper cooperative relationship between the needle and looper in accordance with whatever needle deflection takes place. The needle deflection is preferably determined in advance by empirical measurements and data is stored in memory in a programmable microprocessor-based controller of the quilting machine. The stored measurements may be in the form of a look-up table or sets of formula, constants and/or parameters from which needle deflection compensation signals can be supplied to affect the operation of servo motors driving and moving the heads relative to each other and to the material being quilted. Preferably also, the stored empirical data include alternative data that will provide needle deflection compensation for different conditions, such as different materials and fabrics, needles that differ in size or stiffness, varying stitch speeds and stitch sizes, and or other variables that can have an effect on the amount and direction of needle deflection that is expected to occur or does occur.
In accordance with the preferred embodiment of the invention, a quilting machine is provided with web supplies of the various layers of a mattress cover, which webs are brought together in the form of a multiple layered web and fed onto a machine frame, preferably in a horizontal plane. The frame preferably includes a plural belt conveyor that supports the web and aids in the advancement of the web onto the frame. A pair of side edge grippers, which may be in the form of opposed belt grippers, pin chains, clamping finger sets or other side securements, engage the opposite side edges of the web and move the web onto the frame in synchronism with the operation of the belt conveyor. The machine may optionally be provided with a pair of edge stitching heads to at least temporarily stitch together the layers of material of the portion of the web that is advanced onto the frame. Once on the frame, the edge clamps as well as tension rolls at the front and back of the frame tension a portion of the web for quilting.
The quilting is performed by a pair of heads that are each mounted to a bridge structure that is moveable longitudinally on the frame. The bridge is moveable on the frame by a computer controlled servo motor that positions the set of heads in accordance with the pattern to be stitched. Each of the heads is mounted on the bridge so as to be independently transversely moveable. Each head, including an upper needle head and a lower looper head, is provided with a servo motor drive that drives the respective head through its stitching cycle. The two head drive servo motors are operated in synchronism under computer control to sew series of double chain stitches in the fabric. Each head is mounted to the bridge on a linear servo motor that independently positions the head transversely on the frame under the control of the programmed controller of the machine in accordance with the pattern to be stitched.
Needle deflection is accommodated in one of, and preferably both of, two ways. First, needle deflection is accommodated by providing either a table of correction values, or preferably a correction formula based on several empirical constants, and a program in a memory accessible by a microprocessor of the controller in response to which the controller may vary control signals to the servos to control the positions of the heads relative to each other and the relative operational phases of the heads in a way that will compensate for whatever needle deflection is likely to occur. Second, needle deflection is accommodated by sensing certain machine conditions, such as speed, load or power demand or torque angle of servo motors, needle or looper position, or some other relevant machine condition. The sensing may be provided by reading data already present in the controller, by reading control signals being sent to machine servos and other drive elements or by monitoring various sensors separately provided on the machine to sense machine element status or the properties or states or the material or of the thread.
Preferably, transverse deflection of the needle is provided by differently driving the heads transversely so that the looper and needle align whether or not the needle is deflected transversely. Preferably also, longitudinal deflection of the needle is provided by controlling the relative phases of the head drive servos so that the needle and looper engage at the proper time in the cycle whether or not the needle is deflected longitudinally.
The present invention provides for the high speed quilting of patterns on a web of thick fabric of the type of which mattress covers are made. A double chain stitch is sewn without the stitch quality being adversely affected by needle deflection, because servos drive the heads to provide for precise relative positioning. As a result, large spools of lower thread may be provided, eliminating the need to replenish bobbin thread supplies as would be the case with lock stitch machines. Overall higher operating speed and throughput is obtained.
These and other objects of the present invention will be more readily apparent from the following detailed description of the drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a web-fed mattress cover quilting machine embodying principles of the present invention.
FIG. 2 is a side elevational view of the machine of FIG. 1.
FIG. 3 is a diagrammatic perspective view of the sewing heads of the machine of FIG. 1.
FIG. 4 is a diagrammatic representation of the control system of the machine FIG. 1.
FIGS. 5-5C are sequences of diagrams representing needle deflection problems that can occur in the high speed chain stitch quilting of thick fabrics.
FIGS. 6-6C are sequences of diagrams representing needle deflection compensation in accordance with principles of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1 and 2 illustrate a quilting machine 10 having a stationary frame 11 with a longitudinal extent represented by arrow 12 and a transverse extent represented by arrow 13. The machine 10 has a front end 14 into which is advanced a web 15 of multi-layered material that includes a facing material layer 16, a backing material layer 17 and a filler layer 18. The machine 10 also has a back end from which quilted multilayered material is advanced to a take-up or panel cutting section (not shown).
On the frame 11 is mounted a conveyor table 20 that includes a set of longitudinally extending belts 22 supported on a set of transverse rollers 23 journaled to the frame 11 to rotate thereon under the power of a drive motor 24. The motor 24 drives the belts 22 to advance the unquilted web 15 onto the frame 11 at the front end 14 thereof and to advance a quilted portion of the web 15 from the frame 11 to the take-up section at the back end 19 of the machine 10. The belts 22 support a panel of the web 15 in a horizontal quilting plane during quilting. The machine 10 also has a right side 25 and a left side 26, along each of which is mounted a side securement 27 in the form of a pair of opposed conveyor clamp belt or chain loops 28 that operate as a set of edge clamps to grip the edges of the web 15 to assist the feed of the web 15 onto and off of the frame 11 and to apply transverse tension to the web 15 in the quilting plane while a panel of the web 15 is being quilted. The securements 27 may be in the form of a series of gripping finger sets that are spaced along one of the loops 28 of the securements 27. Preferably, however, the securements 27 are each in the form of a pin chain having a plurality of pins on one of the clamp loops 28 that penetrate the web 15 and extend into holes in the other of the clamp loops 28 of the respective pair. A pair of edge stitching heads 29 is also provided, one forward of each of the side securements 27 to temporarily stitch the layers 16-18 of the web 15 together for quilting. Immediately upstream of each of the stitching heads 29 is an edge slitter for trimming excess material to the outside of the edge stitch formed by the stitching heads 29. The loops 28 are linked to move in unison with the belts 22, which are driven by the drive motor 24 on the frame 11.
The machine 10 has a sewing head bridge 30 mounted thereon that extends transversely across the frame 11 and is supported at each side of the frame 11 on a carriage 41. The bridge 30 and carriages 41 are each mounted to move longitudinally on the frame 11 on a pair of tracks 31 on each side of the frame 11. The bridge is driven longitudinally on the tracks 31 by a bridge drive servo motor 32, mounted on the frame 11, which is responsive to signals from a machine controller 60 (FIG. 4).
The bridge 30 has a pair of transverse rails extending from one side of the frame 11 to the other, including an upper rail 33 and a lower rail 34. On the upper rail 33 is mounted an upper quilting head 35 that includes a needle 36 and a needle drive servo motor 37 (FIG. 3), which reciprocally drives the needle in a sewing cycle in response to signals from the machine controller 60. On the lower rail 34 is mounted a lower quilting head 38 that includes a looper 39 and a looper drive servo motor 40 (FIG. 3), which rocks the looper 39 in an arc in a sewing cycle, in synchronism with the motion of the needle 36 in a relationship responsive to separate signals from the machine controller 60.
The upper quilting head 35 is moveable transversely on the upper rail 33 by a linear servo motor 43 in response to signals from the controller 60, while the lower quilting head 38 is also moveable transversely on the lower rail 34 by a linear servo motor 44 in response to signals from the controller 60 independently of the upper head 35. Both of the linear servo motors 43 and 44 are preferably of the iron core type, such as the Ironcore Series of motors manufactured by Koll Morgen Motion Technologies Group of Commack, N.Y.
The bridge 30 carries a set of three idler rollers 46 that move longitudinally on the frame 11 with the bridge 30. The rollers 46 direct the belts 22 downwardly in a loop 47 below the lower rail 34 and lower quilting head 38 to permit the lower quilting head 38 to pass between the belts 22 and the web 15. The loop 47 moves with the bridge 30 and remains aligned with the bridge 30 directly below the lower quilting head 38.
The interconnection of controller 60 with the servos 32, 37, 38, 43 and 44 is diagrammatically illustrated in FIG. 4. The controller 60 includes a CPU or microprocessor 61 and a servo driver module 62. The servo driver module 62 has outputs on which signals are communicated for driving the servos 32, 37, 38, 43 and 44 and has inputs for receiving feedback signals from the servos 32, 37, 38, 43 and 44 to maintain the servos 32, 37, 38, 43 and 44 at positions calculated by CPU 61. The controller 60 also includes a non-volatile memory module 64 that includes a pattern implementation program 65, a needle deflection compensation program 66 and deflection compensation data 67, that may include lookup tables or stored constants or coefficients for use by a compensation formula in the compensation program 66. The controller 60 also has outputs to other components of the machine 10, including the web feed motors 24, the edge stitch units 29 and other machine motors and actuators not relevant to the present invention.
The controller 60 moves the bridge 30 by driving the bridge drive servo 32, and moves the linear servos 43 and 44 to move the quilting heads 35 and 38 in unison in accordance with the stitching pattern provided by the pattern program 65. These movements are carried out in coordination with the driving of the needle drive servo 37 and looper drive servo 40 to stitch patterns with stitches of controlled lengths.
In addition to the programed stitching of the patterns in accordance with the program 65, the CPU 61 modifies signals sent to the drivers 62 by differentially driving the transverse linear servos 43 and 44 to offset the needle 36 and the looper 39 transversely by a distance of preferably plus or minus approximately 0.1 inches, to an accuracy of preferably approximately 0.001 inches. The offset is determined by the CPU 61 in response to a deflection compensation program 66 and empirical data in deflection tables 67 in an amount necessary to precisely compensate for the transverse deflection of the needle 36 that is expected to occur.
Further, in accordance with the program 65, the CPU 61 also modifies signals sent to the drivers 62 by differentially driving the looper drive servo 40 so as to advance or retard the phase of the looper 39 relative to the needle 36 to longitudinally offset the loop take positions of the needle 36 and the looper 39 a phase angle of preferably plus or minus approximately 2.5° to a minimum accuracy of preferably approximately 0.25°. The offset is determined by the CPU 61 in response to a deflection compensation program 66 and empirical data in deflection tables 67 in an amount necessary to precisely compensate for the longitudinal deflection of the needle 36 that is expected to occur.
FIGS. 5-5C diagrammatically illustrates in front view a series showing how the needle 36 might deflect in transverse direction. In FIG. 5, the needle 36 is shown as it begins to pierce the web 15 in the downward part of its cycle in a portion of a pattern at which the web 15 is moving transversely relative to the needle 36, as represented by the arrows 71. At this point in the cycle, the needle 36 lies on a vertical centerline 72 of the upper head 35, which is the line of normal alignment of the needle 36 and the looper 39 that would, if the needle 36 were to remain in the plane 72, bring the needle 36 into contact with the looper 39 below the web 15. By the time the needle 36 has reached the bottom extent in its cycle, as illustrated in FIG. 5A, the relative motion of the needle 36 relative to web 15 results in a bending of the needle 36 to the right in the figure, which moves the tip of the needle 36 away from the line 72 and out of alignment with the path of the looper 39. At this point, the looper 39 is in a retracted position moving forward in a path that is supposed to pass between the needle 36 and top thread 74 that runs through the eye 70 of the needle 36. As the needle 36 ascends, as is illustrated in FIG. 5B, the needle 36 moves to a plane through which the looper 39 is moving forwardly and at which the looper 39 is supposed to pass between the needle 36 and top thread 74. However, due to the deflection of the needle 36 to the right caused by the continued motion of the web 15 relative to the centerline 72 of the upper head 35, the looper 39 misses the thread 74.
In accordance with certain embodiments of the present invention, under the conditions illustrated, the CPU 61 recognizes the needle deflection condition and determines the direction and amount of transverse deflection of the needle 36, then retrieves information 67 stored in the memory 64 and calculates the amount of compensation necessary to position the looper 39 so as to insure that the looper 39 passes between the needle 36 and the top thread 74. This amount of transverse compensation is represented by the dimension t in FIG. 5C. Movement of the lower head 38 relative to the normal position of the upper head 35 places the looper 39 in position 39a in a vertical line 72a, displaced a distance t from the line 72, that passes through the proper point for the looper 39 to pass between the needle 36 and the top thread 74.
Preferably, the CPU makes corrections by generating the main component of the signal to the servos 43 and 44 in accordance with the pattern program 65. Then, this signal is modified by the substantially smaller deflection compensation signal read by the program 66 from the table 67 that modifies one or both of the signals to the servos 43 and 44. Preferably, the modification is made to the looper head positioning servo 44.
The longitudinal correction for needle compensation works in a somewhat different manner. In FIGS. 6-6C there is diagrammatically illustrated a series of side views showing how the needle 36 can deflect in the longitudinal direction. In FIG. 6, the needle 36 is shown as it begins to pierce the web 15 in the downward part of its cycle in a portion of a pattern at which the needle 36 is moving longitudinally relative to the web 15, as represented by the arrows 75. At this point in the cycle, the needle 36 lies in a vertical plane 76 that contains the vertical centerline of the upper head 35, which is the line of normal alignment of the needle 36 with the looper 39 and the line that contains the position at which the looper 39 would, if the needle 36 were to remain in the plane 76, bring the needle 36 into contact with the looper 39 below the web 15 and pass between the needle 36 and the top thread 74. By the time the needle 36 has reached the lowest point in its cycle, as illustrated in FIG. 6A, the relative motion of the needle 36 relative to the web 15 results in a bending of the needle 36 forward (to the right in FIG. 6A), which moves the needle 36 away from the plane 76 of the normal intercept point of the needle 36 with the looper 39. At this time, the looper 39 is in a retracted position moving forward in a path that is supposed to pass between the needle 36 and top thread 74 that runs through the eye 70 of the needle 36. As the needle 36 ascends, as is illustrated in FIG. 6B, the needle 36 moves to adjacent the point through which the looper 39 is moving forwardly and at which the looper 39 is intended to pass between the needle 36 and top thread 74. However, due to the deflection of the needle 36 to the right (forward) caused by the continued motion of the upper head 35 relative to the web 15, the looper 39 misses the thread 74.
In accordance with certain embodiments of the present invention, under the conditions illustrated, the CPU 61 recognizes the condition and determines the longitudinal deflection of the needle 36, then retrieves information 67 stored in the memory 64 and calculates of the amount of compensation necessary to position of the looper 39 so as to insure that the looper 39 passes between the needle 36 and the top thread 74. This amount of longitudinal compensation is in the form of an angular adjustment or relative phase angle in the drive cycles of the heads 35 and 38 as controlled by the operation of the servos 37 and 40. The phase difference is represented by the angle φ in FIG. 6C. Phasing of the looper drive 40 relative to the normal looper angle places the looper 39 in position 39a in a plane 76a that passes through the proper point for the looper 39 to pass between the needle 36 and the top thread 74.
Preferably, the CPU makes corrections by generating the main component of the signal to the servos 37 and 40 in accordance with the pattern program 65. Then, this signal is modified by the substantially smaller deflection compensation signal read by the program 66 from the table 67 that modifies one or both of the signals from the controller 60 to the servos 37 and 40. Preferably, the compensation is made to the looper drive servo 40.
Concepts of the invention may also be applied to alter the transverse motion of the upper head 35 by operation of the servo 43 or to alter the longitudinal motion of both heads 35 and 38 by affecting movement of the bridge 30 by servo 32 so as to decrease, at least in part, the amount of needle deflection. This, in effect, produces an indexing motion to the quilting heads 35 and 38 relative to the web 15, which is not fully practical in high speed quilting processes.
Details of machines 10 of the above described embodiment that are known in the art can be found in U.S. patent application Ser. No. 08/497,727, filed Jun. 30, 1995 entitled Quilting Method and Apparatus, which relates to single needle quilters but of the lock stitch type, and in U.S. Pat. No. 5,154,130, which relates to web-fed chain stitch quilters but of ganged multi-needle type, both of which are assigned to the assignee of the present invention and are hereby expressly incorporated by reference herein.
More than one set of independently driven heads may be supported on the frame 11. For example, two sets of heads 35,38 may be supported for transverse movement on the bridge 30, each separately controllable in the transverse direction and each separately drivable to stitch patterns on the web 15, with separate control thereof to compensate separately for the needle deflection that would occur at each head.
Those skilled in the art will appreciate that various changes and additions may be made to the embodiments described above without departing from the principles of the present invention. | A quilting machine is provided having at least one set of single needle stitch forming elements for forming chain stitched patterns on a thick multilayered material such as a mattress cover. The machine is preferably web fed, with a panel of the continuous web being clamped and held stationary on a frame. The elements include a needle and a looper mounted on separate heads that are independently moveable transversely on a bridge, which is moveable longitudinally on the frame. The bridge is longitudinally moved by a servo and the heads are transversely moved on the bridge by separate servos. Each head is driven by a separate servo. A controller drives the servos to chain stitch patterns and differentially moves the heads transversely to account for transverse needle deflection. The drives of the needle and looper are phased to compensate for longitudinal needle deflection. The controller stores empirically determined data and responds to control signals or sensors to determine deflection and calculate the needle deflection compensation from which it generates deflection compensation signals to drive the servos. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to solvent casting, which consists of dissolving one or more synthetic resins in an organic solvent, casting the solution onto a suitable substrate, removing the solvent whereby a film is formed on the carrier, and stripping the film from the carrier. Normally the film is wound into rolls.
2. Description of the Prior Art
Solution-cast polymeric films have been used for decades. The most familiar of them are the high quality films used in photographic films. Cellulose ester photographic film base is best known for its dimensional stability and high clarity.
There are many other processes for the formation of films. Calendering, extrusion plastisol cast systems, and organosol cast systems are the most common. However, solvent casting is the only method that can provide a film which has excellent dimensional stability as well as freedom from pinholes, gels and imperfections. Due to the very low heat history which is inherent in the solvent casting processing, it provides an extended service life to the film.
The solution cast process offers several unique features which conventional fusion processes lack. Extrusion and calendering are processes which melt the polymer and shape the plastic prior to freezing. Plastisol and organosol casting processes involve the melting of the polymer in a plasticizer matrix, after which the solvent action of the plasticizer forms a film. In solvent casting, film formation depends solubility, not melting. Thus, a wide range of polymeric alloys can be produced by solvent casting. Because the flowability to form a film is provided by the solvent, a pure resin film can be manufactured without adulteration by heat, stabilizers, plasticizers or lubricants. Only additives which are beneficial to the finished product need to be incorporated with the polymer.
There are disadvantages to solvent casting when compared to other film-forming methods, such as extrusion. Solvent casting obviously requires a solvent, which is in most cases quite expensive. This necessitates a complex solvent vapor recovery and rehabilitation system. Moreover, exposure of personnel to certain solvents is undesirable, and this requires a system that is closed to the atmosphere, especially when temperatures above the boiling point of the solvent are used.
Attempts have been made to solvent cast acrylic films without the use of additives or release coatings applied to the casting substrate. However, these attempts have heretofore been unsuccessful because the films produced were not strippable: the films adhered to the substrate or carrier after the removal of the solvent. Accordingly, the prior art regards acrylic films as not suitable for solvent casting. Current acrylic films are produced primarily by extrusion with its inherent disadvantages. The superior properties of the present films cannot be duplicated in films prepared by other methods, such as extrusion.
SUMMARY OF THE INVENTION
It has been unexpectedly discovered that solvent cast acrylic films can be produced provided that the polymers used to produce the films are restricted to a unique group of acrylic polymers hereinafter described as the polymer system. The films thus produced can easily be stripped from the substrate or carrier.
The acrylic films of the present invention have superior properties. They are free of gels and imperfections, including pinholes. The films of the present invention have excellent dimensinal stability and excellent gauge uniformity. They possess high clarity and high gloss, and resist ultraviolet light transmission. These films can be printed and metalized. They can also be laminated to other plastics or substrates (including metals, woods, papers, foils and glass) by means of heat or adhesives. The resulting surfaced substrates show excellent exterior weatherability.
The acrylic films of the present invention are produced by a solvent casting method. A polymer system and a suitable organic solvent are mixed to form a solution. The solution is cast onto a substrate. The solvent is removed thereby leaving the film on the substrate. The film is then stripped from the substrate.
The polymer system comprises at least one polymer prepared by polymerizing monomers of the general formula (I): ##STR2## wherein: R 1 is hydrogen or methyl; and R 2 is straight or branched alkyl of about 1-20 carbon atoms, preferably about 1-8 carbon atoms, more preferably 1-4 carbon atoms, and most preferably 1-2 carbon atoms.
The polymers are homopolymers, mixed copolymers, and graft copolymers. They may be cross-linked.
The polymers have the following properties:
Total Elongation (%) of about 120-250, preferably about 150-210, and more preferably about 170-190;
Tear Resistance of about 4.5-12.5 g/mil (which is about 177-492 mg/micron), preferably 6-10 g/mil (which is about 236-394 mg/micron), and more preferably about 8-9 g/mil (which is about 315-354 mg/micron);
Tensile Strength of about 4500-5000 lbs/in 2 (about 317-387 kg/cm 2 ), preferably about 4800-5200 lbs/in 2 (about 338-366 kg/cm 2 ), and more preferably about 4900-5100 lbs/in 2 (about 345-359 kg/cm 2 );
Molecular Weight (amu) of about 250,000-500,000, preferably about 300,000-400,000, and more preferably about 325,000-375,000;
Acid Content (%) of about 0.0-5.0, preferably about 0.0-2.0, and more preferably about 0.0-0.9;
Tucon hardness (Knoop No.) of about 6-12, preferably of about 7-11, and more preferably of about 8-10; and
The polymer is substantially free of reactive groups, such as hydroxy groups.
The acrylic film has Total Elongation, Tensile Strength, Tear Resistance, Acid Content and Tucon hardness in the aforesaid ranges, and is substantially free of reactive groups, such as hydroxy groups. The residual solvent in the film is (weight %) about 0-3, preferably about 0-2, and more preferably about 0.1-1.0. The film has dimensional stability (% shrinkage at about 130° C. for films of 0.5-5.0 mils, which is about 13-127 microns) of about 0-3, preferably of about 0-2, and more preferably of about 0.1-1.0. The thickness of the films is generally about 0.5-5.0 mils (which is about 13-127 microns), preferably about 0.75-3.0 mils (about 19-76 microns), and more preferably about 1.0-2.5 mils (which is about 25-63 microns). The films have excellent flexibility and extensibility. They are completely free of pinholes, gels and imperfections. The films have excellent weatherability.
Unless the contrary is expressely noted, any reference to a polymer in this description also includes a mixture of polymers having the same properties and produced from the same group of monomers as the polymer, provided that all polymers of the mixture are substantially miscible in each other in the solvent.
DETAILED DESCRIPTION OF THE INVENTION
In the present invention the resin to be cast is a polymer system. The polymer system may comprise a single polymer, or a plurality of polymers.
The polymers are prepared by polymerizing monomers of the general formula (I), more fully described above in the Summary of the Invention. Processes of polymerization are well known to the art. In this regard, the disclosures of the following U.S. Patents are hereby incorporated by reference, U.S. Pat. Nos.: 2,992,203; 3,454,516; 3,502,604; 3,804,925; 4,052,525; and 4,173,600.
The polymers used to form the films of the present invention are prepared by polymerizing alkyl acrylates and alkyl methacrylates (with reference to formula (I), R 1 is hydrogen and methyl, respectively). Preferred monomers include: alkyl acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, isobutyl acrylate, lauryl acrylate, and 2-ethylhexylacrylate; and alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, isobutyl methacrylate, lauryl methacrylate, and 2-ethylhexylmethacrylate.
In a first embodiment of the present invention, the polymer system comprises a graft copolymer prepared by polymerizing monomers of the general formula (I), as more fully described in the summary of the invention. It is preferred that each section of the graft copolymer be comprised of monomers of at least one alkyl acrylate and monomers of at least one alkyl methacrylate. It is preferred that the sections of the graft copolymer each be comprised of the same alkyl acrylate and alkyl methacrylate monomers, but that the sections differ in the relative amounts of these monomers.
In a second embodiment of the present invention, the polymer system comprises a graft copolymer of three sections: section (A), which is about 5-35%, preferably 25-30%, of the polymer by weight (all subsequent % compositions are by weight, unless the contary is expressly noted), and is comprised of about 80-100%, preferably about 90-100% of an alkyl (of 1-8 carbons) acrylate monomer or monomers, and about 0-20% preferably about 0-10%, of an alkyl (of 1-12 carbons) methacrylate monomer or monomers and may be crosslinked; section (B), which is about 1-70%, preferably 5-50%, of the polymer, and is comprised of about 10-60%, preferably about 20-60%, of an alkyl (of 1-8 carbons) acrylate monomer or monomers, and about 40-90%, preferably about 40-80%, of an alkyl (of 1-4 carbons) methacrylate monomer or monomers, and about 0-20% of an alkyl (1-12 carbons) methacrylate monomer or monomers; and Section (C), which is the remainder of the polymer, and is comprised of about 60-100%, preferably about 85-100%, of an alkyl (of 1-4 carbons) methacrylate monomer or monomers, and about 0-40%, preferably about 0-15%, of an alkyl (of 1-12 carbons) methacrylate monomer or monomers.
In a third embodiment of the present invention, the polymer system comprises a graft copolymer of four sections (or layers): section (A) which is about 5-35% of the polymer, and comprises about 51-100 parts by weight (all subsequent parts are by weight unless the contrary is expressly noted) of an alkyl (of 1-4 carbons) methacrylate monomer or monomers, about 0-49 parts of an alkyl (1-8 carbons) acrylate monomer or monomers, about 0-10 parts of a polyfunctional monomer, and about 0.1-5 parts of a graftlinking agent; section (B), which is about 5-45% of the polymer, and comprises about 80-120 parts of an alkyl (1-8 carbons) acrylate monomer or monomers, about 1-10 parts of a polyfunctional monomer, and about 0.1-5 parts of a graftlinking agent; section (C), which is about 5-35% of the polymer, and comprises about 10-90 parts of an alkyl (of 1-4 carbons) methacrylate monomer or monomers, about 90-100 parts of an alkyl (of 1-8 carbons) acrylate monomer or monomers, about 0-10 parts of a polyfunctional monomer, and about 0.1-5 parts of a graftlinking agent; and section (D), which is about 10-80% of the polymer, and comprises 51-100 parts of an alkyl (of 1-4 carbons) methacrylate monomer or monomers, and about 0-49 parts of an alkyl (of 1-8 carbons) acrylate monomer or monomers. Suitable graftlinking agents include allyl, methallyl, and crotyl esters of copolymerizable alpha,beta-unsaturated monocarboxylic or dicarboxylic acids; triallyl cyanurate; and triallyl isocyannurate in an amount of 0.1 to 5 parts by weight. The allyl esters include those of acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid. The preferred esters are those of acrylic acid and methacrylic acid. Of these, allyl methacrylate is especially effective. The graftlinking agent is used in an amount of 0.1 to 5, preferably 0.5 to 2, parts by weight per 100 parts by weight of the respective section. The polyfunctional monomers are copolymerizable and include preferably ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, and propylene glycol dimethacrylate; divinylbenzene and alkylene glycol diacrylates. The graft copolymer may be obtained without using such a polyfunctional monomer so long as an allyl ester is present. Optionally, the graft copolymer may comprise five sections (A);(C);(B);(C); and (D).
In a fourth embodiment of the present invention, the polymer system comprises a mixed copolymer which comprises: about 10-60%, preferably 30-50%, and more preferably 35-45% of alkyl acrylate monomers of formula (I); and about 40-90%, preferably 50-70%, and more preferably 55-65% of alkyl methacrylate monomers of formula (I). Preferably, the mixed copolymer comprises only one type of alkyl acrylate monomer of formula (I), and only one type of alkyl methacrylate monomer of formula (I). However, when the mixed copolymer comprises a plurality of types of alkyl acrylate monomers of formula (I), it is preferred that the alkyl methacrlate monomers of formula (I) comprise the same alkyl groups (to illustrate, if methyl acrylate and ethyl acrylate are the acrylate monomers, then it is preferred that methyl methacrylate and ethyl methacrylate are the methacrylate monomers).
In the fifth and most preferred embodiment of the present invention, the polymer system comprises a mixture of two mixed copolymers: about 50-99%, preferably 70-99%, more preferably 80-95%, and most preferably about 90% of Polymer A; and about 1-50%, preferably 1-30%, more preferably 5-20%, and most preferably about 10% of Polymer B. Polymers A and B are each mixed copolymers prepared by polymerizing monomers of formula (I). It is preferred that Polymers A and B have at least one monomer in common, and preferably all monomers in common. It is preferred that Polymers A and B each comprise one alkyl acrylate and one alkyl methacrylate. It is critical that polymers A and B are miscible in each other in the organic solvent used to cast the film.
Polymer A is the "soft" polymer of the polymer system and Polymer B is the "hard" polymer of the system. It is noted that acrylate monomers are generally "softer" than methacrylate monomers, and that as the number of carbons in the alkyl group increases, the "softness" of the acrylate or methacrylate increases.
Polymer A has the properties of the polymers of the present invention described in the Summary of the Invention. In contrast, Polymer B has the following properties: it is prepared by polymerizing monomers of formula (I) above; it has a Total Elongation (%) of about 3-7%; it has a Tensile Strength of about 8,000-10,000 lbs/in 2 (which is about 563-704 kg/cm 2 ); it has a Tear Resistance of 4-6 g/mil (which is about 157-236 mg/micron); Molecuar Weight (amu) of about 90,000-120,000, and preferably about 100,000-110,000; Acid Content (%) of about 0.0-5.0, preferably about 0.0-2.0, and more preferably about 0.0-0.9%; and Tucon hardness (Knoop. No.) of about 12-22, and preferably about 15-19.
Polymer A preferably comprises: about 10-60%, more preferably about 30-50%, and most preferably about 35-45% of alkyl acrylate (R 1 is hydrogen) monomers of formula (I), and more preferably of a single alkyl acrylate monomer of formula (I); and about 40-90%, more preferably about 50-70%, and most preferably 55-65% of alkyl methacrylate (R 1 is methyl) monomers of formula (I), and more preferably of a single alkyl methacrylate monomer of formula (I).
Polymer B preferably comprises about 3-20%, and preferably about 3-10% of alkyl acrylate (R 1 is hydrogen) monomers of formula (I), and preferably of a single alkyl acrylate monomer of formula (I); and about 80-97%, and preferably about 90-97% of alkyl methacrylate (R 1 is methyl) monomers of formula (I), and preferably of a single alkyl methacrylate monomer of formula (I).
In an example of the fifth embodiment of the present invention, Polymer A had a Tensile Strength of 5,000 lbs/in 2 (about 352 kg/cm 2 ), a Total Elongation of 175-185%, and a Tear Resistance of 8.5 g/mil (about 335 mg/micron), and Polymer B had a Tensile Strength of 9000 lbs/in 2 (about 634 kg/cm 2 ), a Total Elongation of 5%, and a Tear Resistance of 5 g/mil (about 197 mg/micron). The resulting film had the superior properties described in the foregoing, and an acid content of about 0.5%.
Obviously, a compatible "hard" polymer, such as Polymer B, could be mixed with any of the polymers of the present invention, including those of the first four embodiments, to form a polymer system. Such compatible "hard" polymers can be used to adjust the softness of the resulting film.
In addition, the present invention includes the incorporation of an incompatible monomer or polymer into the mixture of solvent and polymer system. For example, polyvinylchloride (PVC) in an amount up to about 20% of the weight of the polymer system can be added to the mixture of solvent and polymer system to produce a film having a matte finish.
In the foregoing, Total Elongation was measured according to procedures standard in the art. The pure polymer was solvent cast and the film slit into one inch (about 2.54 cm) strips. An Instron Tensile Testing Machine elongated the strip at about 2 inches (about 5.08 cm) per minute.
In the foregoing, Tensile Strength was measured according to ASTM D 822-67, Method B, reapproved 1970, "Tensile Properties of Thin Plastic Sheeting".
In the foregoing, Tear Resistance was measured according to ASTM D 1938-67, reapproved 1972, "Tear Propogation or Resistance to in Plastic Film and Sheeting by Single Tear Method."
FIG. 1 is a schematic representation of a preferred method and apparatus of the present invention.
Storage containers 1-4 of raw materials are used to store the polymer or polymers, solvent, and additives known to the art, such as ultra-violet light (UV) absorbers.
In a preferred method of the present invention an organic solvent is placed in the mixer 5. The polymer system must be completely soluble in the solvent. Suitable solvents include: Acetone, Aniline, Dimethyl Sulfoxide (DMSO), Benzene, Dimethyl Formamide (DMF), Methyl Ethyl Ketone (MEK), Ethyl Acetate, Ethylene Dichloride, Toluene, and Tetrahydrofuran (THF). However, the solvent of preference is THF.
All components of the film are added to the solvent in the mixer 5. Mixing is a batch operation carried out in mixer 5 with agitation provided by a high shear mixing blade 6, eccentrically located in the mixer. If a clear film is desired, it is critical that a true solution of all the components be achieved.
The preferred composition of components charged to the mixer is about 25-50% solids and about 50-75% solvent. After the components have been added to the solvent, mixer 5 is closed and sealed to prevent the escape of solvent vapors. Agitation by blade 6 is begun, and steam from steam source 8 is charged to the mixer steam jacket 7. Assuming THF is used as the solvent, the mixture is preferably heated to about 190°-210° F. (88°-99° C.). As a general rule, the mixture is heated to a temperature above the boiling point of the solvent, but less than a temperature about 100° F. (38° C.) above the boiling point of the solvent. Since THF boils at 152° F. (67° C.) at atmospheric pressure, pressure builds up in mixer 5 as the temperature is increased. If the mixture is at about 200° F. (93° C.), the pressure in the mixer is about 45 lbs/in 2 (3.2 kg/cm 2 ). Preferably, the mixture is mixed at about 190°-210° F. (88°-99° C.) until the viscosity of the solution is about 2,000-3,000 centipoise, more preferably 2,200-2,800 centipoise, and most preferably about 2,500 centipoise. In order to measure the viscosity of the mixture, it is preferred that mixer 5 is provided pipes 9 and 12, viscosity meter 10, and three way valve 11. When three way valve is in the first open position, mixture is pumped by suitable means from the bottom of mixer 5 through pipe 9, which carries it through meter 10, through valve 11 and into pipe 12, thereby returning it to the top of mixer 5. The mixture is allowed to flow through this closed loop continuously, and the current viscosity of the mixture is read on meter 10.
When desired viscosity is reached valve 11 is moved to the second open position, and the mixture is pumped by suitable means from the bottom of mixer 5, through pipe 9, valve 11, pipe 13, filter 14, and pipe 15 into the top of holding tank 16. This system is closed to the atmosphere to prevent the escape of solvent in the vapor or liquid state.
Filter 14 is preferably a plate frame filter to remove solution contaminants and to strain out any coarse undissolved ingredients.
It is preferred that mixer 5 not be pumped dry while in communication with holding tank 16 as this would introduce a large number of additional air or gas bubbles into the mixture. Bubbles are undesirable as they cause pinholes in the films. Once mixer 5 is substantially empty, valve 11 is closed and mixer 5 is cooled until it is ready to accept the next batch.
The mixture in holding tank 16 is isolated by closing appropriate valves (not shown). As the mixture cools to a temperature below the boiling point of the solvent, the viscosity obviously increases. Assuming the preferred solvent (THF) is being used, when the temperature of the mixture reaches about 130°-150° F. (54°-66° C.), the pressure in holding tank 16 is atmospheric pressure. At this point, bubbles in the mixture begin to surface. The mixture is allowed to sit until such time as substantially all bubbles have surfaced. In a preferred embodiment of the present invention, it requires about 2-4 hours before all bubbles have surfaced. Thus, the mixture has been degassed.
After the mixture has been degassed, it is then pumped by suitable means from the bottom of holding tank 16 (at atmospheric pressure but closed to the atmosphere) through pipe 17 and into casting tank 18. Holding tank 16 is never pumped dry as this would introduce gas bubbles into the mixture. There is always a sufficinet amount of degassed mixture left in holding tank 16 so as to be absolutely certain that no bubbles enter pipe 17.
The level of degassed mixture in casting tank 18 is never allowed to drop below the terminus of pipe 17 which is closely adjacent the bottom of casting tank 18. This prevents the formation of bubbles in the mixture. If the mixture exited from pipe 17 and dropped to the surface of the remaining mixture in casting tank 18, bubbles would be formed. As stated above, bubbles in the mixture cause pinholes in the film.
Mixture from casting tank 18 is pumped by suitable means through filter 19 to die 21. Filter 19 is preferably a plate frame filter. The mixture (at a temperature below its boiling point) is deposited on the casting surface 23 by die 21. As the casting solution leaves die 21, the solution is exposed to air for the first time.
While a die 21 is illustrated, it is not critical. The spreading of the mixture on the casting surface may be done with a doctor blade, rolling spreader bar or any of several configurations of flat sheeting extrusion dies.
The casting surface (or substrate) can be an endless belt of highly polished stainless steel, copper, or silicone rubber. The casting surface may also be an endless belt of any material coated with another insoluble polymeric material or release paper. Regardless of the construction, the casting surface may be textured so as to form a matte finish, or a glossy highly polished one. Alternatively, a casting drum may be used in place of the endless belt. Laboratory tests are frequently carried out using glass or stainless steel plates as a substrate. However, plates are not suitable for continuous casting and are therefore not used in production runs.
In one preferred embodiment, casting surface 23 is a continuous stainless steel belt supported by pulleys 24 and 25, which are driven to rotate in the direction shown, thereby providing a moving casting belt 23, in bandcaster 20. The band speed is generally about 40-100 feet (12-30 m) per minute, but depends on a number of factors, such as the viscosity and temperature of the casting mixture.
Bandcaster 20 is provided with as series of heating zones 26, 27, 28, 29, and 30, at least one cooling zone 31, and a solvent vapor recovery system (not shown). Generally, the temperature in zones 26, 27 28, 29 and 30 increases so that the film is gradually heated. This causes the solvent to vaporize, thereby removing it from the mixture on belt 23 and forming the film. However, it is critical that the temperature of the film be kept sufficiently below the boiling point of the solvent so as to prevent the formation of bubbles of solvent vapor in the film, because such bubbles would cause pinholes in the film. As the film cools, it becomes more resistant to bubble formation. The temperatures of the zones depend on a variety of factors: thickness of film; temperature of casting solution; composition of film; solvent; belt speed; and so forth. At least one zone 31 is provided to cool the film before it is stripped from the casting belt.
After the film 32 is stripped from belt 23, it may be wound directly onto a roll (not shown). Alternatively, it is dried in a festoon drier 35 and wound onto roll 36. Festoon drier 35 is provided with a plurality of rollers, an air source (not shown), a heat source (not shown), and a solvent recovery system (not shown). As the film travels over the plurality of rollers in festoon drier 35, both sides of the film are exposed to the air. This allows increased rate of drying when compared to drying on casting belt 23, when only one side of the film is exposed to the air. After the film leaves festoon drier 35, it is wound on roller 36.
In the foregoing, both English and metric units of measurement are given. Generally speaking, applicant carried out the relevant tests and experiments using English units, and then these units were converted to metric units for purposes of the present application. For example, the tear resistance was measured in g/mil, and converted to mg/micron. Accordingly, if there is a disagreement between the English and metric units, the English units take precedence. | Acrylic films having superior properties are produced by casting a solution comprising an organic solvent and a polymer system of one or more completely polymerized acrylic polymers onto a carrier, removing the solvent thereby forming the film on the carrier, and stripping the film from the carrier.
The polymer system comprises at least one polymer prepared by polymerizing monomers of the general formula (I): ##STR1## wherein: R 1 is hydrogen or methyl; and R 2 is straight branched alkyl of about 1-20 carbon atoms, preferably about 1-8 carbon atoms, more preferably 1-4 carbon atoms, and most preferably 1-2 carbon atoms.
The polymers are homopolymers, mixed copolymers, and graft copolymers. They may be cross-linked. | 8 |
FIELD OF THE INVENTION
The present invention relates to a method and a machine for continuously dyeing textile yarns.
PRIOR ART
The Applicant Company described, in its French Patent 89 10277 of 26 Jul. 1989, a machine for continuously dyeing textile yarns, in which these yarns travel continuously in front of a succession of stations for applying dyes of different colors, each station applying a succession of spots onto the yarns, so that each yarn includes a succession of spots forming a pattern extending over a certain length of the yarn and which is continually repeated.
In this machine, each application station comprises a dye-spraying turbine rotationally driven about an axis which is parallel to the direction of travel of the yarns, each turbine having several holes for the passage of the dye which are suitable for spraying a succession of spots onto the yarns.
In this embodiment, the set of turbines is connected by a common shaft driven by a single electric motor, so that all the turbines rotate at the same speed.
There is thus obtained on the yarns a succession of spots with a given order of colors, forming a pattern extending over a certain length of yarn and which repeats indefinitely and perfectly.
The textile yarns thus obtained are used particularly for manufacturing carpets.
The Applicant Company noticed that the perfect repetition of the aforementioned pattern of spots on the yarns was manifested by the presence on the carpets of defects in the form of strips affecting the quality of these carpets.
The object of the present invention is to overcome this drawback.
SUMMARY OF THE INVENTION
The present invention thus relates to a method for continuously dyeing textile yarns, in which these yarns travel continuously in front of a succession of stations for applying dyes of different colors, each station applying a series of spots onto the yarns, so that each yarn includes a succession of spots forming a pattern extending over a certain length of the yarn and which is continually repeated.
According to the invention, this method is one wherein the stations for applying the dye are commanded individually in order to corrupt the repetitiveness of the successive patterns.
This method thus makes it possible to eliminate the defects discussed earlier.
According to a first version of the method, the stations for applying the dye are commanded individually in order to modify the length of the successive patterns.
Thus, the length of the successive patterns will vary slightly from one pattern to another.
This result may be obtained by adjusting the rotational speed of electric motors individually driving the turbines for spraying the dye.
According to a second version of the method, the stations for applying the dye are commanded individually in order to modify the order of the colors of the spots in the successive patterns.
This measure, combined with the previous one, makes it possible to corrupt the repetitive nature of the pattern of the spots of color still further.
This result, like the previous one, may be obtained by commanding sudden variations in the rotational speed of the motors driving the turbines.
According to a third version of the method, the stations for applying the dye are commanded individually in order to form successive patterns which are different from one another owing to the presence or absence of a spot of given color.
According to another aspect of the invention, the machine for continuously dyeing textile yarns comprises a succession of stations for applying dyes of different colors, means for making the textile yarns travel continuously in front of the said application stations, each application station comprising a dye-spraying turbine driven rotationally about an axis which is parallel to the direction of travel of the yarns, each turbine having several holes for the passage of the dye which are suitable for spraying a succession of spots onto the yarns, the set of application stations being suitable for forming on the yarns a pattern of spots extending over a certain length of yarn.
According to the invention, this machine is one wherein the application stations comprise individual command means making it possible to corrupt the perfect repetitiveness of the successive patterns.
Other features and advantages of the invention will emerge further in the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
In the appended drawings given by way of non-limiting examples:
FIG. 1 is a diagrammatic front view of a continuous dyeing machine according to the invention,
FIG. 2 is a sectional view of a turbine of the machine according to the invention,
FIG. 3 is a view of a textile yarn including a series of colored spots obtained by means of a machine in accordance with the invention,
FIG. 4 is a diagram illustrating a first version of the invention and representing the variation in length of a pattern of a succession of spots as a function of time,
FIG. 5 is a diagram also illustrating the first version of the invention and representing the variation in the rotational speed of the turbines as a function of time,
FIG. 6 is a view of the textile yarn obtained after implementing the version illustrated in FIG. 5,
FIG. 7 is a view of the textile yarn obtained after implementing a second version of the invention,
FIG. 7A is the chart of the rotational speeds of the turbines when implementing the second version of the invention combined with the first version,
FIG. 8 is a view of the textile yarn obtained after implementing a third version of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, the machine 10 for continuously dyeing textile yarns includes a frame 11 capped by a casing 12 inside which there is mounted a device 13 for applying a plain dye to a lap of yarns 14, and three stations 15a, 15b, 15c comprising dyeing turbines T 1 , T 2 , T 3 intended to apply discontinuous spots of dyes which are generally not superimposed. It is clearly understood that the number of dyeing turbines intended to apply spots may be other than three, depending on the results which it is desired to obtain. A reservoir of plain dye 13' is associated with the application device 13, and the reservoirs 15'a, 15'b and 15'c are associated with the stations for depositing colored spots.
Such a machine has been described in detail in French Patent 89 10277 in the name of the Applicant Company. Consequently, only the modifications made to this machine will be described in detail here.
FIG. 2 represents one of the dye-spraying turbines T 1 , rotationally driven about an axis X-X' which is parallel to the direction of travel of the yarns 14. The turbine T 1 includes, in the example shown, at its periphery, three holes 16 for the passage of the dye. These holes 16 are suitable for spraying a succession of three spots A 1 , A 2 , A 3 , which are spaced apart and of the same color, onto the yarns 14, as indicated in FIG. 3.
In the example of FIG. 3, the turbine T 2 sprays four spots B 1 , B 2 , B 3 , B 4 of a different color from that of the spots A 1 , A 2 , A 3 onto the yarn 14.
Likewise, the third turbine T 3 sprays three spots C 1 , C 2 , C 3 onto the yarn.
The three turbines T 1 , T 2 , T 3 thus form, on the yarn 14, a pattern of spots extending over a length L of the yarn which depends on the speed of travel of this yarn.
When the three turbines T 1 , T 2 , T 3 rotate at the same speed, as envisaged in the machine described in French Patent 89 10277, the pattern of length L repeats indefinitely with perfect regularity.
In accordance with the invention, the application stations 15a, 15b, 15c of the machine represented in FIG. 1 comprise individual command means making it possible to corrupt the perfect repetitiveness of the successive-patterns.
In the example represented in FIG. 1, the turbines T 1 , T 2 , T 3 are each rotationally driven by an electric motor M 1 , M 2 , M 3 . The rotational speed of each of these motors may be adjusted independently of that of the other motors.
It is thus possible to modify, in a predetermined manner, the length L of the successive patterns so as to corrupt the repetitiveness of the latter.
The speed of the motors M 1 , M 2 , M 3 may consequently be programmed so that the length of the second pattern is longer or shorter than that of the first pattern, and so on.
FIG. 4 represents, by way of example, the variation as a function of time t of the length L of the successive patterns which is obtained by uniformly varying the rotational speed of the turbines T 1 , T 2 , T 3 .
1) In this example, the length increases from a mean value L m up to a maximum value equal to +20% of the value L m , then decreases down to a minimum value equal to -20% of the value L m , then rises again up to the mean value L m .
The duration t 1 of the cycle represented in FIG. 4 corresponds to a large number of successive patterns.
This duration will be chosen depending on the desired result.
The variation in rotational speeds of the motors M 1 , M 2 , M 3 driving the turbines may be commanded by a computer P (see FIG. 1) preprogrammed in a suitable manner.
2) FIG. 5 illustrates the chart of the variation in rotational speed N as a function of time t, for the turbines T 1 , T 2 , T 3 , . . . , which must be adopted when it is desired to obtain this nonrepetitive nature of the successive patterns.
The speed N of the motor of the turbines T 1 , T 2 , T 3 , . . . varies by plus or minus 20% about a mean value Nm, and this speed is different, at a given moment, for the different turbines.
The initial phase shift between the turbines is thus preserved, which makes it possible to avoid superposition of the spots.
In the case represented, the speed of the turbines T 2 , T 3 is, at a given moment, slightly less than that of the turbine T 1 , for example by 20 rpm.
FIG. 6 shows the result obtained.
The top diagram shows the succession of the spots A 1 , B 1 , C 1 which are obtained during a first cycle, with the turbines rotating at nominal speed.
The middle diagram shows the succession of spots A' 1 , B' 1 , C' 1 during a second cycle, with the turbines rotating at a reduced speed.
The bottom diagram shows the succession of spots A" 1 , B" 1 , C" 1 during a third cycle in which the turbines rotate at an increased speed.
According to the second version of the invention, illustrated by FIG. 7, the adjustment of the speeds of the turbines is such that the order of the colors of the spots in the successive patterns is modified by abruptly accelerating or decelerating the speed of one of the turbines.
In the example of FIG. 7, the first pattern (at the top of the figure) comprises a normal succession of spots A 1 , A 2 , A 3 (turbine T 1 ), B 1 , B 2 (turbine T 2 ) and C 1 , C 2 (turbine T 3 ).
In the second pattern (at the bottom of the figure), the rotational speed of the turbine T 2 has been accelerated so that the first spot B 1 sprayed by the turbine T 2 becomes interposed in the succession of spots A 1 , A 2 , A 3 sprayed by the turbine T 1 .
This version of the method may be combined with the previously-described version so as to increase still further the nonrepetitive nature of the successive patterns. The chart of FIG. 7A illustrates this combination.
In a third version of the invention, each turbine T 1 , T 2 , T 3 is associated with a command means for stopping or restarting the spraying of the spots onto the yarns 14. These means may consist of stoppers commanded, for example, by electromagnets.
Successive patterns which differ from one another may thus be formed on the yarns 14 by means of the presence or absence of a spot of given color.
This variant of the method according to the invention is illustrated in FIG. 8.
In this example, the first pattern (top of FIG. 8) comprises a normal succession of spots A 1 , A 2 , A 3 (turbine T 1 ), B 1 , B 2 (turbine T 2 ) and C 1 , C 2 (turbine T 3 ).
In the second pattern, the stopper associated with the turbine T 2 has been closed, which is manifested by the absence of the spots B 1 , B 2 .
In the second pattern (at the bottom of FIG. 8) the stopper of the turbine T 1 has been closed, which is manifested by the absence of the spots A 1 , A 2 , A 3 .
This variant of the method according to the invention may be combined with one or other of the previous versions in order to corrupt the repetitive nature of the successive patterns to a greater or lesser extent depending on the quality of the final product which it is desired to obtain.
The versions of the method implemented by varying the speed of the turbines require very precise means for adjusting the speed of the motors.
The electric motors used must be of the brushless type and have low inertia so that their rotational speeds can change for example from 0 to 4000 rpm in a fraction of a second.
The electronic command circuit controlled by a computer must additionally be capable of very precisely adjusting the rotational speed of the various motors.
Of course, the invention is not limited to the examples which have just been described and numerous modifications may be made to it without departing from the scope of the invention.
Thus, modification of the shape of the spots in the successive patterns could be envisaged. | In a method for continuously dyeing textile yarns (14), the yarns travel continuously in front of a succession of stations (15a, 15b, 15c) for applying dyes of different colors, each station applying a series of spots onto the yarns (14), so that each yarn includes a succession of spots forming a pattern extending over a certain length (L) of the yarn (14) and which is continuously repeated. The stations (15a, 15b, 15c) for applying the dye are commanded individually in order to corrupt the repetitiveness of the successive patterns. The method is useful for improving the quality of carpets obtained from textile yarns (14). | 3 |
[0001] This application claims priority to U.S. provisional application No. 60/950,222, filed Jul. 17, 2007, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] This invention relates to cotton fiber processing and more particularly to an apparatus and method of separating foreign matter from fibrous cotton that has been ginned from the seed.
[0003] Prior methods and apparatus include those such as illustrated in U.S. Pat. No. 6,088,881, incorporated herein by reference, wherein a revolving perforated drum is used to allow air flow through the drum such that a cleaning cylinder may remove cotton fiber from the perforated drum and carry it past a plurality of cleaning grid bars, thereby separating the air flow and removing foreign matter from the fibers, before the fiber is doffed from the cleaning cylinder for subsequent air flow to downstream processing.
[0004] However, the perforated revolving cylinder of the '881 apparatus, revolving at velocities to prevent agglomeration of the tufts in the air stream, develops centrifugal forces that cause the fine trash and very short fibers that penetrate the perforations to accumulate on the interior surfaces of the perforated cylinder. These accumulations require the use of compressed air blasts to cause them to move axially out the open ends of the cylinder. While the compressed air blasts provide a solution to this problem of accumulations, the maintenance and cost of the compressed air system detracts from the otherwise excellent performance of the apparatus per the '881 patent.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] An apparatus embodying features of the invention is depicted in the accompanying drawing wherein:
[0006] FIG. 1 is a sectional side elevational view of an embodiment of an apparatus of the present invention.
BRIEF SUMMARY OF THE INVENTION
[0007] It is an object of the present invention to provide an improved method and apparatus for separating foreign matter from tufts of fibrous cotton. A further object of the invention is to eliminate the need for a compressed air system for cleaning a perforated separator cylinder, while maintaining the other features of the '881 patent by the use of a novel revolving separator in combination with a stationary arcuate perforated section.
DETAILED DESCRIPTION OF THE INVENTION
[0008] An improved apparatus and method according to the present invention is illustrated in reference to FIG. 1 , wherein fiber tufts comingled with foreign matter are pneumatically carried by a conveying air stream C into the apparatus via an air duct 11 as is well known in the art. Air duct 11 terminates adjacent an outer surface of a revolving cleaning cylinder 12 and a stationary separator housing. Duct 11 has an arcuate terminal wall portion 14 disposed adjacent to cleaning cylinder 12 to deliver the fiber tufts directly to a plurality of teeth 13 carried by the cleaning cylinder 12 and capable of holding the fiber tufts on said teeth 13 . The cylindrical housing comprises an arcuate non-porous surface 15 , a semi-cylindrical perforated surface or section 16 , and a non porous segment 15 a spaced from terminal portion 14 of duct 11 at the end of a minor chord drawn through revolving cylinder 12 , such that the cylindrical housing is open to duct 11 opposite terminal wall portion 14 . Perforated surface 16 is a stationary separator that is porous to air flow there through but impervious to desirable fiber flow there through. Rotating within the cylindrical housing is an revolving air separator 17 which is pervious to both fiber and foreign matter. As may be seen in FIG. 1 , terminal wall portion 14 of duct 11 converges toward revolving air separator 17 near cleaning cylinder 12 such that fiber tufts carried by the conveying air stream are directed substantially on to the teeth 13 of cleaning cylinder 12 while the direction of the conveying air flow is gradually changed toward the cylindrical housing comprising perforated surface 16 .
[0009] Again as may be seen in FIG. 1 , revolving separator 17 includes a plurality of circumferentially spaced outer surfaces 18 such that the spaces between spaced outer surfaces 18 are sufficient to allow the conveying air to pass between the spaced surfaces 18 as air duct 11 converges toward the spaced surfaces 18 without abruptly increasing the conveying air velocity. Outer surfaces 18 pass proximal to the revolving cleaning cylinder 12 and semi-cylindrical stationary surface 16
[0010] In one embodiment outer surfaces 18 are defined by circumferentially spaced apart flexible belt-like strips running generally parallel to the axis of rotation of air separator 17 and generally radial to the axis of rotation. The strips are flexible radially and may be made of soft material to resist damage to the cleaning cylinder 12 or semi-cylindrical stationary surface 16 . In another embodiment, spaced outer surfaces 18 are defined by circumferentially spaced apart brush strips running generally parallel to the axis of rotation with the bristles facing outward generally radial to the axis of rotation of the air separator 17 . Suitable hub plates 22 hold the hubs 25 of the strips 18 in place forming an open reel. In either embodiment, the strips are preferably set at a deflection angle of the strips approximately 15 degrees backward from radial to the axis of rotation of the rotating separator 17 relative to its direction of rotation.
[0011] The conveying air stream C thus passes through the air separator 17 and is exhausted from the cylindrical housing via perforated surface 16 to become exhaust air stream E. It is worthwhile to note that as outer surfaces 18 rotate across perforated surface 16 the surfaces 18 substantially sweep away any accumulations of matter on the stationary separator surface 16 and return any desirable fiber back to the conveying air stream C, proximal to terminal portion 14 of duct 11 . To effectively accomplish this, revolving outer surfaces 18 move at velocities that develop centrifugal forces sufficient to cause heavier than air matter revolving with the outer surface 18 to move substantially radially outwardly. Further the hubs or inner surface 25 of the strips 18 are configured to resist accumulation of matter heavier than air thereon, such that the rotation of the hub 25 and surfaces 18 moves such matter outwardly where it may be directed towards cleaning cylinder 12 . The rotation of revolving outer surfaces 18 is such that the commingled fiber and foreign matter are exposed to the teeth 13 of the cleaning cylinder 12 while the revolving outer surfaces 18 are rotating toward stationary semi cylindrical surface 16 .
[0012] As will be understood from the prior art, the rotation of cleaning cylinder 12 carries the tufts past a stripping bar 27 and plurality of cleaning grid bars 23 disposed to separate a major portion of foreign matter from the cleaning cylinder 12 , which foreign matter may be disposed via a trash conveyor system for subsequent collection and baling. In the embodiment depicted, foreign matter is disposed via a waste airflow W.
[0013] As will also appreciated, a rotating doffing cylinder or brush 24 removes the cleaned tufts from the teeth 13 of cleaning cylinder 12 and delivers the cleaned fibers to duct 26 . In the embodiment depicted, the cleaned tufts may be entrained in a doffing air flow D which passes adjacent doffing brush 24 and into duct 26 .
[0014] The apparatus may be used to process cotton fiber according to the following description. Spaced apart individual tufts of fiber are conveyed in a high speed conveying air stream C to minimize agglomeration of the tufts, first exposing the air stream to revolving separator 17 which is porous to radially inward and outward air flow and revolving at speeds developing centrifugal forces that cause the fiber tufts and foreign matter rotationally moving with the porous revolving separator 17 to resist radially inward movement such that the fiber tufts and foreign are substantially removed from the conveying air C as it passes through the porous revolving air separator 17 . Thus, the preponderance of the fiber tufts and foreign matter are delivered directly to revolving toothed cleaning cylinder 12 in close proximity to the revolving separator 17 .
[0015] A stationary generally cylindrical surface is located downstream of the revolving toothed cylinder 12 relative to the rotation of and proximal to the porous revolving air separator 17 . The stationary arcuate surface includes a porous section 16 being porous to air flow there through, but impervious to desirable fiber flow, and preferably contains one or more non-porous sections 15 . The rotational movement of the outer surfaces 18 carried by revolving porous air separator 17 proximate stationary arcuate surface sweeps any accumulations of desirable fiber from the upstream side of arcuate stationary surface 15 , 16 delivering the fibers back into the conveying air stream C. The periphery of the revolving separator 17 should be porous to radially inward and outward air flow and have means on the radially inward surfaces to prevent the accumulation of matter heavier than air.
[0016] Revolving toothed cylinder 12 holds the tufts while revolving past stripping bar 27 and cleaning bars 23 that strip foreign matter from the fiber tufts. A doffing brush or roller 24 revolving proximate and counter to toothed cleaning cylinder 12 removes the cleaned fibers from teeth 13 and delivers the cleaned fiber tufts from the process.
[0017] While the forgoing specification describes only a few embodiments of the present invention, the invention is not so limited and is intended to encompass the full scope of the claims appended hereto. | An apparatus for cleaning foreign matter from separated tufts of fiber uses a revolving open reel type structure mounted within a porous housing to separate a conveying air stream from tufts of fiber conveyed thereby and deliver the tufts to a toothed cleaning cylinder which passes beneath a plurality of cleaning bars. The open reel utilizes brush like outer surfaces to sweep tufts of fiber from the housing back into the air stream adjacent the cleaning cylinder. | 3 |
BACKGROUND OF THE INVENTION
Containers and, in particular, open-mouth rigid containers, such as glass bottles or the like, are commonly subjected to post treatment wherein various coatings are applied to the outer surfaces of the container. Such coatings are applied, for example, to improve fracture resistance, impart lubricous properties and, in some cases, to color the containers. The coatings are applied by conventional techniques, such as dipping or by electrostatic deposition, and cured by heat treatment.
The containers are generally carried through the coating and curing stages on hangers suspended from a continuous conveyor, the containers being releasably engageable with the hanger. Furthermore, it is preferable that the containers be supported interiorly by the hanger, one such means of providing internal support for the container being disclosed in U.S. Pat. No. 3,777,875, assigned to the assignee of the present invention.
In the said patent, the hanger member terminates in a frusto-conical resilient member which is forcibly inserted into the container mouth and frictionally engages the inner surface thereof whereby the container may be carried through the various processing stages. The container is released by forcibly disengaging the resilient insert by the downward stroke of a cylindrical sleeve-like member actuated by a cam means.
This container transporting means suffers, however, from the disadvantage that the resilient frusto-conical member must be sized to engage a container mouth of a particular diameter, with the consequence that the resilient members must be changed to accommodate containers having only slightly differing mouth dimensions. Moreover, the forcible engagement and disengagement of the resilient member results in increased wear and frequent replacement of the resilient member. Additionally, the containers must be accurately aligned with their respective hangers in order to assure proper engagement of the resilient member with the container mouth.
SUMMARY OF THE INVENTION
According to the invention a hollow, elongated elastomeric diaphragm, carried on the lower end of the hanger member, is inserted into the mouth of the container. A double-acting hydraulic cylinder integral with the hanger member is energized to impart stored energy through a fluid medium to expand the diaphragm, the expanded diaphragm frictionally engaging the interior surface of the container mouth. The container is disengaged by relieving the static pressure, which deflates the diaphragm. The hydraulic system is energized, i.e., the diaphragm is inflated, at all times other than when the container is picked up and removed, at which times the system is de-energized, i.e., the diaphragm is deflated.
DESCRIPTION OF THE DRAWINGS
The invention is illustrated in a preferred embodiment by the following drawings, wherein:
FIG. 1 is an elevation view, partly in section, of the container transporting device in an energized condition;
FIG. 2 is an elevation view, partly in section, of the container transporting device in a de-energized condition;
FIG. 3 is an expanded sectional view of an elastomeric diaphragm usable in the present invention;
FIG. 4 is an expanded view, partly in section, of the elastomeric diaphragm of FIG. 3 modified for electrostatic spraying operations;
FIG. 4a is a cross-sectional view of FIG. 4 taken along the line A--A; and
FIGS. 5a to 5f represent schematically the sequence of operation of the container transporting device of the invention.
DESCRIPTION OF THE INVENTION
With reference to FIG. 1, the container supporting and transporting device of the invention is depicted at 10 in its energized condition. The device 10 is in the energized condition at all times, except when it is engaging a container or when it is disengaging from a container. The device 10 comprises a linearly extending hollow rod or tube 11 which is connected at its upper end via a fitting 12 to the lower end of a cylinder 13 and is adapted at its lower end to be connected with a hollow, elongated elastomeric diaphragm 17 via fittings 14 and 15 and ferrule 16. The tube 11 is fabricated of any structurally suitable material, preferably steel or stainless steel. The diaphragm 17 is formed from a compression molded elastomeric material, for example, a silicone rubber or the like capable of withstanding continuous operating temperatures of about 425°F without deformation or loss of elastic memory. A silicone rubber marketed under the tradename "Blensil" by General Electric Company has proved to be satisfactory. A cylindrical sleeve 42 slidably mounted on tube 11 may also be provided. The sleeve 42 serves the purpose of protecting the lower section of the tube, fittings and diaphragm from contact with the particular coating or pigment being applied to the container, the lower end of the sleeve bearing on the top surface of the container. The sleeve is preferably fabricated on a non-conductive, chemically resistant material, such as "Teflon" or the like.
A piston 18 is disposed within cylinder 13, the cylinder 13 being movable with respect to the piston 18, as will be explained hereinafter. A piston rod 19 is secured to the piston 18, the rod extending through the upper end of the cylinder 13 which is provided with a seal 20. The upper end of the piston rod 19 is connected to a bracket 21, the bracket 21 being rigidly affixed to a conveyor means 25 such as, for example, a monorail conveyor, via fastening means 26, such as a nut and bolt as shown. It is thus seen that the piston 18, piston rod 19 and bracket 21 form a linear fixed assembly depending from the conveyor means 25 and is also fixed with respect to vertical movement of cylinder 13.
A sprocket 27 is fixedly mounted on the upper end of cylinder 13 and coaxial therewith. Low-friction rotation of the assembly is assured by the provision of bearing means 28 mounted about the upper threaded end of piston rod 19, the bearing means 28 being secured by a lock washer 29 and a nut 30. The sprocket 27 also serves as a bearing or pressure plate to de-energize the device as will be described hereinafter.
A spring 31 is disposed within the upper portion 32 of cylinder 13 and is expanded against the fixed piston 18 and cylinder 13. As the spring is used to store energy, it is preferred that it have a capacity of at least twelve times the container weight at maximum operating temperature. The lower portion 33 of cylinder 13 serves as a fluid reservoir. The fluid 34 is a non-compressible thermally stable liquid which is compatible with all parts of the device with which it is contacted. The fluid 34 completely fills the reservoir 33, tube 11 and diaphragm 17. To eliminate loss of fluid due to leakage between the cylinder wall and the piston, resulting in a loss of working pressure, the piston is provided with an annular fluid seal 35. To prevent air from becoming entrapped on the working side of the cylinder, the piston is provided with a second annular seal 36. The fluid seal 35 must be of a material that is capable of withstanding operating temperatures, i.e., about 425°F, and be compatible with the hydraulic fluid, whereas the air seal 36, which is not in contact with the hydraulic fluid, must only be capable of withstanding operating temperatures. A material such as "Viton" has been found to be suitable for both the fluid and air seals. A vent hole 37 is provided in the upper portion 32 of cylinder 13 to provide for relieving back pressure on piston 18, as well as to provide access for lubricating the spring 31.
It is important that the fluid side of the device contain no compressible fluid, e.g., air or other gases, as even partial fluid compressibility will use the energy required by the diaphragm to maintain a friction coefficient sufficient to carry the container. As the degree of freedom in the diaphragm must be as low as possible to maintain desirable temperature elasticity and longevity characteristics, the relatively high degree of freedom resultant from air pockets would use a substantial portion of the energy necessary to inflate the diaphragm to the required extent. Moreover, as air is not thermally stable, heating at processing temperatures could cause overexpansion of the diaphragm were air entrapped on the fluid side. Additionally, entrapped air would require an unrealistically high amount of cylinder displacement.
It is, of course, to be understood that the term "non-compressible", as applied to the fluid contemplated, is used as a matter of practical convenience as all liquids are to some extent compressible. However, the compressibility is so small as to be negligble in most applications and liquids are thus said to be practically non-compressible. For example, a pressure of one p.s.i. will compress a given volume of water only about one part in 300,000.
As beforementioned, FIG. 1 is illustrative of the device in its energized condition. In this state, the compression spring 31 is expanded against the piston 18, thus statically loading the fluid 34 in reservoir 33, which load is transmitted through the fluid in tube 11, thereby expanding the resilient walls of the elastomeric diaphragm 17 to frictionally engage the inner surface of the mouth of a container 41.
The term "static load" as used herein can be analogized to a static load as applied to an axial bar wherein a load that is just touching the end of the bar is suddenly released such that the velocity of approach is zero. The load is constant throughout the entire deformation and the internal force in the bar increases from zero to some value SA wherein S is the unit stress, i.e., the amount of force per unit area of surface, and A is the cross-sectional area of the bar to which the load is applied. In the instant case, however, a fluid rather than a solid material is static loaded.
FIG. 2 is illustrative of the means by which the device is de-energized, whereby the diaphragm 17 is deflated to permit insertion into or withdrawal of the same from a container. At the points of pick-up and take-off of the container, the assembly 10 travels under a cam means 36. A preferred type of cam means comprises a pair of overhead rails 37, and associated V-belts 38, the belts being backed by bearings 39 supported in the rails 37. The cam belts 38 bear on either side of the top surface of the sprocket or pressure plate 27, depressing the same which results in vertical downward displacement of cylinder 13 with respect to the fixed piston 18 and rod 19. Downward displacement of cylinder 13 results in compression of spring 31 and enlargement of the volume of fluid reservoir 33, thus relieving the static load on the fluid 34 in the reservoir 33, tube 11, and diaphragm 17, the diaphragm deflating and returning to its fabricated dimensions, thus permitting frictionless insertion into or removal from the container 41. Disengagement of the cam means 36 results in expansion of spring 31, which causes the assembly 10 to return to its energized state as shown in FIG. 1.
It is preferred that the volume displacement capacity on the fluid side should be a minimum of 10% greater than the volume displacement of the diaphragm and a maximum of 40% greater. The minimum excess displacement will permit the cylinder to compensate for diaphragm elasticity and assembly tolerance error whereas the maximum excess displacement will limit fluid contamination in the event of rupture or mechanical failure of the diaphragm.
FIGS. 5a to 5f are illustrative of the mode of operation of the container supporting and transporting device of the invention. A container 44 having an open mouth portion 43 is advanced via a conveyor pallet 46 to a position where the mouth 43 is approximately aligned with energized assembly 10, (FIG. 5a). The container shown is a typical glass bottle, but it is apparent that a variety of other rigid containers of different design may be used, as the diaphragm dimensions may be varied to accommodate any open-mouthed container. Concurrently with the alignment of the container 44 with assembly 10, the cam means 36 de-energizes the assembly in the manner described with reference to FIG. 2 and the deflated diaphragm 17 is inserted into the bottle mouth 43. While insertion of the diaphragm into the bottle mouth can be effected by relative downward movement of the assembly with respect to the bottle, it is desirable to effect insertion by moving the container upward relative to the assembly via an inclined conveyor 48 as depicted, (FIG. 5b). As the cam disengages, the assembly is energized, causing inflation of the diaphragm 17 which frictionally engages the inner surface of the mouth portion 43, (FIG. 5c). The suspended container is then conveyed through the various processing stages, such as the electrostatic coating stage 45 depicted in FIG. 5d. At the completion of processing, the assembly is de-energized by engagement with another cam means 36. The diaphragm 17 is again deflated and withdrawn from the container, (FIG. 5d). Disengagement of the cam means returns the assembly 10 to its energized condition, (FIG. 5f).
Although FIG. 5 illustrates the use of a pallet to maintain the container in vertical axial alignment with the transporting device at the points of pick-up and take-off, the use of a pallet is optional as it has been found that, due to the resilient member, the container may be inclined as much as 12° to the vertical axis of the transporting device without affecting the ability of the device to satisfactorily engage with or disengage from the container.
FIG. 3 is illustrative of a preferred configuration of the elastomeric diaphragm of the invention in its fabricated state. The diaphragm 50, molded from a silicone rubber elastomer or the like, although of unitary construction, can best be described as consisting of three parts, namely, a tip portion 51, a body portion 52 and a rear portion 53. The tip portion 51 is of solid construction and is of a generally conical configuration. The body portion 52 is configured as a hollow cylinder. The rear portion 53 is also in the form of a hollow cylinder with an outside diameter slightly greater than the outside diameter of the body portion 52. As shown in FIGS. 1 and 2, the rear portion 53 is in engagement with the tube 11 via fittings 14 and 15 and is secured thereto by ferrule 16. Consequently, as the rear portion 53 is in adaptive engagement with the tube 11 and the tip portion 51 is of solid construction, only the body portion 52 will be expanded substantially radially outwardly along its axial length by the application of the static hydraulic load when the device is energized as described hereinabove.
In order to assure dynamically stable pick-up and removal of the container by the diaphragm, the same is preferably dimensioned such that for a given overall length, the tip portion 51 comprises from 15 to 20% of the length, the body portion 52 comprises from 45 to 60% of the length, and the rear portion comprises from about 30 to 35% of the length. The inside diameter of the body portion 52 is preferably from 60 to 80% of its outside diameter, the inside diameter of the rear portion 53 being from 80 to 90% of the inside diameter of the body portion 52 and the outside diameter of the rear portion 53 being from 120 to 130% of the outside diameter of the body portion 52.
For example, in order to engage a container mouth having an inside diameter of from 0.625 to 0.700 inch (1.59 to 1.78 cm), an elastomeric diaphragm of substantially the following dimension is recommended:Length, overall: 3.00 inches (7.62 cm)Length, tip portion: 0.50 inch (1.27 cm)Length, body portion: 1.50 inches (3.81 cm)Length, rear portion: 1.00 inch (2.54 cm)O. D., body portion: 0.60 inch (1.52 cm)I. D., body portion: 0.42 inch (1.07 cm)O. D., rear porotion: 0.72 inch (1.83 cm)I. D., rear portion: 0.375 inch (0.95 cm)
It has been common practice to apply coatings or the like to containers by electrostatic means. Generally speaking, an electrostatic coating system includes a spray generator from which the coating composition emanates in the form of very finely divided particles. The particles are passed near a high voltage probe or electrode whereby an electrostatic charge is induced on the particles. In order to assure deposition of a uniform adherent coating to the container, it is preferable to provide a means of maintaining a potential difference between the spray particles and the container, one such means being illustrated in FIGS. 4 and 4a.
FIGS. 4 and 4a depict a diaphragm 60 similar to the diaphragm shown in FIG. 3, the diaphragm 60 being adapted and modified to assure maintenance of the requisite potential difference between the charged spray particles and the container in the following manner.
A small radially extending hole 64 is provided in the tip portion 61 of diaphragm 60 the hole 64 being bored completely through the tip portion and communicating with vertically extending channels 65 formed in the outer wall 66 of body portion 62. Extending inwardly from the inner wall 67 of body portion 62 and corresponding to channels 65 are ribs 68. A length of small diameter, e.g., about 24-gauge, conductive wire, preferably copper wire (not shown), is threaded through hole 64 and recessed in channels 65, the wire being held in place by ferrule 16 (FIGS. 1 and 2). As the wire is completely recessed in the channels 65, when the diaphragm is in its fabricated or de-energized conditions, the wire will not abrade the container upon insertion of the diaphragm into the container mouth. When the diaphragm is energized, i.e., expanded, the wire expands with the diaphragm wall and contacts the inner surface of the container mouth, thus providing an electrically conductive path to maintain the requisite potential difference to assure uniform deposition of the coating.
Although the invention, in its preferred embodiments, has been described in considerable detail in the foregoing disclosure, it is to be understood that such description is only illustrative of the invention and that many variations will be apparent therein to those skilled in the art without departing from the spirit and scope thereof. | Apparatus is disclosed for releasably supporting and transporting rigid open-mouthed containers by engaging the interior surface of the container mouth with an inflatable elongated elastomeric diaphragm, means being provided for inflating and deflating the diaphragm. The apparatus is particularly useful in suspending and conveying heated glass bottles through various processing stages wherein various coatings are applied to the outer surfaces of the bottles. | 1 |
BRIEF DESCRIPTION OF THE INVENTION
Compounds having the formula ##SPC2##
The 5-oxide and 5,5-dioxide thereof, and the pharmaceutically acceptable acid addition salts thereof, have useful pharmacological activity, and can be used in mammals to treat inflammation. In formula I, and throughout the specification, the symbols are as defined below.
A can be a straight or branched chain alkylene group having 2 to 5 carbon atoms; and
R 1 can be hydrogen, alkyl, alkoxy, trifluoromethyl, halogen, nitro, dialkylamino, or alkylsulfinyl;
Z can be CH 2 , oxygen or N--R 2 , wherein R 2 is hydrogen, alkyl, aryl, or arylalkyl.
The terms alkyl and alkoxy, as used throughout the specification (by themselves or as part of a larger group) refer to groups having 1 to 8 carbon atoms. Alkyl and alkoxy groups having 1 to 3 carbon atoms are preferred.
The term aryl, as used throughout the specification (by itself or as part of a larger group) refers to phenyl or phenyl substituted with an alkyl, alkoxy, or halogen group. Phenyl is the preferred aryl group.
The term halogen, as used throughout the specification, refers to fluorine, chlorine, bromine, and iodine; fluorine and chlorine are preferred.
DETAILED DESCRIPTION OF THE INVENTION
The compounds of formula I (and the 5-oxides and 5,5-dioxides thereof) are prepared using as starting materials a substituted tetrahydro-4H-thiopyran-4-one having the formula ##SPC3##
Or a 1-oxide or 1,1-dioxide thereof, and a hydrazine having the formula ##SPC4##
The compounds of formulas II and III are readily obtainable; see, for example, Journal of the American Chemical Society, 79:156 (1957) and Journal of Medicinal Chemistry, 7:493 (1964).
A substituted tetrahydro-4H-thiopyran-4-one of formula II can be prepared by reacting tetrahydro-4H-thiopyran-4-one with an appropriate benzaldehyde having the formula ##SPC5##
The corresponding 1-oxide or 1,1-dioxide can be prepared by reacting a substituted tetrahydro-4H-thiopyran-4-one of formula II with an appropriate amount of an oxidizing agent; sodium periodate is preferred for preparing a 1-oxide and hydrogen peroxide is preferred for preparing a 1,1-dioxide.
A hydrazine of formula III can be prepared by reacting an excess of hydrazine (H 2 NNH 2 ) with a haloamine having the formula ##SPC6##
Wherein X is chlorine or bromine.
Reaction of a substituted tetrahydro-4H-thiopyran-4-one of formula II (or a 1-oxide or 1,1-dioxide thereof) with a hydrazine of formula III yields a product of formula I, or the corresponding 5-oxide or 5,5-dioxide. The reaction can be run in an organic solvent, preferably a lower alkanol such as methanol. While reaction conditions are not critical, the reaction will preferably be run at, or near, the reflux temperature of the solvent.
Alternatively, the compounds of formula I can be obtained by first reacting a substituted tetrahydro-4H-thiopyran-4-one of formula II with a hydroxylalkyl hydrazine having the formula
H.sub.2 NNH--A--OH VI
to form an intermediate having the formula ##SPC7##
An alcohol of formula VII can be reacted with an alkylsulfonyl or arylsulfonyl halide, preferably p-toluenesulfonyl halide, to yield a compound of the formula ##SPC8##
wherein Y is alkyl or aryl. The intermediate of formula VIII can be treated with a heterocyclic compound having the formula ##SPC9##
to yield the products of formula I.
The 5-oxide and 5,5-dioxide derivatives of a compound of formula I can, alternatively, be prepared by oxidizing the corresponding compound of formula I. Oxidation of a compound of formula I using one equivalent of sodium periodate or hydrogen peroxide yields the corresponding sulfoxide derivative. Oxidation of a compound of formula I using potassium permanganate or excess hydrogen peroxide yields the corresponding sulfonyl derivative. Alternatively, the sulfoxide and sulfonyl derivatives can be prepared by treating compounds of formula I with m-chloroperbenzoic acid. Treating a compound of formula I with an equivalent of m-chloroperbenzoic acid for from 2 to 24 hours at room temperature yields the corresponding sulfoxide derivative. Treating a compound of formula I, or a sulfoxide derivative of a compound of formula I, with two equivalents of m-chloroperbenzoic acid for 2 to 24 hours at room temperature (or for a shorter time with slight heating) yields the corresponding sulfonyl derivative.
The compounds of formula I form acid addition salts with inorganic and organic acids. These acid addition salts frequently provide useful means for isolating the products from reaction mixtures by forming the salt in a medium in which it is insoluble. The free base may then be obtained by neutralization, e.g., with a base such as sodium hydroxide. Any other salt may then be formed from the free base and the appropriate inorganic or organic acid. Illustrative are the hydrohalides, especially the hydrochloride and hydrobromide which are preferred, sulfate, nitrate, phosphate, borate, acetate, tartrate, maleate, citrate, succinate, benzoate, ascorbate, salicylate, methanesulfonate, benzenesulfonate, toluenesulfonate and the like.
The compounds of formula I, the pharmaceutically acceptable acid addition salts thereof, and the 5-oxide and 5,5-dioxide thereof, are useful in treating inflammation in mammalian species, e.g., rats, dogs, cats, monkeys, etc. Joint tenderness and stiffness (in conditions such as rheumatoid arthritis) are relieved by the above described compounds.
The compounds of this invention can be formulated for use as anti-inflammatory agents according to accepted pharmaceutical practice, in oral dosage forms such as tablets, capsules, elixirs, or powders, or in an injectable form in a sterile aqueous vehicle prepared according to conventional pharmaceutical practice. The compounds of this invention may be administered in amounts of 100 mg/70kg/day to 2 g/70kg/day, preferably 100 mg/70kg/day to 1 g/70kg/day.
The following examples are specific embodiments of this invention.
EXAMPLE 1
2,3,3a,4,6,7-Hexahydro-2-[3-(4-methyl-1-piperazinyl)propyl]-3-phenyl-7-(phenylmethylene)thiopyrano[4,3-c]pyrazole, maleate salt (1:2)
Tetrahydro-3,5-bis-(phenylmethylene)-4H-thiopyran-4-one (5.3g) is refluxed with 3.4g of 3-(4-methyl-1-piperazinyl)propylhydrazine in a mixture of 40 ml of chloroform and 160 ml of methanol for 2 hours. The solvent is removed in vacuo to yield the free base of the title compound as a crude product.
The crude free base is dissolved in 50 ml of warm acetonitrile and treated with a warm solution of 4.5g of oxalic acid in 80 ml of acetonitrile. A precipitate forms almost immediately. The mixture is stirred at room temperature for 30 minutes and then cooled in an ice bath. The precipitate is collected by filtration and dried to yield 11g of crude 2,3,3a,4,6,7-hexahydro-2-[3-(4-methyl-1-piperazinyl)propyl]-3-phenyl-7-(phenylmethylene)thiopyrano[4,3-c]pyrazole, oxalate salt (1:2)melting point 202°-203° C.
The dioxalate salt is suspended in water and chloroform (100 ml of each) and treated with 9.9 g of potassium carbonate. The aqueous layer is separated and extracted with chloroform. The chloroform layers are combined and concentrated in vacuo to give the title compound as a free base.
The dimaleate salt of the title compound is prepared using the procedure described for the preparation of the dioxalate salt, and has a melting point of 179°-180° C.
EXAMPLE 2
2,3,3a,4,6,7-Hexahydro-2-[3-(4-methyl-1-piperazinyl)propyl]-3-phenyl-7-(phenylmethylene)thiopyrano[4,3-c]pyrazole
A suspension of 4 g of the dimaleate salt of the title compound (prepared as described in Example 1) in water and chloroform (100 ml of each) is treated with 3.2 g of anhydrous potassium carbonate in portions. The aqueous layer is separated and washed with chloroform. The combined chloroform layers are dried using magnesium sulfate and concentrated in vacuo. The residue is crystallized from ether/hexane to give 1.8 g of the title compound melting point 90.5°-92.5° C.
EXAMPLE 3-14
By reacting the appropriate tetrahydro-3,5-bis-(phenylmethylene)-4H-thiopyran-4-one with the appropriate heterocyclicalkylhydrazine, and where necessary treating the free base with the appropriate acid, the compound listed below is obtained
__________________________________________________________________________ ##STR1##Example Q R.sub.1 A Z salt melting point__________________________________________________________________________3 S 4-methoxy (CH.sub.2).sub.3 NCH.sub.3 dimaleate 170.5-172° C4 S 4-methyl (CH.sub.2).sub.3 NCH.sub.3 dimaleate 174-176° C5 S 2-methyl (CH.sub.2).sub.3 NCH.sub.3 dimaleate 168.5-170° C6 S 4-methylsulfinyl (CH.sub.2).sub.3 NCH.sub.3 dimaleate 173-175° C7 SO.sub.2 H (CH.sub.2).sub.3 NCH.sub.3 dimaleate 192-195° C8 SO.sub.2 4-methoxy (CH.sub.2).sub.3 NCH.sub.3 dimaleate 173.5-175° C9 SO.sub.2 2-methyl (CH.sub.2).sub.3 NCH.sub.3 dimaleate 165.5-167.5° C10 SO H (CH.sub.2).sub.2 NH11 S 3-chloro (CH.sub.2).sub.2 ##STR2##12 S 2-trifluoromethyl (CH.sub.2).sub.4 ##STR3##13 S 4-nitro (CH.sub.2).sub.5 CH.sub.214 S 4-dimethylamino (CH.sub.2).sub.3 O__________________________________________________________________________ | Anti-inflammatory activity is exhibited by compounds having the formula ##SPC1##
The salts thereof, and the 5-oxide and 5,5-dioxide thereof, wherein A is a straight or branched chain alkylene group; R 1 is hydrogen, alkyl, alkoxy, trifluoromethyl, halogen, nitro, dialkylamino, or alkylsulfinyl; and Z is CH 2 , oxygen or N-R 2 , wherein R 2 is hydrogen, alkyl, aryl, or arylalkyl. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of Ser. No. 09/908,274 filed Jul. 18, 2001 now U.S. Pat. No. 6,467,929.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
REFERENCE TO A MICROFICHE APPENDIX
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention pertains generally to mounting devices, and more particularly, to a laser diode module mounting apparatus.
2. Background of the Invention
Use of portable electronic devices, such as pagers, cellular telephones, and walkie-talkies have become widely prevalent. Since portability is inherent with such electronic devices, many various attachment or mounting apparatuses have been developed and used to allow for the attachment of these electronic devices onto a person's apparel. There have also been many attachment or mounting apparatuses that also allow for the convenient storage of these electronic devices by placement onto a holder, rack, or the like. All the attachment or mounting apparatuses, however, do not allow for the use of the electronic device when the device is either attached to the person's apparel or otherwise mounted onto an object.
A need for using or operating a portable electronic device arises from a portable electronic device used for projecting a laser-based image. An example of such an electronic device is known as Laser Diode manufactured by Transverse Industries Company, Ltd. The Laser Diode is a battery powered laser emitter that is capable of projecting a variety of images onto a variety of surfaces. The Laser Diode is enclosed within a generally modular housing. Unlike a laser pointing device, which only projects a dot on the targeted surface, the Laser Diode is capable of projecting images, such as a sun, moon, star, happy face, or flying saucer. It is conceivable that in addition to the aforementioned images, letters, initials, acronyms, words, phrases, slogans or sentences may also be projected by such laser emitting devices.
Although the Laser Diode may be held by the user and pointed at a desired location while projecting the image, it is often desirable to project the image at a desired location while the Laser Diode is attached onto some apparel worn by the user or while the Laser Diode is mounted onto a fixed object, such as a pole, table edge, or refrigerator or the like. This enhances not only the practical applications for the Laser Diode, but also furthers its entertainment appeal at, for example, a party, during a concert, when camping or during night events and activities.
Accordingly, there is a need for an apparatus for attaching or mountmg a laser diode module that enables the laser diode module to be aimed or pointed at a specified location while the laser diode module is either attached to some item of apparel worn by the user or otherwise mounted on an object. The present invention satisfies these needs, as well as others, and generally solves the deficiencies found in the background art.
BRIEF SUMMARY OF THE INVENTION
The present invention pertains to a laser diode module attachment and mounting apparatus that allows for aiming, and hence projecting, a laser image on a desired target while the laser diode module is either attached to an item of apparel worn by the user or mounted onto an object. By way of example and not of limitation, the laser diode module attachment and mounting apparatus generally comprises a first means for attaching a laser diode module onto an object, a second means for adjusting a laser diode module connected to the first means for attaching the laser diode module, and an attachment mechanism for securing second adjustment means to the laser diode module.
The first means for attaching a laser diode module is adapted for the attachment or mounting onto an item of apparel or otherwise a generally fixed object. The second means for adjusting a laser diode module is connected to the first attaching means and allows for the directional positioning and adjustment of a laser diode module around one axis of rotation and/or two axis of rotation. The attachment mechanism affixes the laser diode module to the second adjustment means, and therefore renders the laser diode module adjustable when the first attachment means is attached or mounted to an object.
The present invention has been outlined in a rather broad fashion in order that the detailed description that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.
An object of the invention is to provide a means for attaching a laser diode module to an item of apparel.
Another object of the invention is to provide a means for mounting a laser diode module onto a fixed object.
Still another object of the invention is to provide a means for attaching or mounting a laser diode module that allows for directional adjustability of the laser diode module when attached on an item of apparel or mounted on a fixed object.
Further objects and advantages of the invention will be brought out in the following portions of the specification, wherein the detailed description is for the purpose of fully disclosing preferred embodiments of the invention without placing limitations thereon.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more fully understood by reference to the following drawings that are for illustrative purposes only:
FIG. 1 is a perspective view of an apparatus for attaching or mounting a laser diode module in accordance with the present invention, shown with a first embodiment of a first means for attaching or mounting the laser diode module and a first embodiment of a second means for adjusting the laser diode module.
FIG. 2 is a perspective view of an apparatus for attaching or mounting a laser diode module shown with a second embodiment of a first means for attaching or mounting the laser diode module, along with a second embodiment of a second means for adjusting the laser diode module.
FIG. 3 is a perspective view of the apparatus shown in FIG. 2, shown attached to a belt.
FIG. 4 is a perspective view of an apparatus for attaching or mounting a laser diode shown with a third embodiment of a first means for attaching or mounting the laser diode module, along with a first embodiment of a second means for adjusting the laser diode module.
FIG. 5 is a perspective view of the apparatus shown in FIG. 4, shown attached to a pole.
FIG. 6 is a perspective view of an apparatus for attaching or mounting a laser diode module shown with a fourth embodiment of a first means for attaching or mounting the laser diode module, along with a first embodiment of a second means for adjusting the laser diode module.
FIG. 7 is a perspective view of an apparatus for attaching or mounting a laser diode module shown with a fifth embodiment of a first means for attaching or mounting the laser diode module, along with a first embodiment of a second means for adjusting the laser diode module.
FIG. 8 is a perspective view of the apparatus shown in FIG. 7, shown attached to a table.
FIG. 9 is a perspective view of an apparatus for attaching or mounting a laser diode module shown with a sixth embodiment of a first means for attaching or mounting the laser diode module, along with a first embodiment of a second means for adjusting the laser diode module.
FIG. 10 is a perspective view of an apparatus for attaching or mounting a laser diode module shown with a seventh embodiment of a first means for attaching or mounting the laser diode module, along with a first embodiment of a second means for adjusting the laser diode module.
FIG. 11 is a perspective view of an apparatus for attaching or mounting a laser diode module shown with a seventh embodiment of a first means for attaching or mounting the laser diode module, along with a second embodiment of a second means for adjusting the laser diode module.
FIG. 12 is a perspective view of the apparatus shown in FIG. 11, shown attached to a cap.
FIG. 13 is a perspective view of an apparatus for attaching or mounting a laser diode module shown with a sixth embodiment of a first means for attaching or mounting the laser diode module, along with a third embodiment of a second means for adjusting the laser diode module.
FIG. 14 is a cross-sectional view of the sixth embodiment of a first means for attaching or mounting the laser diode module, shown in FIG. 13 .
FIG. 15 is a perspective view of an apparatus for attaching or mounting a laser diode module shown with the second embodiment of a first means for attaching or mounting the laser diode module, along with a fourth embodiment of a second means for adjusting the laser diode.
FIG. 16 is a perspective view of the apparatus shown in FIG. 15, shown attached to a cap.
DETAILED DESCRIPTION
Referring more specifically to the drawings, for illustrative purposes the present invention is embodied in the apparatus generally shown in FIG. 1 through FIG. 16 . It will be appreciated that the apparatus may vary as to configuration and as to details of the parts without departing from the basic concepts as disclosed herein.
Referring first to FIG. 1, an apparatus 10 for attaching or mounting a laser diode module, in accordance with the present invention, is generally shown. Apparatus 10 comprises a first means 12 for attaching a laser diode module 14 , a second means 16 for adjusting laser diode module 14 , and an attachment mechanism 18 for securing second means 16 for adjusting laser diode module 14 to laser diode module 14 .
First means 12 for attaching a laser diode module 14 generally comprises a plate 20 , a gripping member 22 , a pivot assembly 24 , and a spring (not shown). Plate 20 includes an upper end 26 , a lower end 28 , a front face 30 , and a rear face 32 . Gripping member 22 is disposed on rear face 32 of plate 20 and includes an upwardly disposed handle 34 and a lower extent 36 . Pivot assembly 24 couples gripping member 22 to plate 20 while providing for pivotal motion of gripping member 22 relative to plate 20 . The spring located within pivot assembly 24 biases gripping member 22 by compressing lower extent 36 of gripping member 22 against rear face 32 of plate 20 while in a rest position.
Second means 16 for adjusting laser diode module 14 comprises a ball and socket joint 38 and a support member 40 . Support member 40 is integrally coupled to upper end 26 of plate 20 and extends generally perpendicularly from front face 30 of plate 20 . Ball and socket joint 38 is connected to support member 40 by a screw 42 . Other forms of connecting ball and socket joint 38 to support member 40 are contemplated, such as but not limited to, gluing or press fitting.
Laser diode module 14 is secured to ball and socket joint 38 by attachment mechanism 18 , which are threads (not shown) within laser diode module 14 adapted to receive a stud 44 extending from ball and socket joint 38 . This allows for the removal and replacement of laser diode module 14 from apparatus 10 as desired or necessary.
It can therefore be seen that first means 12 is attachable onto an object or item such as, for example, a belt, a cap visor, or an article of clothing, while allowing for the directional adjustability of laser diode module 14 in any direction as shown in FIG. 1 .
Referring also to FIG. 2 and FIG. 3, a second embodiment 46 of first means 12 for attaching or mounting a laser diode module 14 , in accordance with the present invention, is generally shown. Second embodiment 46 of first means 12 for attaching or mounting laser diode module 14 comprises a planar strip 48 having a first edge 50 , a second edge 52 , and a center section 54 . Center section 54 is curved over such that first edge 50 is disposed generally adjacent second edge 52 . First edge 50 , second edge 52 , and center section 54 define a gap 56 that tapers from center section 54 towards both first edge. 50 and second edge 52 . Second edge 52 slightly away from first edge 50 to facilitate the insertion of an object therebetween.
In second embodiment 46 of first means 12 for attaching or mounting a laser diode module 14 , second means 16 for adjusting laser diode module 14 may also include a first hinge assembly 38 . First hinge assembly 38 is capable of pivoting around a first axis “x” and may be glued-of otherwise integrally molded to second embodiment 46 of first means 12 for attaching or mounting a laser diode module 14 . First hinge assembly 38 is secured onto laser diode module 14 by a tab (not shown) inserted into laser diode module 14 or otherwise integrally molded thereto.
It can be seen that second embodiment 46 of first means 12 for attaching or mounting a laser diode module 14 is attachable onto an object or item of apparel, such as, for example, a belt 58 . It is also contemplated that second embodiment 46 of first means 12 for attaching or mounting a laser diode module 14 is also attachable onto, a cap (not shown), or an article of clothing, while allowing for the directional adjustability of laser diode module 14 in any direction around a single axis.
Referring also to FIG. 4 and FIG. 5, a third embodiment 60 of first means 12 for attaching or mounting a laser diode module 14 , in accordance with the present invention, is generally shown. Third embodiment 60 of first means 12 comprises a strip 62 having a first end 64 and a second end 66 . Strip 62 is curved such that a generally circular opening 68 is formed therein. Strip further comprises a first tang 70 and a second tang 72 . First tang 70 extends outwardly from first end 64 of strip 62 , while second tang 72 extends outwardly from second end 66 of strip First tang 70 and second tang 72 are generally parallel to each other and incorporate a bolt means 74 for holding tangs 70 and 72 is a fixed position relative to each other. In third embodiment 60 of first means 12 , adjustment mechanism 16 may also include ball and socket joint 38 . Ball and socket joint 38 is connected to third embodiment 60 of first means 12 by a bolt or screw 76 .
It can be seen that third embodiment 60 of first means 12 is ideally adapted for attachment around a generally linear object, such as a pole 77 or the like, and tightening bolt means 74 reduces the area of opening 68 to secure strip 62 onto such object.
Referring also to FIG. 6, a fourth embodiment 78 of first means 12 for attaching or mounting a laser diode module 14 , in accordance with the present invention, is generally shown. Fourth embodiment 78 comprises a first strip 80 and a second strip 82 . First strip 80 includes a first end 84 and a second end 86 , and second strip 82 includes a third end 90 and a fourth end 92 . First strip 80 is curved such that a generally semi-circular opening 94 is formed between first end 84 and second end 86 . Similarly, second strip 88 is curved such that a generally semi-circular opening 96 is formed between third end 90 and fourth end 92 . A first tang 94 and a second tang 96 extends outwardly from first end 84 and second end 86 , respectively, of first strip 80 . Third tang 98 and fourth tang 100 extends outwardly from third end 90 and fourth end 92 , respectively, of second strip 82 . First strip 80 is oriented relative to second strip 82 such that first tang 94 and third tang 98 are adjacent and generally parallel to each other and second tang 96 and fourth tang 100 are adjacent and generally parallel to each other. In order to maintain first strip 80 and second strip 82 in a fixed position relative to each other, fourth embodiment 78 of first means 12 for attaching or mounting a laser diode module 14 further includes a first bolt means 102 and a second bolt means 104 . First bolt means 102 threadably engages first tang 94 and third tang 98 , while second bolt means 104 threadably engages second tang 96 and fourth tang 100 , such that tightening first and second bolt means 102 and 104 draws and compresses first strip 80 and second strip 82 together.
In fourth embodiment 78 of first means 12 , second means 16 for adjusting laser diode module 14 may also include ball and socket joint 38 . Ball and socket joint 38 is connected to fourth embodiment 78 of first means 12 by a bolt or screw 106 . It can be seen that fourth embodiment 78 of first means 12 is also ideally adapted for attachment around a generally linear object, such as a pole or the like.
Referring also to FIG. 7 and FIG. 8, a fifth embodiment 107 of first means 12 for attaching or mounting laser diode module 14 , in accordance with the present invention, is generally shown. Fifth embodiment 107 of first means 12 comprises an upper plate 108 , a lower plate 110 , and a center plate 112 . Center plate 112 is integral to and attached to both upper plate 108 and lower plate 110 wherein a generally rectangular opening 114 is defined between upper plate 108 and lower plate 110 . Upper plate 108 , lower plate 110 , and center plate 112 , each includes a hole 116 a , 116 b , 116 c , respectively, disposed therethrough. It can be seen that fifth embodiment 107 of first means 12 for attaching or mounting a laser diode module 14 is ideally adapted for attachment onto an edge of a planar surface, such as a table 117 or the like. A bolt 118 in conjunction with a clamping member 120 allows fifth embodiment 106 of first means 12 to be securely fastened onto the edge of an object.
In fifth embodiment 106 of first means 12 for attaching or mounting a laser diode module 14 , second means 16 for adjusting laser diode module 14 may also include ball and socket joint 38 . Ball and socket joint 38 is connected to fifth embodiment 106 of first means 12 by a bolt or screw 122 threaded through either hole 116 a or hole 116 b , depending on whether ball and socket joint 38 is positioned on upper plate 108 or center plate 112 , respectively.
Referring also to FIG. 9, a sixth embodiment 124 of first means 12 for attaching or mounting a laser diode module 14 , in accordance with the present invention, is generally shown. Sixth embodiment 124 of first means 12 comprises a housing 126 and a magnet 128 . Magnet 128 is located within housing 126 such that a significant surface area of magnet 128 is exposed for attracting onto a ferrous surface, such as a refrigerator (not shown) or an automobile body (not shown).
In sixth embodiment 124 of first means 12 for attaching or mounting a laser diode module 14 , second means 16 for adjusting laser diode module 14 may also include ball and socket joint 38 . Ball and socket joint 38 is connected to sixth embodiment 124 of first means 12 by threading into or gluing ball and socket joint 38 to housing 126 . Other means of connecting ball and socket joint 38 to housing 126 are contemplated, such as but not limited to, integrally molding or casting.
Referring also to FIG. 10, a seventh embodiment 130 of first means 12 for attaching or mounting a laser diode module 14 , in accordance with the present invention, is generally shown. Seventh embodiment 130 of first means 12 comprises a plate 132 , a support member 134 , and a screw means 136 . Plate 132 includes an upper surface 138 is and an outer end 140 . Support member 134 is integrally coupled to upper surface 138 of plate 132 and extends perpendicularly from outer end 140 thereof. Screw means 136 is disposed through plate 132 and is adapted for threading into an object for attaching seventh embodiment 130 thereto. Another means for attaching screw means 136 to an object is shown and described later. In seventh embodiment 130 of first means 12 for attaching or mounting a laser diode module 14 , second means 16 for adjusting laser diode module 14 may also include ball and socket joint 38 .
Referring also to FIG. 11 and FIG. 12, first hinge assembly 58 is generally shown in combination with seventh embodiment 130 of first means 12 for attaching or mounting a laser diode module 14 . First hinge assembly 58 may be connected to plate 132 of seventh embodiment 130 for attaching a laser diode module 14 , by welding, gluing, integrally molding, or the like. First hinge assembly 58 may also be connected to second embodiment 46 for attaching a laser diode module 14 .
It can be seen that seventh embodiment 130 of first means 12 for attaching or mounting a laser diode module 14 may be attached to a cap 141 wherein plate 132 is slidably engaged within a clip 142 affixed onto cap 141 . Clip 142 includes a narrow channel 143 that receives screw means 136 and imposes compressive force thereon to hold plate 132 within clip 142 . Attachment mechanism 18 for securing first hinge assembly 58 to laser diode module 14 comprises a pair of plates 144 a and 144 b disposed in a generally parallel fashion so as to accommodate laser diode module 14 placed therebetween. A bolt or screw 145 is threaded through plate 144 B and into laser diode module 14 . First hinge assembly 58 allows for the directional adjustability of laser diode module 14 by providing pivotability of laser diode module 14 around axis “x”.
Referring also to FIG. 13 and FIG. 14, a third embodiment 146 of second means 16 for adjusting laser diode module 14 , in accordance with the present invention, is generally shown. Third embodiment 146 of second means 16 for adjusting laser diode module 14 comprises first hinge assembly 58 and a second hinge assembly 147 attached to first hinge assembly 58 by a post 148 . Second hinge assembly 147 resides within housing 126 and is capable of pivoting around a second axis “y” that is perpendicular to axis “x” that first hinge assembly 58 pivots around. It can be seen that third embodiment 146 of second means 16 for adjusting laser diode module 14 provides for adjustment of laser diode module 14 around two perpendicular axes of rotation, “x” and “y”.
Referring also to FIG. 15 and FIG. 16, a fourth embodiment 150 of means 16 for adjusting a laser diode module 14 , in accordance with the present invention, is generally shown. Fourth embodiment 150 of means 16 for adjusting a laser diode module 14 is shown connected to second embodiment 46 of means 12 for attaching or mounting laser diode module 14 . Fourth embodiment 150 of means 16 for adjusting a laser diode module 14 comprises ball and socket joint 38 attached to first hinge assembly 58 by a post 152 .
It may be seen that second embodiment 46 of means 12 for attaching or mounting laser diode module 14 may be attached to a cap 141 by inserting the visor 154 between first edge 50 and second edge 52 and sliding visor 154 through gap 56 . It may be further seen that fourth embodiment 150 of means 16 for adjusting a laser diode module 14 allows for an increased range adjustability of laser diode module 14 since laser diode module 14 may swivel with ball and socket joint 38 while ball and socket joint 38 may pivot around axis “x” of first hinge assembly 58 .
Accordingly, it will be seen that this invention provides for attaching or mounting a laser diode module that enables the laser diode module to be aimed or pointed at a specified location while the laser diode module is either attached to some item of apparel worn by the user or mounted on an object. Although the description above contains much specificity, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Thus the scope of this invention should be determined by the appended claims and their legal equivalents. | A laser diode module attachment and mounting apparatus for adjustably mounting a laser diode module onto a fixed object, such as a pole, table edge, or refrigerator or the like, or an item of apparel, such as a cap, belt, pants, shirt or the like, thereby enhancing not only the practical applications for the Laser Diode, but also furthering its entertainment appeal. The laser diode module attachment and mounting apparatus allows for aiming, and hence projecting, a laser image on a desired target while the laser diode module is either attached to an item of apparel worn by the user or mounted onto an object. The apparatus generally comprises a first means for attaching a laser diode module onto an object, a second means for adjusting a laser diode module, and an attachment mechanism for securing the laser diode module onto the second adjusting means. The second adjusting means allows for rotation, and hence, aiming of the laser diode module around one rotational axis or around a plurality of rotational axes. The abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. | 5 |
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to an improved cigarette filter with a scavenging effect on gas phase free radicals in cigarette smoke. The invention uses filters that contain proanthocyanidins for scavenging the free radicals. The present invention is also directed to a method for producing an improved cigarette filter with scavenging effect on gas phase free radicals.
It is well accepted that lit cigarettes produce an enormous amount of free radicals, including gas phase and solid phase free radicals. The number of free radicals in the gas phase has been estimated to be 10 15 per puff, which are primarily alkyl, alkoxyl, peroxyl and nitric oxide (NO.) free radicals. Inhaling the gas phase free radicals produced by cigarette smoke into a human body is known to produce toxicological and pathological changes that are deleterious to humans. The gas phase free radicals are widely known to be more harmful to the human body than are solid phase free radicals. In part, this is a result of the high energy levels, that is, the volatility of gas phase free radicals.
Cigarette combustion, in particular, involves a complex burning process which produces free radicals that exist in the smoke. Cigarette smoke is a complex mixture of more than 4,700 chemicals, including high concentrations of highly reactive free radicals which play a major role in the toxicity of the smoke. The free radicals attack cell constituents, either directly or indirectly, and are believed to be a factor in tobacco smoke related diseases. Many parts of the body may be adversely affected by the gas phase free radicals including the lungs, mouth, pharynx, esophagus, heart and circulatory systems, and various organs. Free radicals may change the molecular structures of cell proteins and lipids and cause breaks in DNA sequences that lead to mutations, thereby increasing the risks of developing various types of cancers.
Studies indicate that mainstream smoke, that is, smoke inhaled directly from a lit cigarette and sidestream smoke, which is smoke emitted from the smoldering tobacco between puffs and through the exhaled smoke emitted by a smoker, contain high concentrations of free radicals. Sidestream smoke affects both the smoker and the non-smokers around the smoker. A major health concern relates to the exposure of non-smokers, including infants and children, to tobacco smoke in the home and other locations that derives from smokers. Individuals who do not smoke but are exposed to secondary sidestream smoke may suffer the consequences of free radical damage from tobacco smoke.
Most of the free radicals in burning cigarette-produced smoke gas phase are instantaneous and unstable. It is impossible to observe them directly with Electron Spin Resonance Spectroscopy (“ESR spectroscopy”) techniques. In order to observe gas phase free radicals, such as those present in cigarette smoke, a spin capture technique is employed. In this technique, gas phase free radicals are captured and then transformed into a spin adduct which can be tested via ESR spectroscopy. A spin collector (PBN) collects smoke gas phase free radicals, which are predominantly alkoxyl free radicals (RO.) and alkyl free radicals (R.).
Most of the gas phase free radicals in tobacco smoke are RO. and alkyl R. free radicals. Nitrogenous substances oxidize and produce great amounts of NO free radicals (NO.) in the process of cigarette burning. A reaction of NO. with oxygen results in the production of reactive NO 2 . free radicals. A NO 2 . free radical may react with olefin, a substance produced during cigarette burning, to form alkyl free radical RO. RO. free radicals may attack cell membranes and cause lipid peroxidation. In turn, such lipid peroxidation may stimulate macrophages to release oxygen free radicals. Oxygen free radicals, on their own, may independently cause injury to cell constituents. They may poison cells and may contribute to causing lung cancer and heart disease together with the free radicals present in the smoke of a lit cigarette. Such free radicals may also attack and, thereby inactivate pulmonary ∝-1 antiprotease, which inhibits elastase and hence causes pulmonary injury.
Also, free radicals from cigarette smoke are considered in the pathogenesis of smoking-induced lung diseases, such as emphysema, lung cancer and heart diseases. Components of the lung matrix itself (e.g. collagen, elastin) can be damaged and fragmented by oxidants in cigarette smoke.
The damage of free radicals from cigarettes is not limited to the pulmonary tract. It was found that the urine of smokers contains 10 fold higher amounts of a typical biomarker of oxidative damage than the amounts shown in the urine of non-smokers. The noxious pro-oxidant effects of smoking may even extend beyond the epicardial arteries to coronary microcirculation and affect regulation of myocardial blood flow and cause carotid-media thickness.
One filter that claims to scavenge free radicals in cigarette smoke was pursued jointly by Biophysics Institute of Academica Sinica and Beijing Cigarette Factory in 1995. It uses tea polyphenol, vitamin C, and active carbon for a compound filter. This filter scavenges approximately 14% of gas phase free radicals caused by tobacco smoke. If additional ingredients, including ematin, rutin, catechin and neo-rutin are added to the tobacco in the cigarette, approximately an additional 12% of the gas phase free radicals may be scavenged. These additional ingredients, in combination, are referred to as “kendir” and “apocynum venetum L”. Another cigarette filter that scavenges for free radicals was jointly invented by the Greece Golden Filter Company and Filter Development Company in 1999 (the “jointly developed filter”). This filter comprises active carbon and hemoglobin. It claims to scavenge about 90% gas phase free radicals found in tobacco smoke. Neither one of these two filters has gained commercial acceptance by cigarette manufacturers. There are two major reasons for the poor commercial acceptance of these filters. One is that the large dosages of additives in these filters reduce the original smoke flavor of the cigarette. This is a very significant disadvantage in the cigarette industry where cigarette taste and flavor is a key selling feature of recognized cigarette brands. Another factor is that the production of these complex filters requires a large investment in equipment modification which cigarette manufacturers are reluctant to invest. Another filter disclosed in U.S. Pat. No. 5,829,449 is directed to using L-glutathione and a source of selenium as the radical scavenger complex ingredient.
Accordingly, there is a need for: i) a cigarette filter with good scavenging effect on gas phase free radicals in cigarette smoke; ii) a cigarette filter that scavenges gas phase free radicals in cigarette filters and does not significantly alter or reduce the flavor and taste of the cigarette; and iii) a cigarette filter containing free radical scavengers that are optimally exposed to cigarette smoke in order to yield a maximum scavenging effect in a short period of time.
BRIEF SUMMARY OF THE INVENTION
One aspect of the invention resides in an improved cigarette filter with a scavenging effect on smoking induced gas phase free radicals which is achieved through the addition of an effective amount of a filtering ingredient or a mixture of the filtering ingredient and vitamin C and/or other ingredients known in the art having antioxidant filtering properties, but excluding a certain amount of L-glutathione. The filtering ingredient is selected from a group consisting of proanthocyanidins which may include procyanidins. These ingredients include extracts of barks of pine trees, extracts of cones of cypress trees, extracts of grape seeds and any combination thereof.
DETAILED DESCRIPTION OF THE INVENTION
Proanthocyanidins are highly potent free radical scavengers. In particular, proanthocyanidins represent a group of plant polyphenols found in fruits with an astringent taste and in barks. Proanthocyanidins may be extracted from plant material by conventional methods using water, ethanol or acetone/water mixtures as solvents and then concentrated through the processes of solvent evaporation, freeze-drying or spray-drying. Proanthocyanidins include procyanidins and prodelphinidins.
The proanthocyanidin used in the example below is Pycnogenol® pine bark extract which is produced and marketed by Horphag Research Limited. Pycnogenol® pine bark extract is derived from the bark of the French Maritime pine. It contains a range amount of approximately 70%-75% proanthocyanidins and other flavanols with free radical scavenging activity such as catechin, taxifolin and phenolic acids. The proanthocyanidins contained in this extract have a chain length of about 2 to 12 monomeric units, wherein the monomeric units consist of catechin or epicatechin. Other procyanidin-rich substances could also be used as free radical scavengers in cigarette filters. These substances include but are not limited to, extracts of the barks of pine trees, cones of cypress trees or grape seeds. Proanthocyanidins are particularly suitable for cigarette filters because they are non-volatile substances. Proanthocyanidins are biopolymers that possess a great tendency to stay adsorbed and remain inside the filter.
Free radical scavenging filters of the present invention may be prepared by evenly spraying a free radical scavenger solution completely over filter filaments, and then drying the filter elements and connecting the filter elements with cut unfiltered cigarettes and/or cigarette tobacco for forming into cigarettes. Prior to drying, the filter element may be shaped in a filter bundle shaping process.
Several examples of specific free radical solutions may be used. The examples and results are discussed below.
EXAMPLE 1
Dissolve proanthocyanidin and vitamin C (100%) in a proportion of 1:2 into a 95% ethanol solution. Evenly spray the ethanol solution containing the dissolved proanthocyanidin and vitamin C over cigarette filaments. Dry the sprayed filaments thereafter and process the dried filaments into cigarette filters as is well known in the art. Combine same with unfiltered cigarettes. The resulting proanthocyanidin and vitamin C content in such a cigarette filter of this example is respectively equal to about 0.00015% and 0.0003% of the cut tobacco of this cigarette in weight.
Testing for the effectiveness of the improved filter was performed in the following manner. Unfiltered cigarettes were used as reference cigarettes. ESR techniques were used to test the gas phase radicals respectively contained in the smoke of the cigarettes. The amount of free radicals in the filter of the present invention was compared with the amount in standard unfiltered cigarettes. Efficacy of the improved filter was conducted by using a smoking device to imitate human's smoking at a flow rate of about 400 ml/min, inhaling once for two seconds, one minute apart. The ESR testing conditions included: X band, 20 m W microwave power, 100 KHz modulation frequency and 1G modulation amplitude. See Table 1 for the test results. The free radical scavenging rate E was calculated by the following formula:
E=H o ×100 /H x
where H o represents the peak intensity of the reference system, and H x represents the peak intensity of scavenger containing samples. According to this formula, the gas phase free radical scavenging rate E was 24.3%.
EXAMPLE 2
Using the method of Example 1, cigarettes with the improved filter having a proanthocyanidin content of about 0.00015% (based on the weight of a single cigarette of cut tobacco) were tested in accordance with the procedure explained above and calculated by the above-mentioned free radical scavenging rate formula. The gas phase free radical scavenging rate was 22.6%. For the detailed results, see Table 2.
EXAMPLE 3
Using the method of Example 1, the cigarettes with the improved filter having a proanthocyanidin content of about 0.0003% (based on the weight of a single cigarette of cut tobacco) were tested in accordance with the procedure explained above and calculated by the above-mentioned free radical scavenging rate formula. Calculated by the above-mentioned free radical scavenging rate formula, the gas phase free radical scavenging rate was 27.6%. For the detailed results, see Table 3.
EXAMPLE 4
Using the method of Example 1, cigarettes with an improved filter having a proanthocyanidin content of about 0.0005% (based on the weight of a single cigarette of cut tobacco) were tested in accordance with the procedure explained above and calculated by the above-mentioned free radical scavenging rate formula. Calculated by the above-mentioned free radical scavenging rate formula, the gas phase free radical scavenging rate was 29.1%. For the detailed results, see Table 4. This test indicated that when the proanthocyanidin content in the filter is 0.0005%, the gas phase radical scavenging effect is at its maximum.
EXAMPLE 5
Using the method of Example 1, cigarettes with an improved filter having a proanthocyanidin content of about 0.001% (based on the weight of a single cigarette of cut tobacco) were tested in accordance with the procedure explained above and calculated by the above-mentioned free radical scavenging rate formula. Calculated by the above-mentioned free radical scavenging rate formula, the gas phase free radical scavenging rate was about 20%. For the detailed results, see Table 5. As shown by the above examples, when the proanthocyanidin content in the filter is within a range of about 0.00015% and 0.001% (based on the weight of a single cigarette of cut tobacco), a high scavenging effect on gas phase free radicals in smoke was achieved. Adding vitamin C into the filters further improved the free radical scavenging effects.
The reduction of free radicals in tobacco smoke also reduces the mutagenic action of tobacco smoke and markedly increases the life-time of animals exposed to filtered smoke. In one study, mice were exposed to lethal amounts of cigarette smoke in a polyacryl glass cabin (35.6×35×20 cm) with two 1.5 cm 2 holes, one located on top of the cabin for ventilation and another located at the bottom for introducing the gas phase. Forty (40) mice were randomly divided into 4 groups. Mice in group 1 were treated with smoke from cigarettes with standard filters. Mice in groups 2 and 3 were treated with smoke from cigarettes with filters containing 0.00015% mg and 0.0005% mg proanthocyanidin, pine bark extract respectively. Mice in group 4 served as control and were not treated with cigarette smoke. Cigarette smoke was introduced into a cabin containing one group of 10 mice at a time. The time and number of cigarettes used until the lethal endpoint was reached were recorded. The deceased mice were examined for histopathological changes.
All deceased mice were subject to biopsies and histopathological examination. In the control group (cigarette filters without proanthocyanidins) an obvious congestion and hemorrhage in lung tissue was observed in 80% of mice. Also, a vasodilation and congestion of small blood vessels in kidneys and slight vasodilation and congestion of central veins in livers were found. However, there were no visible abnormal changes in the heart and spleen.
The presence of 0.0005% proanthocyanidin pine bark extract in cigarette filters significantly increased the survival time and reduced the acute toxicity of cigarette smoke by 70.5%. In the absence of proanthocyanidins in the cigarette filters, the mice died after inhaling the smoke of 8 cigarettes, wherein the presence of 0.0005% mg proanthocyanidin pine bark extract in the filters, mice died after exposure to the smoke of 14 cigarettes.
Based on the above, the appropriate content of the above-mentioned free radical scavenger contained in a filter shall account for 0.0001%-0.001% of the cut tobacco in weight. The scavenger is more effective in this range. The proportion between the procyanidin content and the vitamin C content is equal to 0.5-1.5:1.5-2.5, and the most preferred is 1.0. In all the embodiments however, L-glutathione and a source of selenium selected from the group consisting of L-selenomethionine and L-selenocysteine are substantially or completely excluded from inclusion in the cigarette filter of the invention.
TABLE 1
0.00015% proanthocyanidin and 0.0003% Vc combining filter's
scavenging effect on gas phase free radical in smoke
H o of control Group
H x of Application Example 1
6.7
18.5
7.6
11.5
4.3
11.4
6.2
5.8
5.6
21.5
7.8
7.7
5.6
10.7
5.8
9.5
5.7
14.2
5.5
10.4
5.7
5.2
4.4
5.9
6.9
21.5
6.0
7.2
5.2
5.5
5.6
5.6
7.0
6.5
7.4
7.2
5.9
4.4
10.5
6.5
7.8
6.4
8.2
5.5
7.0
1.5
6.3
10.4
7.4
6.0
8.0
10.3
6.2
6.7
5.6
7.1
10.0
6.0
9.0
11.0
9.0
6.0
5.5
10.7
8.5
6.7
6.2
12.5
6.7
6.0
5.5
7.3
5.7
6.0
6.2
9.5
5.0
6.7
5.7
9.8
6.7
7.4
6.0
12.6
6.3
5.6
9.0
7.0
6.8
7.8
9.2
9.4
5.2
7.0
10.0
8.0
7.4
8.0
9.5
8.7
7.4
6.0
8.0
6.0
8.0
16.0
8.0
9.8
4.6
5.5
6.8
8.5
7.1
16.0
5.3
6.8
5.0
6.5
7.5
7.2
6.6
17.0
7.3
9.0
5.2
11.8
7.0
6.8
8.9
11.8
8.3
9.6
8.3
11.8
9.1
7.5
9.0
8.0
10.3
8.9
8.2
6.0
6.4
7.0
11.5
9.0
8.1
8.5
8.0
4.0
6.0
6.1
17.0
6.2
9.0
8.8
10.0
5.0
4.5
6.2
7.8
6.0
7.5
9.7
8.4
6.2
7.0
6.7
6.3
9.0
6.5
9.5
6.6
6.1
8.3
7.0
8.8
9.2
11.4
8.9
8.8
11.8
9.8
7.1
12.8
8.7
8.5
9.8
10.5
8.7
6.7
7.2
7.7
8.5
8.7
9.7
7.8
4.3
5.6
6.0
5.7
6.9
7.0
7.8
5.2
5.9
7.0
5.2
7.4
10.0
8.5
9.8
9.0
6.7
5.0
6.2
6.7
6.8
7.4
8.0
5.2
7.4
4.6
6.3
7.1
6.6
8.9
9.0
5.2
8.3
8.2
5.0
11.5
17.0
7.8
10.5
10.0
8.4
4.1
3.5
11.9
12.0
10.8
9.8
7.5
3.5
4.1
4.2
Mean value
8.96
6.73
Standard error
2.59
1.81
Scavenging effect
24.3%
P
<0.01
TABLE 2
0.00015% proanthocyanidin combining filter's scavenging
effect on gas phase free radical in smoke
H o of Control Group
H x of Application Example 2
4.1
4.6
4.5
4.5
2.0
3.0
4.3
5.1
7.5
4.8
8.0
5.0
4.5
7.5
4.7
4.0
4.0
8.0
13.5
8.0
5.0
3.5
9.0
3.5
6.9
6.2
4.7
5.6
7.8
7.9
7.4
5.1
5.7
6.9
7.0
7.8
5.0
3.9
4.9
5.7
7.4
10.0
6.5
5.7
5.1
6.7
7.1
6.6
6.7
6.8
7.4
8.0
7.3
7.0
6.4
6.3
7.1
6.6
8.9
9.0
5.0
6.9
6.1
4.2
11.5
17.0
7.8
7.0
6.5
7.0
10.0
11.0
6.6
7.1
9.0
8.8
11.5
6.2
6.4
6.5
6.3
8.7
7.6
5.0
7.7
8.0
6.0
7.0
7.0
7.5
6.1
5.0
4.1
7.6
5.6
6.0
5.5
5.5
6.5
8.5
7.5
5.0
4.0
4.1
8.5
9.5
8.5
10
4.0
5.0
4.0
4.05
12
9.0
8.0
7.0
4.0
5.5
6.0
4.6
10
11.0
10.5
8.9
7.3
5.5
7.5
7.6
9.2
9.5
10.0
7.0
4.8
5.7
6.0
6.6
10.5
8.0
8.0
5.0
8.0
Mean value
7.22
5.97
Standard error
2.28
1.90
Scavenging effect
22.6%
P
<0.05
TABLE 3
0.003% proanthocyanidin combining filter = s scavenging
effect on gas phase free radical in smoke
H o of Control Group
H x of Application Example 3
18.5
6.5
9.9
5.2
12.0
6.7
5.3
4.4
18.5
6.8
7.3
5.8
12.0
5.6
6.0
2.7
16.5
5.3
7.5
7.2
11.0
6.1
7.5
6.5
15.5
5.9
7.5
9.0
10.3
5.7
6.0
4.2
15.2
5.8
7.0
8.8
10.0
6.7
5.2
6.0
15.0
7.7
6.1
8.5
10.0
7.0
5.4
6.2
15.0
5.5
6.5
7.4
9.9
7.1
4.6
6.1
13.7
5.4
8.0
10.5
9.5
7.8
6.0
7.0
13.3
5.8
6.6
8.0
9.0
7.8
3.0
7.0
13.0
7.8
7.0
6.6
8.2
5.1
4.2
6.1
12.0
6.2
9.0
6.5
8.0
7.1
4.5
3.9
11.2
7.9
8.6
5.7
8.0
5.1
4.0
6.0
10.0
6.0
6.0
7.2
7.0
5.6
3.7
7.2
8.0
6.5
6.5
7.3
6.5
6.8
5.4
6.7
9.0
6.0
5.0
7.8
7.2
4.2
4.2
3.2
7.8
7.1
6.8
7.0
6.0
8.0
6.7
4.1
6.7
6.1
5.9
7.4
7.1
5.3
6.0
4.5
18.5
5.5
14.2
5.5
10.5
11.2
10.5
8.0
6.5
6.4
6.0
6.0
3.6
8.4
5.1
4.7
6.7
6.0
7.4
7.8
4.0
5.5
5.7
4.5
8.0
16.0
16.0
17.0
12.0
10.5
10.5
6.0
11.8
8.0
9.0
9.5
11.8
5.0
5.2
5.0
6.0
7.6
7.8
10.5
7.7
7.0
6.0
5.0
6.0
7.4
8.2
7.9
6.5
3.5
6.0
4.0
6.0
5.0
6.2
9.7
5.2
6.0
8.0
9.0
6.7
5.6
6.0
10.9
6.9
5.6
2.3
5.0
5.7
6.7
7.0
9.8
3.7
6.7
2.7
5.0
7.8
9.8
5.7
8.1
2.0
2.2
6.2
8.2
5.1
8.2
5.6
8.9
3.8
4.6
2.9
6.8
5.3
8.0
7.5
9.0
4.3
2.5
2.6
5.0
6.5
8.8
5.3
9.6
5.2
5.4
4.6
6.0
5.8
7.7
8.5
9.8
3.0
4.2
4.5
5.2
5.8
7.8
6.2
7.9
5.2
3.7
5.4
4.4
9.2
8.0
8.5
9.9
2.7
6.5
4.2
5.0
9.8
8.0
9.5
10.5
6.5
6.1
2.0
4.5
Mean value
8.30
6.01
Standard error
2.92
2.12
Scavenging effect
27.6%
P
<0.01
TABLE 4
0.0005% proanthocyanidin combining filter's scavenging
effect on gas phase free radical in smoke
H o of Control Group
H x of Application Example 4
7.9
15.0
5.8
6.7
5.4
2.0
6.2
6.5
8.7
18.0
5.9
6.0
5.8
10.5
7.0
6.8
9.7
15.0
6.2
7.4
4.9
11.0
6.2
7.0
7.0
19.0
6.1
7.8
7.0
6.6
5.0
7.0
8.6
16.5
5.0
8.0
8.0
10.3
3.5
3.9
8.8
7.3
6.3
16.0
8.0
7.0
6.6
2.5
9.4
8.0
5.2
16.0
8.7
6.0
4.1
8.5
10.1
12.0
7.1
17.0
6.7
8.6
2.6
4.1
7.0
11.2
7.5
11.8
8.7
9.6
2.6
4.8
7.5
13.0
7.6
8.0
6.5
5.8
1.2
5.2
8.7
13.3
6.5
9.0
5.6
1.8
1.9
5.5
9.6
11.2
6.9
6.2
6.7
11.0
5.9
5.0
6.1
18.5
6.8
6.0
7.6
10.7
4.6
6.1
5.9
15.2
5.9
7.6
5.5
9.8
4.0
10.0
6.6
15.5
6.2
7.8
5.5
9.7
4.7
7.4
6.2
10.0
18.5
5.5
6.0
10.0
5.4
10.0
6.3
13.7
21.5
6.0
5.0
9.0
3.0
8.0
7.4
7.2
14.2
7.4
6.7
6.7
6.2
5.0
9.1
6.2
6.5
8.2
6.6
5.0
6.4
8.0
6.4
6.0
6.6
6.0
7.1
5.8
5.6
9.8
5.0
6.2
6.2
6.9
8.8
3.0
4.4
4.5
9.2
9.5
6.0
8.2
5.7
5.8
5.7
8.5
10.3
8.1
9.0
7.5
7.7
9.5
7.5
8.2
7.2
6.2
5.8
5.9
5.0
6.2
7.0
6.2
8.2
8.1
5.0
8.3
5.0
3.5
6.6
4.1
5.3
7.7
7.5
7.6
2.6
2.6
1.2
1.9
8.5
8.9
6.8
4.7
5.9
4.6
4.0
4.7
5.9
6.2
7.9
8.0
5.4
3.0
5.4
5.8
9.7
7.0
8.6
8.0
4.9
7.0
6.0
6.0
8.8
8.2
10.1
7.0
6.2
6.7
6.7
6.7
7.5
8.7
9.6
6.1
6.5
5.6
6.7
7.6
5.9
8.6
6.2
6.3
5.5
5.5
6.0
5.0
7.4
9.1
6.7
6.6
Mean value
8.62
6.11
Standard error
3.39
2.17
Scavenging effect
29.1%
P
<0.01
TABLE 5
0.001% proanthocyanidin combining filter = s scavenging
effect on gas phase free radical in smoke
H o of control Group
H x of Application Example 5
6.6
8.5
7.8
6.6
1.2
6.5
5.8
1.2
6.6
6.0
8.0
5.6
5.8
6.0
11.1
5.9
8.6
5.4
16.0
8.6
4.0
4.8
12.0
4.0
6.9
6.1
16.0
5.9
4.9
7.2
11.8
4.9
5.8
6.1
17.0
5.3
5.2
6.2
11.0
5.2
6.4
7.8
11.8
6.4
4.5
6.6
12.5
4.5
7.1
7.8
8.0
5.1
8.0
5.7
9.0
6.0
8.2
5.7
9.0
8.2
6.2
4.7
6.7
6.2
6.3
6.0
6.2
6.3
5.9
5.0
5.2
5.9
6.7
8.5
6.0
8.1
5.2
6.0
7.0
5.2
5.7
8.0
7.6
5.2
5.2
6.0
7.0
5.3
6.9
5.3
7.8
6.9
5.1
6.3
6.5
5.1
6.2
5.8
5.5
6.2
5.1
2.7
4.0
5.1
7.8
7.1
6.0
8.8
6.0
6.0
8.0
6.0
6.8
7.2
7.4
8.8
4.0
6.9
5.0
4.0
5.8
5.9
8.2
8.6
5.6
2.9
5.4
5.6
6.7
6.5
6.0
8.1
4.1
7.0
5.5
4.1
5.7
8.1
5.0
5.2
4.7
5.8
5.0
4.7
5.6
5.0
6.2
5.0
5.0
6.0
4.3
5.2
5.9
6.5
6.2
6.7
5.2
4.3
5.0
5.2
5.9
6.0
6.0
5.4
5.6
5.7
9.5
5.1
7.2
6.5
9.2
5.7
4.3
5.0
10.7
5.1
7.5
6.7
9.5
5.6
4.9
6.6
9.5
4.4
6.5
18.5
6.0
5.9
4.9
12.5
7.5
5.0
6.7
21.5
5.3
7.2
6.1
10.7
8.2
5.2
7.3
14.2
7.3
7.5
5.8
11.5
8.0
5.6
7.6
21.5
8.2
6.5
7.7
8.7
6.0
4.3
5.8
6.5
10.3
6.7
6.1
4.8
6.4
4.9
6.4
6.4
8.1
7.3
5.6
2.0
4.9
6.0
6.6
6.0
9.0
7.6
4.9
6.0
5.8
5.6
6.3
6.0
7.4
7.8
6.5
5.6
7.1
6.1
7.3
6.7
6.7
7.8
7.1
4.0
5.6
4.9
7.8
6.0
6.0
8.5
7.1
6.0
3.5
6.0
Mean value
7.45
5.96
Standard error
2.79
2.02
Scavenging effect
20.0%
P
<0.05 | A cigarette filter that has a scavenging effect on smoking induced gas phase free radicals. The filter ingredients are comprised of proanthocyanidins and include, but are not limited to, extracts of barks of pine tree, extracts of cones of cypress trees, extracts of grape seeds, and any combination thereof. Also, vitamin C and other known antioxidant ingredients may be added. | 0 |
The United States Government has a paid-up license in this invention and the right in limited circumstances to require the patent owner to license others on reasonable terms as provided for by the terms of Contract No. 9-XQ2-Y1169-1, awarded by the Department of Energy.
This is a continuation of U.S. patent application Ser. No. 08/283,399, filed Jul. 29, 1994, now abandoned.
BACKGROUND--FIELD OF INVENTION
This invention relates to downhole acoustic sources, specifically to such acoustic sources which can be used for cleaning oil, gas, and water wells, wellbores, perforations, and near wellbore formation damage.
BACKGROUND--DESCRIPTION OF PRIOR ART
The productivity of oil and gas wells declines with time to various reasons. Some of these reasons are: plugging of pores in the rock by mineral "fines" that flow with the produced fluids, precipitation of inorganic scales, paraffin and asphaltene deposition, clay swelling, invasion of mud solids and mud filtrate, invasion of completion fluids, and solids from injected brines. Each of the above reasons can cause a decline in the permeability of the region around the wellbore or a restriction to flow in the wellbore itself.
Periodic stimulation of oil and gas wells is routinely conducted using three general types of treatments: acidizing, fracturing and solvent/heat treatments. Acidizing involves the use of mixtures of hydrochloric (HCL) and hydrofluoric acid (HF) that are injected into the producing payzone (rock). The acid is designed to dissolve the reactive components of the rock (carbonate and clay minerals and to a lesser extent silica) and increase its permeability. Additives such as corrosion inhibitors and solvents are often added to enhance the performance of the acid job. While acidizing is a common treatment for stimulating oil and gas wells it has some clear drawbacks. It is expensive because of the chemical costs and waste disposal costs involved. Acids are often incompatible with the crude oil and can result in thick oily sludges downhole. Precipitates formed after the acid is spent can often be more damaging than the minerals dissolved. The depth of penetration of the live acid is usually less than 3" to 5".
Hydraulic fracturing is another technique that is commonly used to stimulate oil and gas wells. In this process large hydraulic pressures are used to create vertical fractures in oil and gas bearing rock. The fractures can be packed with proppant (in sandstones) or etched with acid (in carbonates and other soft rock) to create a conduit for oil and gas to flow into the wellbore. This process is extremely expensive (about a factor of five to ten more than an acid job). In some cases the fracture can extend into water bearing zones increasing the amount of water being produced (undesirable). Such treatments extend several hundred feet away from the wellbore and are more commonly used in low permeability rocks. The ability to place proppant successfully in the entire fracture is usually limited and problems such as fracture closure and proppant crushing can severely impair the productivity of hydraulic fractures.
One of the most common problems in mature oil wells is the precipitation of paraffins and asphaltenes in and around the wellbore. Steam or hot oil is injected into the wellbore to melt the paraffins redissolve them in the oil and flow them to the surface. Organic solvents (such as xylene) are often used to remove asphaltenes that have a high melting point and are insoluble in alkanes. Steam or solvent soaks both expensive (solvents more so than steam) particularly when treating marginal wells producing less than 10 bbls of oil per day. It should be noted that there are over 100,000 such wells in Texas alone.
A major limitation in steam or solvent soaks is the lack of mechanical agitation that is required to redissolve or resuspend the paraffins and asphaltenes.
Downhole tools that create pressure pulses and can be used for cleaning have been proposed earlier. For example in U.S. Pat. No. 3,721,297, to R. D. Challacombe, a series of explosive caps and gas producing modules are interconnected on a single string so that burning one ignites the others in succession. The explosions create shock waves that were claimed to clean wells. This method has distinct disadvantages, i.e. the potential hazards of damaging high pressure oil and gas wells with explosives. In addition the risk of fire and lack of control on treatment time make this an impractical method.
U.S. Pat. No. 3,648,769 to Mr. H. T. Sawyer describes a hydraulically driven diaphragm that creates "sinusoidal vibrations in the low sonic range." The waves generated are low intensity and are not directed or focused at the face of the rock. As a result much of the energy propagates along the borehole.
U.S. Pat. No. 4,343,356 to E. D. Riggs et al. describes an apparatus for treating subsurface boreholes. Application of a high voltage results in the generation of a voltage arc which dislodges scale material from the walls of the borehole. This is an entirely different method for cleaning than is proposed here. It is not clear if this arcing can be conducted continuously as the sonde is pulled out of the hole or if any cleaning is affected. Safety (electrical and fire) remains a major concern.
Another hydraulic/mechanical oscillator was proposed by A. G. Bodine (U.S. Pat. No. 4,280,557). Hydraulic pressure pulses created inside an elongated elastic tube is used to clean the walls of the casing in wells. This also suffers from being low intensity and poorly directed.
Finally a method for removing paraffin from oil wells was proposed by J. W. Manus (U.S. Pat. No. 4,538,682). The method is based on establishing a temperature gradient in the well by introducing a heating element in the well.
None of the patents listed above propose any device or are based on any principle used in the present invention.
OBJECTS AND ADVANTAGES
Several objects and advantages of the present invention are:
a) To provide a downhole acoustic source that generates extremely high energy acoustic waves that are capable of removing "fines", scales and organic deposits both in and around the wellbore.
b) To provide a downhole acoustic source that does not require the injection of any chemicals to stimulate oil and gas wells.
c) To provide a downhole acoustic source that does not have any environmental treating costs associated with fluids flowing back from the well after treatment.
d) To provide a downhole acoustic source that can be run through 111/16" tubing without having to pull the tubing.
e) To provide a downhole acoustic source that can be run in any type of completion hole, cased/perforated hole, gravel packed, screens/liners, etc.
f) To provide a downhole acoustic source that can be run in conjunction with other chemical stimulation treatments such as solvent soaks, acidizing, etc.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objects and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
FIG. 1. a drawing showing the functional elements in the tool.
FIG. 2. a graph showing the sound intensity produced by various diameter tools on the surface of the borehole as a function of borehole diameter.
FIG. 3. a drawing showing the preferred embodiment of the transducer.
FIG. 4. a drawing showing one embodiment of the head mass.
FIG. 5. a drawing showing a second embodiment of the head mass.
FIG. 6a. is a drawing of one configuration of the transducer array.
FIG. 6b. is a sectional view of the configuration of the transducer array of FIG. 6a, taken along line A--A'.
FIG. 6c is a sectional view of the configuration of the transducer array of FIG. 6a taken along B--B'.
FIG. 7. is a pictorial representation of the acoustic cleaner of the present invention used to clean a cased or open borehole.
FIG. 8. is a pictorial representation of the acoustic cleaner in a different configuration used to clean a sand screen in a well with production tubing installed.
REFERENCE NUMERALS IN DRAWINGS
10 86 mm Diameter tool
12 wireline cable
16 up hole power supply
18 down hole power supply
20 logic circuit
22 continuous sine wave
24 burst waveform
26 power amplifier
28 transducer
30 centralizers
32 vertical axis on graph
34 Borehole diameter axis
36 power for 86 mm diameter tool
38 power for 64 mm diameter tool
40 power for 43 mm diameter tool
42 shaded portion of graph
44 ceramic element
46 ceramic element
48 head mass
50 face of head mass
52 "O" ring seal groove
54 bolt
56 positive electrode of ceramic
58 ground electrode
60 center electrode
62 insulator
64 washer
66 flat washer
68 tension member
70 compression member
72 space behind transducer
74 cased hole
76 perforation
78 producing zone
80 43 mm diameter tool
82 sand screen
84 production tubing
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The functional elements of the tool are shown in FIG. 1. A tool 10 is lowered into a well via a wireline cable 12. Power is supplied to electronics via this cable from a power supply located uphole 16. An electronics package performs several functions. A power supply 18 provides regulated voltages to the various functional units. A logic circuit 20 controls a transmit frequency and a modulation signal applied to transducers. Transducers 28 may be driven with a continuous sine wave 22 or may be pulsed on and off rapidly 24. The modulation of the signal allows for a pulse power greater than the average power. A logic circuit 20 creates the proper signal with which to drive power amplifiers 26. Power amplifiers convert the power supplied by a cable to a high frequency signal 20 kHz to 100 kHz which drives the acoustic transducers 28. The tool may have from 1 to 36 individual transducers depending upon the power capability of the cable and the size of the tool. Centralizers 30 are used to maintain the tool in the center of the borehole or tubing.
Since the tool is designed to use multiple small transducers, it is possible to easily configure the basic design into tools having various diameters. Increasing the diameter of the tool allows placing more transducers around the circumference of the tool. FIG. 2 shows the acoustic intensities produced by various diameter tools used in various diameter wells. The vertical axis 32 is the acoustic intensity in watts per square meter. The horizontal axis 34 is the borehole diameter. The three curves 36, 38, 40, are the intensities created by three tool sizes. The limit on acoustic intensity is based upon the mechanical configuration of the transducers in the tool body and the level of power which may be delivered down the particular wireline cable used. The shaded portion of the graph 42 shows the intensity levels at which significant cleaning has been obtained in experimental work. This graph shows that even the smallest tool provides power levels adequate to clean a 203 mm diameter borehole.
A thorough discussion of the design of this type of transducer has been published by M. Ward Widener, "The Development of high efficiency narrow-band transducers and arrays", Journal of the Acoustical Society of America Vol. 67, Mar. 3, 1980, pg. 1051-1057. Another related article by the same author, "The development of a deep submergence, air-backed transducer", J. Acoust. Soc. Am. 80, Dec. 6, 1986, pg. 1852-1853 further describes the construction process for the type transducer used in this tool. A preferred design of the transducer is shown in FIG. 3. Ceramic elements 44 and 46 form half of the Tonpilz resonator, a metal head mass 48 forms the other half. The face 50 of the head mass 48 is machined slightly convex so as to produce a constant sound pressure level across the surface. Included in the horn is an "O" ring seal groove 52 which may be utilized with an "O" ring to sew the ceramic from the borehole fluid. A bolt 54 is used to clamp the assembly together. By assembling the two ceramic elements with the+electrodes 56 in the center, the head mass and the bolt may be held at ground potential. A ground electrode 58 is connected at the head of a bolt. This makes it convenient for the tool to also be at ground potential. The power amplifier is connected to a center electrode 60. An insulator 62 is required on the shaft of the bolt. This insulates the bolt from the center of the two ceramic elements. A washer 64 is machined so as to distribute the pressure of the bolt evenly across the surface of the ceramic. It is also well known in the art that this washer may be much greater in mass. A second flat washer 66 is used to protect the ground electrode. The mass cone and support and fluid seal may be made from a single piece of material. FIG. 4 shows the support having a tension member 68. In like manner, FIG. 5, the support may also be designed to utilize a compression member 70 to support the hydrostatic load. The method of support has little effect on the performance so long as it is affixed at the node of the resonance. The individual transducers are complete functioning parts, they may be individually tested outside of the tool or replaced when necessary. One transducer design may be used in many different size tools.
FIG. 6a shows the method for mounting the transducer in an 86 mm diameter tool 10. A ring of 4 transducers 28 is located at each level in the tool. This drawing shows 9 rings of transducers with each ring rotated by 45 degrees from its most adjacent ring. FIG. 6b shows a cross section of one ring of transducers. A space 72 behind the transducers contains air at atmospheric pressure and allows for electrical connections to be made to the ceramic elements 44 and 46. FIG. 6c shows an adjacent ring to the one shown in FIG. 6b. This ring is rotated 45 degrees from the adjacent ring. This arrangement of the transducers maximizes the density of the transducers in the tool thereby maximizing the acoustic intensity at the location of the transducers.
OPERATION
The tool is used as if it were a standard wireline tool FIG. 7. The tool is maintained in the central portion of the well using two centralizers 30. This tool 10, utilizes 36 transducers 28. It is lowered into the well using a wireline truck and cable. Once it is at the proper depth, power is supplied to the tool and it is pulled upward through the producing zone. FIG. 7 shows 86 mm diameter tool used in a cased hole 74 having perforations 76 in a producing zone 78. The tool may be pulled past the perforations slowly several times or left at a specific depth for a short period of time and then moved upward in short steps. This is a much simpler and cheaper operation that the previously used treatment techniques.
FIG. 8 shows a 43 mm diameter tool 80 used when production tubing is in the well. The operation of the tool is the same as for the large diameter tool. In the typical application, a sand screen 82 used in the tubing becomes clogged with fines or with paraffin. The array of 8 transducer elements 28 is arranged in a helix around the tool. The centralizers 30 maintain the tool near the center of the production tubing 84. The great advantage of this tool is that the production tubing need not be pulled to treat the sand screen 82.
Although the invention has been described with reference to a specific embodiment, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiment as well as alternative embodiments of the invention will become apparent to persons skilled in the art upon reference to the description of the invention. It is therefore contemplated that the appended claims will cover any such modifications or embodiments that fall within the true scope of the invention. | A method and apparatus are disclosed for cleaning the wellbore and the near wellbore region. A sonde is provided which is adapted to be lowered into a borehole and which includes a plurality of acoustic transducers arranged around the sonde. Electrical power provided by a cable is converted to acoustic energy. The high intensity acoustic energy directed to the borehole wall and into the near wellbore region, redissolves or resuspends the material which is reducing the permeability of the formation and/or restricting flow in the wellbore. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Divisional Application of U.S. application Ser. No. 11/746,566, filed May 9, 2007, which claims priority to Korean Patent Application No. 2006-0042031 filed in Korea on May 10, 2006, the contents of which are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] Field of the Invention
[0003] The present invention relates to a method of gap-filling used for fabricating a semiconductor device, and more particularly, to a gap-fill method using an amplitude modulation radiofrequency (RF) power and an apparatus for the same.
[0004] 2. Discussion of the Related Art
[0005] There are many trenches and holes (or gaps) to be filled up when forming separating layer between elements, an inter metal dielectric (IMD) layer and an interlayer dielectric (ILD) layer in a fabricating process of a semiconductor device. Recently, since a density of semiconductor device increases and a width of a metal line and a distance between devices decrease, widths of the trenches and gaps decrease. As a result, there is requirement to be improved in a gap-fill process.
[0006] There are many methods for gap-filling. Among these gap-filling methods, since high aspect ratio is required, a high density plasma chemical vapor deposition (HDPCVD) method has been widely because of excellent gap-fill characteristics. In the HDPCVD method, the gaps are filled up using high density plasma.
[0007] FIG. 1 is a schematic cross-sectional view showing a conventional high density plasma chemical vapor deposition (HDPCVD) apparatus. As shown in FIG. 1 , a conventional HDPCVD apparatus 10 includes a chamber 11 a susceptor 12 , a gas injector 13 , a RF antenna 14 , a source RF power supply 15 , a bias RF power supply 17 and a direct current (DC) power supply 20 . The chamber 11 has an inner reactive space. An insulating plate 21 , which isolates an inner space of the chamber 110 from an outer space, is disposed on an upper wall of the chamber 11 . The susceptor 12 is disposed in the chamber 11 . A substrate “w” is loaded on the susceptor 12 . The gas injector 13 is disposed on opposite side walls of the chamber 11 and around the susceptor 12 . The gas is injected into the chamber 11 through the gas injector 13 . The RF antenna 14 is disposed over the chamber 11 and functions as a plasma injecting source. The RF antenna 14 is connected to the source RF power supply 15 . The bias RF power supply 17 , which controls an energy density of ion supplied onto the substrate “w”, is connected to the susceptor 12 . Generally, a power frequency of the source RF power supply 15 may be one of 400 KHz, 2 MHz, 13.56 MHz and more than 27.12 MHz. A power frequency of the bias RF power supply 17 may be one of 13.56 MHz or less than 2 MHz. A source matching circuit 16 and a bias matching circuit 18 are respectively connected to the source RF power supply 15 and the bias RF power supply 17 to matches impedances. In addition, a direct current (DC) electrode 19 is formed in the susceptor 12 to be closet the substrate to the substrate 12 using a static electricity. The DC electrode 19 is formed of a metallic material such as tungsten (W). The DC electrode 19 is connected to a DC power supply 20 .
[0008] A gap-filling process in the above-mentioned HDPCVD device 10 is explained.
[0009] A substrate “w” is loaded on a susceptor 12 , and inert gases are injected into the chamber 11 . And then, plasma is supplied into the chamber 11 by applying a source voltage from the source RF power supply 15 to the RF antenna 14 . At this time, a reactant gas, such as silane (SiH 4 ) and oxygen (O 2 ), is injected onto the substrate “w” on the susceptor 12 , and the bias RF power supply 17 is turned on. The reactant gas, such as silane (SiH 4 ) and oxygen (O 2 ), is changed into ions and active gases by colliding with electrons to depositing and etching a surface of the substrate “w”. The ions and electrons are accelerated by the bias RF power supply 17 . Generally, since a depositing rate is greater than an etching rate, the reactant gas is deposited on the substrate “w”. The active gases contribute to the depositing, while the ions and electrons contribute to the etching.
[0010] When a depositing process is performed without an etching process, there are voids in the gap. FIGS. 2A to 2C are cross-sectional views showing a void formed during a gap-filling process according to the related art. As shown in FIG. 2A , a plurality of gaps “T” are formed on the substrate “w”. As shown in FIG. 2B , A material is deposited on the substrate “w” and into the plurality of gaps “T”, and an inlet of the gap is much narrow than other portions of the gap. As a material is deposited, the inlet of the gap is choked before the inner space of the gap is perfectly filled with the material, thereby forming a void in the inner space of the gap. It may be referred to as an overhang phenomenon. Other portions of the gap except for the void are filled up by the material. To avoid the overhang phenomenon, the material deposited on the substrate “w” is etched by accelerated ions during deposition of the material.
[0011] However, since a width of metal line and a distance of devices, which are referred to as a critical dimension, decrease more and more, the above method, in which a material is deposited and etched at the same time to prevent the overhang phenomenon, has it's limits to prevent the void. It is because that a by-product from etching process is deposited again in the gap, not exhausted, as the critical dimension decreases. It makes the inlet of the gap narrowed. Since pressure around the inlet of the gap is higher than that of other portions of the gap due to ions and electrons diffused to the substrate, an etched material can not be exhausted.
[0012] As a result, when the critical dimension is less than 100 nm, there are some voids in the gap even if the material on the inlet of the gap is etched.
SUMMARY OF THE INVENTION
[0013] Accordingly, the present invention is directed to a method of gap-filling and an apparatus for the same that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
[0014] An object of the present invention is to provide a method of gap-filling being capable of filling a gap without voids and an apparatus for the same.
[0015] Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
[0016] To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a method of filling a gap on a substrate comprises disposing the substrate, on which the gap is formed, on a susceptor in a chamber; applying a source power to the chamber to generate plasmas into the chamber; supplying a process gas into the chamber; filling a thin film into a gap by applying a first bias power to the susceptor, an amplitude of the first bias power being periodically modulated; stopping supply of the process gas and cutting off the first bias power; and extinguish the plasmas in the chamber.
[0017] In another aspect, a method of filling a gap on a substrate disposed on a susceptor comprises forming plasmas over the substrate; supplying a process gas over the substrate; applying a first power to the susceptor to deposit the process gas onto the substrate and fill a thin film into the gap, the first power being modulated to have different amplitudes; stopping supply of the process gas and cutting off the first power; and extinguishing the plasmas.
[0018] In another aspect, a method of filling a gap on a substrate, the method including supplying a source power into a chamber to generate plasmas, injecting a process gas into the chamber, and supplying a bias power to a susceptor, on which the substrate is disposed, in the chamber to deposit the process gas onto the substrate and fill the gap comprises executing a first step of increasing acceleration of ion of the process gas diffused onto the substrate; and executing a second step of decreasing acceleration of ion of the process gas diffused onto the substrate, wherein the first step and the second step are periodically repeated.
[0019] In another aspect, an apparatus for filling a gap on a substrate comprises a chamber having an inner space; a susceptor, on which the substrate is disposed, in the inner space of the chamber; a gas injector supplying a processing gas into the chamber; a plasma generating unit disposed at an upper side of the chamber; a source RF power supply applying a source power to the plasma generating unit; a bias RF power supply supplying a bias power to the susceptor; and an amplitude modulation unit between the bias RF power supply and the susceptor, wherein the bias power is modulated by the amplitude modulating unit to have different amplitudes.
[0020] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings:
[0022] FIG. 1 is a schematic cross-sectional view showing a conventional high density plasma chemical vapor deposition (HDPCVD) apparatus.
[0023] FIGS. 2A to 2C are cross-sectional views showing a void formed during a gap-filling process according to the related art.
[0024] FIG. 3 is a schematic cross-sectional view showing a high density plasma chemical vapor deposition (HDPCVD) apparatus according to a first embodiment of the present invention.
[0025] FIG. 4 is a schematic view showing an amplitude modulation unit in the present invention.
[0026] FIG. 5 shows a waveform of an modulated power generating by an amplitude modulating unit.
[0027] FIGS. 6A and 6B show waveforms when a modulation index has a value of 0.5 and 1, respectively.
[0028] FIG. 7 is a flow chart showing a method of gap-filling.
[0029] FIG. 8 is a schematic cross-sectional view showing a high density plasma chemical vapor deposition (HDPCVD) apparatus according to a second embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Reference will now be made in detail to the preferred embodiments, examples of which are illustrated in the accompanying drawings.
[0031] FIG. 3 is a schematic cross-sectional view showing a high density plasma chemical vapor deposition (HDPCVD) apparatus according to a first embodiment of the present invention. As shown in FIG. 3 , a HDPCVD apparatus 100 includes a chamber 110 , a susceptor 120 , a gas injector 130 , a radiofrequency (RF) antenna 140 , a source RF power supply 150 , a bias RF power supply 170 , a direct current (DC) power supply 200 and an amplitude modulation unit 300 . The chamber 110 has an inner reactive space. An insulating plate 210 , which isolates an inner space of the chamber 110 from an outer space, is disposed on an upper wall of the chamber 110 . The susceptor 120 is disposed in the chamber 110 . A substrate “w” is loaded on the susceptor 120 . The gas injector 130 is disposed on opposite side walls of the chamber 110 and around the susceptor 120 . The gas is injected into the chamber 110 through the gas injector 130 . The RF antenna 140 is disposed over the chamber 110 and functions as a plasma injecting source. The RF antenna 140 is connected to the source RF power supply 150 . The bias RF power supply 170 , which controls an energy density of ion supplied onto the substrate “w”, is connected to the susceptor 120 . A source matching circuit 160 and a bias matching circuit 180 are respectively connected to the source RF power supply 150 and the bias RF power supply 170 to matches impedances. In addition, a direct current (DC) electrode 190 is formed in the susceptor 120 to be closet the substrate to the substrate 120 using a static electricity. The DC electrode 190 is formed of a metallic material such as tungsten (W). The DC electrode 190 is connected to a DC power supply 200 . The amplitude modulation unit 300 is connected to the bias matching circuit 180 and the bias RF power supply 170 . A power from the bias RF power supply 170 is modulated by the amplitude modulation unit 300 to have various amplitudes periodically. Accelerations of the ions diffused onto the substrate “w” are periodically changed depending on the amplitudes of the modulated powers. Namely, as a voltage of the bias RF power supply 170 increases, accelerations of the ions also increase. In other hands, when a voltage of the bias RF power supply 170 decreases, accelerations of the ions also decrease. The accelerations of the ions are proportional to the magnitude of the voltage of the bias RF power supply 170 . Moreover, an amount of ions diffused onto the substrate is proportional to the acceleration of the ions. Deposition and etching are more active when an amount of ions diffused onto the substrate “w” increases. Additionally, a by-product is much generated as an etching is more active. With a high acceleration of ion, ions diffused on an inner space of the gap increase and by-products on the inlet of the gap also increase. With a low acceleration of ion, both ions diffused on an inner space of the gap and by-products on the inlet decrease. Accordingly, when acceleration of ions decreases and ions diffused on the substrate “w” decrease, the by-products can be much exhausted to outer space of the gap. Since by-products are actively exhausted and are not deposited again on the substrate “w”, a deposition rate on the inlet portion of the gap decreases such that there are increased time to fill up the inner space of the gap. As a result, a void is not generated in the gap. Namely, the overhang phenomenon can be solved and there is no void in the gap with a low acceleration of ion.
[0032] FIG. 4 shows an amplitude modulation unit of an apparatus for gap-filling according to the present invention. As shown in FIG. 4 , the amplitude modulation unit 300 is connected to both a bias RF power supply 170 and the bias matching circuit 180 . The amplitude modulation unit 300 includes a local oscillator 310 , a power mixer 320 , a first amplifier 330 , a second amplifier 340 and a phase lock loop (PLL) 350 . The local oscillator 310 generates a power having a frequency different from that of the bias RF power supply 170 . The power from the local oscillator 310 has a frequency less than that of RF power supply 170 . The power mixer 320 receives and mixes powers from the bias RF power supply 170 and the local oscillator 310 . The first amplifier is connected to the power mixer 320 and receives the mixed power.
[0033] Assumes that a power function of the bias RF power supply 170 is “cos(ω c )t”, a power function of the local oscillator 310 is “1−cos(ω m )t”. In this case, a power function of the power mixer 320 is given by:
[0000] (1+cos(ω m )t)cos(ω c )t
[0034] Wherein “ω c ” and “ω m ” are angular frequencies of powers from the bias RF power supply 170 and the local oscillator 310 , respectively. And “m” is a modulation index.
[0035] The power of the power mixer 320 has a waveform shown in FIG. 5 . The waveform in FIG. 5 has an envelop with a maximum amplitude “A” and a minimum amplitude “B”. In this case, the modulation index “m” is given by:
[0000] m =( A−B )/( A+B )
[0036] Since the power function of the power mixer 320 is rewritten by:
[0000] (1+cos(ω m ) t )cos(ω c ) t =cos(ω c ) t +( m/ 2)cos(ω c +ω m ) t +( m/ 2)cos(ω c −ω m ) t
[0037] Accordingly, the power function of the power mixer 320 includes various frequencies, such as “ω c ”, “(ω c +ω m )” and “(ω c −ω m )”.
[0038] The bias RF power supply 170 has a frequency with a range between 100 KHz and 30 MHz. In more particular, the bias RF power supply 170 has a frequency of one of 2 MHz, 13.56 MHz and 27.12 MHz. The local oscillator 310 has a frequency with a range between 10 Hz and 2 MHz. The bias RF power supply 170 and the local oscillator 310 have frequencies with a relation by:
[0000] ω c ≧10ω m
[0039] On the other hand, a magnitude of the source RF power supply 150 is various depending on a size of the substrate “w”. However, a power of the source RF power supply 150 having a value less than 20 W/cm 2 is applied. If possible, the power of the source RF power supply 150 having a value greater than 20 W/cm 2 may be applied depending on requirement.
[0040] FIG. 5 is a graph plotting time versus voltage of power from a power mixer when the modulation index “m” is 0.5. An amplitude of power from the bias RF power supply 170 is modulated by the power mixer 320 to be various depending on time. The power from the power mixer 320 has three frequencies of “ω c ”, “(ω c +ω m )” and “(ω c −ω m )”, and has a maximum power at a range of the angular frequency “ω c ” of the bias RF power supply 170 .
[0041] Since the modulation index “m” is given by:
[0000] m =( A−B )/( A+B ),
[0042] a waveform of the power is various depending on a value of the modulation index “m”. For example, if the modulation index “m” has a value of 1, the minimum amplitude “B” of the envelope becomes zero such that the power is not transferred. And if the modulation index “m” has a value of 0.5, the maximum amplitude “A” of the envelope is three times as much as the minimum amplitude “B” of the envelope. (A=3B)
[0043] FIGS. 6A and 6B show waveforms when a modulation index has a value of 0.5 and 1, respectively. When the modulation index “m” has a relative low value, there are fluctuations of amplitude in the powers. However, there is no disconnection in the power. On the other hand, when the modulation index “m” has a relative high value, the minimum amplitude “B” (of FIG. 5 ) becomes a substantially zero such that the power is not transferred. Namely, when the modulation index “m” has a relative high value, there are much fluctuations of amplitude in the powers. Accordingly, in the present invention, the modulation index “m” has a value greater than 0.5 to have much fluctuations of the amplitude and much variance in acceleration of the ions.
[0044] Hereinafter, a method of gap-filling in a high density plasma chemical vapor disposition (HDPCVD) device according to the present invention with reference to FIGS. 3 and 7 . FIG. 7 is a flow chart showing a method of gap-filling.
[0045] First, in a first step “ST 110 ”, a substrate “w”, on which a plurality of gap is formed, is loaded on a susceptor 120 in a chamber 110 . Next, in a second step “ST 120 ”, an inert gas, such as argon (Ar), helium (He) and hydrogen (H2), is inject into the chamber 110 to stabilize the inner space of the chamber 110 . Next, in a third step “ST 130 ”, when the inner space of the chamber 110 is maintained to be constant, a source RF power supply 150 is turned on to generate plasma into the inner space of the chamber 110 . A current of the source RF power supply 150 has a value with a range between hundreds KHz and dozens MHz. The current of the source RF power supply 150 may have a value one of 13.56 MHz and 27.12 MHz. A power of the source RF power supply 150 is various depending on process conditions. The power of the source RF power supply 150 may have a value less than 20 W/cm2.
[0046] Next, in a fourth step “ST 140 ”, when plasma is stabilized, process gases are injected into the chamber 110 through the gas injector 130 , and the bias RF power supply 170 is turned on to apply a power having modulated amplitudes into the susceptor 120 . A kind of the process gases are various depending on what being deposited onto the substrate “w”. For example, when a silicon oxide layer is deposited onto the substrate “w”, a gas including silicon (Si), e.g., silane (SiH 4 ) gas, oxygen (O 2 ) gas and ozone (O 3 ) gas are used for the process gases. During the process gases being injected, the inert gas may be injected or not. Moreover, during the process gases being injected, pressure in the inner space of the chamber 110 may be maintained in pressure less than several mTorr. The inner space of the chamber 110 may have pressure less than 1 mTorr depending requirement. As mentioned above, to modulate amplitude of powers from the bias RF power supply 170 , a local oscillator 310 of the amplitude modulation unit 300 generates a power having a frequency with a range between 10 Hz and 2 MHz. In this case, an angular frequency “ω c ” of the bias RF power supply 170 and an angular frequency “ω m ” of the local oscillator 310 has a relation give by:
[0000] ω c ≧10ω m
[0047] In the fourth step “ST 140 ”, when a power from the bias RF power supply 170 is applied into the susceptor 120 , a rear side of the substrate “w” is cooled by using helium gas depending on process temperature.
[0048] Next, in a fifth step “ST 150 ”, a gap-filling process is performed to fill a thin film into the gap without voids. Namely, silane gas and oxygen gas are activated to be ions and activating gases and are deposited onto and etches surface of the substrate “w” at the same time. In the present invention, since a power of the bias RF power supply 170 is modulated by the amplitude modulation unit 300 and then applied into the susceptor 120 , accelerations of ions are fluctuated depending on amplitudes of the power. Accordingly, when the amplitude is high, amount of ions diffused onto the substrate “w” increases such that the depositing and etching are activated. On the other hand, when the amplitude is low, amount of ions diffused onto the substrate “w” decreases such that a depositing rate at a inlet portion of a gap decreases. It is because by-products are easily exhausted into an outer space of the gap, as mentioned above. Accordingly, the gap can be filled up by a material without a void.
[0049] Next, in sixth and seventh steps “ST 160 ” and “ST 170 ”, after finishing the gap-filling process, supply of the process gases is interrupted, the bias RF power supply 170 and the source RF power supply 150 are turned off. As a result, plasma disappears. Depending on requirement, the inert gas may be continuously supplied.
[0050] If the inert gas is continuously supplied, supply of the inert gas is interrupted in an eighth step “ST 180 ”. And then, in a ninth step “ST 190 ”, the substrate “w” is carried out.
[0051] On the other hand, in the fourth step “ST 140 ”, it is not required that the power having modulated amplitudes are applied during a whole process time. The power having modulated amplitudes may be applied during a initial process time, and a power without amplitude modulating may be applied during later process time. Namely, the depositing process includes a step of modulating the power and a step of non-modulating the power. When the step of modulating the power is changed into the step of non-modulating the power, a modulating index becomes smaller stepwise. The smaller the modulating index becomes, the smaller difference between a maximum amplitude of a modulated power from the power mixer and a minimum amplitude of the modulated power from the power mixer becomes.
[0052] On the other hand, the depositing process divided into three steps of an initial non-modulating step, a modulating step and a later non-modulating step.
[0053] In an initial stage of the depositing process, since the gap is filled up without voids and the aspect ratio becomes large, a power is not required to be modulated. When the gap is partially filled up, then, the modulating step is performed. And after the gap is filled up, the later non-modulating step is performed. Period of the initial non-modulating step is determined depending on a shape of the gap. When the initial non-modulating step is changed into the modulating step, a modulation index becomes larger stepwise. The larger the modulation index becomes, the larger difference between a maximum amplitude of a modulated power from the power mixer and a minimum amplitude of the modulated power from the power mixer becomes. And when the modulating step is changed into the later non-modulating step, a modulating index becomes smaller stepwise.
[0054] To obtain the above-mentioned process, a bias RF power supply 170 is connected to an amplitude modulation unit 300 via a switching unit 400 , as shown in FIG. 8 . FIG. 8 is a schematic cross-sectional view showing a high density plasma chemical vapor deposition (HDPCVD) apparatus according to a second embodiment of the present invention.
[0055] When the switching unit 400 is turned on, the bias RF power 170 is connected to the amplitude modulation unit 300 such that a power from the bias RF power 170 is modulated by the amplitude modulation unit 300 . However, when the switching unit 400 is turned off, the bias RF power 170 is disconnected to the bias matching circuit 180 such that a power from the bias RF power 170 is not modulated by the amplitude modulation unit 300 . When the switching unit 400 is turned off, the bias RF power 170 is directly connected to a bias matching circuit 180 .
[0056] It will be apparent to those skilled in the art that various modifications and variations can be made in the apparatus having a high gas conductance without departing from the spirit or scope of the invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. | A method of filling a gap on a substrate comprises disposing the substrate, on which the gap is formed, on a susceptor in a chamber; applying a source power to the chamber to generate plasmas into the chamber; supplying a process gas into the chamber; filling a thin film into a gap by applying a first bias power to the susceptor, an amplitude of the first bias power being periodically modulated; stopping supply of the process gas and cutting off the first bias power; and extinguish the plasmas in the chamber. | 7 |
BACKGROUND
1. Technical Field
The disclosure generally relates to gas turbine engines.
2. Description of the Related Art
Gas turbine engines typically are designed to operate over a broad range of power settings in order to meet varying mission requirements. Unfortunately, various design tradeoffs typically are made in order to accommodate such a broad range of requirements. These tradeoffs oftentimes result in an engine that operates much of the time in a non-optimal manner.
SUMMARY
Gas turbine engine systems and related methods involving multiple gas turbine cores are provided. In this regard, an exemplary embodiment of a gas turbine engine comprises: an inlet; a blade assembly mounted to receive intake air via the inlet; and multiple gas turbine cores located downstream of the blade assembly, each of the multiple gas turbine cores being independently operative in a first state, in which rotational energy is provided to rotate the blade assembly, and a second state, in which rotational energy is not provided to rotate the blade assembly.
An exemplary embodiment of a gas turbine core assembly for mounting within a gas turbine engine that has a rotatable blade assembly comprises: a first gas turbine core comprising: a first compressor section; a first combustion section operative to receive compressed gas from the first compressor section; a first shaft; a first turbine section operative to impart rotational energy to the first compressor section via the first shaft; and a first drive segment coupled to the first shaft and operative to provide rotational energy from the first shaft to the blade assembly, the first drive segment being offset with respect to a centerline of the blade assembly.
An exemplary embodiment of a method for operating a gas turbine engine comprises: selectively operating at least one of multiple gas turbine cores of the gas turbine engine; and imparting rotational energy from the at least one of the multiple gas turbine cores to a blade assembly, the blade assembly being rotatable to provide a flow of gas to the multiple gas turbine cores.
Other systems, methods, features and/or advantages of this disclosure will be or may become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features and/or advantages be included within this description and be within the scope of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
FIG. 1 is a schematic diagram depicting an exemplary embodiment of a gas turbine engine.
FIG. 2 is a schematic cross-sectional view of the embodiment of FIG. 1 .
FIG. 3 is a flowchart depicting functionality of an embodiment of a gas turbine engine.
FIG. 4 is a schematic diagram depicting another exemplary embodiment of a gas turbine engine.
DETAILED DESCRIPTION
Gas turbine engine systems and related methods involving multiple gas turbine cores are provided, several representative embodiments of which will be described in detail. In this regard, FIG. 1 is a schematic diagram depicting an exemplary embodiment of a gas turbine engine.
As shown in FIG. 1 , gas turbine engine 100 incorporates an inlet 102 that provides intake air to a blade assembly 104 . In this embodiment, engine 100 is a turbofan, with the blade assembly being configured as a fan incorporating multiple variable pitch blades, e.g., blade 106 . However, in other embodiments, the blade assembly could be a set of blades of a compressor of a turbojet, for example. Thus, the concepts described herein should not be construed as being limited to turbofans.
Downstream of the blade assembly are located multiple gas turbine cores. Specifically, four such gas turbine cores are used in this embodiment although only cores 120 , 130 are shown for ease of illustration in FIG. 1 . Note that all four cores are depicted in FIG. 2 . In other embodiments, various other numbers and arrangements of gas turbine cores can be used.
Each of the gas turbine cores incorporates a casing, a compressor section, a combustion section, and a turbine section, with a shaft interconnecting the compressor section and the turbine section. Thus, gas turbine core 120 includes casing 121 , compressor section 122 , combustion section 124 , turbine section 126 and shaft 128 , whereas gas turbine core 130 includes casing 131 , compressor section 132 , combustion section 134 , turbine section 136 and shaft 138 . Each of the gas turbine cores is independently operable and can selectively provide rotational energy to the blade assembly. Notably, although depicted as single spool cores, various other configurations can be used in other embodiments.
In the embodiment of FIG. 1 , each gas turbine core is coupled to a corresponding clutch and gearbox that can provide rotational energy to the blade assembly via a main shaft 140 . Specifically, core 120 is able to apply torque to the blade assembly via a drive segment 129 , clutch 142 and gearbox 144 , and core 130 is able to apply torque to the blade assembly via drive segment 139 , clutch 146 and gearbox 148 .
Application of torque to the blade assembly can be accomplished in a variety of manners. For instance, a clutch can be configured to disengage a corresponding core from the blade assembly responsive to available torque of that core dropping below a threshold level. Thus, in such an embodiment, shutdown of the core can initiate the disengagement. In other embodiments, an operating core with fully available torque can be disengaged from the blade assembly by a clutch.
In some embodiments, a gas turbine core can be used to provide electricity. In this regard, engine 100 incorporates a generator 149 that is driven by a core; in this case, core 120 . Depending on the mode of operation, the generator can be driven whether or not core 120 is providing torque to the blade assembly. Thus, such a generator can be coupled to a core in various locations, such as between the core and the clutch or between the core and the gearbox, for example.
In operation, one or more of the cores can be shutdown based on the overall power requirements of the gas turbine engine 100 . For instance, if power requirements are high, all of the cores can be operating, whereas, if power requirements are low as few as one of the cores could be operating. This tends to improve thermodynamic efficiency of the engine as the operating core(s) can be operated within a high efficiency range of operating parameters.
Notably, efficiency of the engine can be further increased by altering one or more of various gas flow parameters. By way of example, in a high speed mode, in which all of the cores may be operating, fan pressure ratio of the engine can be increased, such as by reducing bypass flow and increasing blade angle of the variable pitch blades of the blade assembly. In contrast, in a reduced speed mode, in which less than all of the cores typically are operating, bypass ratio of the engine can be increased while decreasing the blade angle of the variable pitch blades of the blade assembly.
FIG. 2 is a schematic cross-sectional view of the embodiment of FIG. 1 . In particular, FIG. 2 depicts the four gas turbine cores ( 120 , 130 , 150 and 160 ) positioned annularly about the centerline of the gas turbine engine. In this embodiment, each gas turbine core shaft is oriented parallel and offset with respect to the main shaft. Additionally, each opposing pair of gas turbine cores exhibits axial symmetry about the centerline of the main shaft.
FIG. 3 is a flowchart depicting functionality of an embodiment of a gas turbine engine that includes multiple gas turbine cores. In this regard, the functionality (or method) may be construed as beginning at block 302 , in which at least one of multiple gas turbine cores of the gas turbine engine is selectively operated. In block 304 , rotational energy from the at least one of the multiple gas turbine cores is imparted to a blade assembly. Notably, the blade assembly is rotatable to provide a flow of gas to the multiple gas turbine cores.
Another embodiment of a gas turbine engine is depicted schematically in FIG. 4 . As shown in FIG. 4 , gas turbine engine 400 incorporates an inlet 402 that provides intake air to a blade assembly 404 .
Downstream of the blade assembly are located multiple gas turbine cores. Specifically, four such gas turbine cores are used in this embodiment although only cores 420 , 430 are shown for ease of illustration.
Each of the gas turbine cores incorporates a casing, a compressor section, a combustion section, and a turbine section, with a shaft interconnecting the compressor section and the turbine section. Thus, gas turbine core 420 includes casing 421 , compressor section 422 , combustion section 424 , turbine section 426 and shaft 428 , whereas gas turbine core 430 includes casing 431 , compressor section 432 , combustion section 434 , turbine section 436 and shaft 438 . Each of the gas turbine cores is independently operable and can selectively provide rotational energy to the blade assembly.
In the embodiment of FIG. 4 , each gas turbine core is coupled to a corresponding clutch and gearbox that can provide rotational energy to the blade assembly via a main shaft 440 . Specifically, core 420 is able to apply torque to the blade assembly via a drive segment 429 , clutch 442 and gearbox 444 , and core 430 is able to apply torque to the blade assembly via drive segment 439 , clutch 446 and gearbox 448 .
Notably, the blade assembly 404 of this embodiment is a compound fan incorporating a main (inner) fan 460 and a tip rotator 462 . In operation, main fan 460 provides a flow of air to the cores, as well as a flow of bypass air (via primary bypass inlets 464 ), during operation of the gas turbine engine. The tip rotor 462 selectively provides thrust based on the position of secondary bypass inlets 466 . Specifically, in the open position (depicted in the upper portion of FIG. 4 ), air is provided to the tip rotor for providing thrust, whereas, in the closed position (depicted in the lower portion of the figure), additional air is not provided to the tip rotor.
It should be emphasized that the above-described embodiments are merely possible examples of implementations set forth for a clear understanding of the principles of this disclosure. Many variations and modifications may be made to the above-described embodiments without departing substantially from the spirit and principles of the disclosure. By way of example, although the exemplary embodiments described herein involve the use of single stage fans, multiple stage fans could also be used. As another example, while multiple gearboxes also have been described (i.e., each turbine core uses a corresponding gearbox), other embodiments multiple turbine cores could share one or more gearboxes. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the accompanying claims. | Gas turbine engine systems and related methods involving multiple gas turbine cores are provided. In this regard, a representative gas turbine engine includes: an inlet; a blade assembly mounted to receive intake air via the inlet; and multiple gas turbine cores located downstream of the blade assembly, each of the multiple gas turbine cores being independently operative in a first state, in which rotational energy is provided to rotate the blade assembly, and a second state, in which rotational energy is not provided to rotate the blade assembly. | 5 |
CLAIM TO PRIORITY
This application is a continuation of U.S. application Ser. No. 10/461,822, filed on Jun. 13, 2003, now U.S. Pat. No. 7,241,953, which claims priority under 35 USC 119(e) from Provisional application No. 60/462,983, filed Apr. 15, 2003.
FIELD OF INVENTION
This invention relates to high performance multi-media communications cables utilizing paired or unpaired electrical conductors with or without optical fibers, and/or coaxial conductors and/or twisted pair conductors. The metal conductors may be shielded or unshielded or a combination of both depending on the utility requirements. More particularly, it relates to support-separators or spacers for cables, which may perform as self-contained cables, having a central core defining singular or plural individual pair channels with allowance for hollow tubes that may initially be void of, or filled with one or more fiber optic, coaxial, or twisted pair conductors. The tubes or fiber ducts may be initially empty, but may be used in a future installation for one or more fibers or conductors. Additionally, a pull tape may be inserted in the tubes that may be used to pull one or more fibers or other conductor(s) into an existing cable. The communications cables have interior core support-separators that define a clearance channel through which conductors or optical fibers may be disposed.
BACKGROUND OF THE INVENTION
Many communication systems utilize high performance cables normally having four pairs or more that typically consist of two twisted pairs transmitting data and two receiving data as well as the possibility of four or more pairs multiplexing in both directions. A twisted pair is a pair of conductors twisted about each other. A transmitting twisted pair and a receiving twisted pair often form a subgroup in a cable having four twisted pairs. High-speed data communications media in current usage include pairs of wire twisted together to form a balanced transmission line. Optical fiber cables may include such twisted pairs or replace them altogether with optical transmission media (fiber optics).
When twisted pairs are closely placed, such as in a communications cable, electrical energy may be transferred from one pair of a cable to another. Energy transferred between conductor pairs is undesirable and referred to as crosstalk. The Telecommunications Industry Association and Electronics Industry Association have defined standards for crosstalk, including TIA/EIA-568B for Category 5e and proposed ISO/EC 11801 Category 6. The International Electrotechnical Commission has also defined standards for data communication cable crosstalk, including ISO/EEC 11801. One high-performance standard for 100 MHz cable is ISO/IEC 11801, Category 5. Additionally, more stringent standards are being implemented for higher frequency cables including Category 6 and Category 7, which includes frequencies of 200 and 600 MHz, respectively. Transmission rates of as much as 10 G-base-T employing 10 Gigabit Ethernet over copper at frequencies of 650 MHz or higher are now either anticipated or included as new industry standards emerge. Industry standards cable specifications and known commercially available products are listed in Table 1.
TABLE 1
INDUSTRY STANDARD CABLE SPECIFICATIONS
ANIXTER
ANIXTER
TIA CAT 6
XP6
XP7
ALL DATA AT
DRAFT 10
R3.00XP
R3.00XP
100 MHz
TIA CAT 5e
Nov. 15, 2001
November 2000
November 2000
MAX TEST
100
MHz
250
MHz
250
MHz
350
MHz
FREQUENCY
ATTENTUATION
22.0
db
19.8
db
21.7
db
19.7
db
POWER SUM
32.3
db
42.3
db
34.3
db
44.3
db
NEXT
ACR
13.3
db
24.5
db
POWER SUM
10.3
db
22.5
db
12.6
db
23.6
db
ACR
POWER SUM
20.8
db
24.8
db
23.8
db
25.8
db
ELFEXT
RETURN LOSS
20.1
db
20.1
db
21.5
db
22.5
db
In conventional cable, each twisted pair of conductors for a cable has a specified distance between twists along the longitudinal direction. That distance is referred to as the pair lay. When adjacent twisted pairs have the same pair lay and/or twist direction, they tend to lie within a cable more closely spaced than when they have different pair lays and/or twist direction. Such close spacing increases the amount of undesirable cross-talk that occurs. Therefore, in many conventional cables, each twisted pair within the cable has a unique pair lay in order to increase the spacing between pairs and thereby to reduce the cross-talk between twisted pairs of a cable. Twist direction may also be varied. Along with varying pair lays and twist directions, individual solid metal or woven metal air shields, i.e. aluminum laminated to polyethylene terephthalate (PET) shields and/or woven metal such as braid shields, can be used to electro-magnetically isolate pairs from each other or isolate the pairs from the cable jacket and the surrounding environment.
Shielded cable, although exhibiting better cross-talk isolation, is more difficult, time consuming and costly to manufacture, install, and terminate. Individually shielded pairs must generally be terminated using special tools, devices and techniques adapted for the job, also increasing cost and difficulty.
One popular cable type meeting the above specifications is Unshielded Twisted Pair (UTP) cable. Because it does not include shielded pairs, UTP is preferred by installers and others associated with wiring building premises, as it is easily installed and terminated. However, UTP fails to achieve superior cross-talk isolation such as required by the evolving higher frequency standards for data and other state of the art transmission cable systems, even when varying pair lays are used.
Some cables have used supports in connection with twisted pairs. These cables, however, suggest using a standard “X”, or “+” shaped support, hereinafter both referred to as the “X” support. Protrusions may extend from the standard “X” support. The protrusions of these prior inventions have exhibited substantially parallel sides.
The document, U.S. Pat. No. 3,819,443, to Sun Chemical Corporation, hereby incorporated by reference, describes a shielding member comprising laminated strips of metal and plastics material that are cut, bent, and assembled together to define radial branches on said member. It also describes a cable including a set of conductors arranged in pairs, said shielding member and an insulative outer sheath around the set of conductors. In this cable the shielding member with the radial branches compartmentalizes the interior of the cable. The various pairs of the cable are therefore separated from each other, but each is only partially shielded, which is not so effective as shielding around each pair and is not always satisfactory.
The solution to the problem of twisted pairs lying too closely together within a cable is embodied in three U.S. Pat. No. 6,150,612 to Prestolite, U.S. Pat. No. 5,952,615 to Filotex, and U.S. Pat. No. 5,969,295 to CommScope incorporated by reference herein, as well as an earlier similar design of a cable manufactured by Belden Wire & Cable Company as product number 1711A. The prongs or splines in the Belden cable provide superior crush resistance to the protrusions of the standard “X” support. The superior crush resistance better preserves the geometry of the pairs relatives to each other and of the pairs relative to the other parts of the cables such as the shield. In addition, the prongs or splines in this invention preferably have a pointed or slightly rounded apex top which easily accommodates an overall shield. These cables include four or more twisted pair media radially disposed about a “+”-shaped core. Each twisted pair nests between two fins of the “+”-shaped core, being separated from adjacent twisted pairs by the core. This helps reduce and stabilize crosstalk between the twisted pair media. U.S. Pat. No. 5,789,711 to Belden describes a “star” separator that accomplishes much of what has been described above and is also herein incorporated by reference.
However, these core types can add substantial cost to the cable, as well as excess material mass which forms a potential fire hazard, as explained below, while achieving a crosstalk reduction of typically 3 dB or more. This crosstalk value is based on a cable comprised of a fluorinated ethylene-propylene (FEP) conductors with low smoke PVC jackets as well as cables constructed of FEP, PVDF, and ECTFE jackets with FEP insulated conductors. for meeting NFPA 262 plenum applications for fire retardant and smoke suppression requirements. For riser applications (i.e. UL 1666, etc.), properly PVC jackets with polyolefin conductors are useful for meeting the U.S. standards, however, globally the need for halogen free jackets continues.
Cables where no separation between pairs exist will exhibit less desirable cross-talk values. When pairs are allowed to shift based on “free space” within the confines of the cable jacket, the fact that the pairs may “float” within a free space can reduce overall attenuation values due to the ability to use a larger conductor to maintain 100 ohm impedance. The movement occurs when the cable is put on new reels or on a reelex box during installation and stress on the conductor may cause electrical degradation. As the jacket proximity to the conductors is further removed, the electrical properties between conductors or conductor pairs may also improve. FIG. 8B is an example of the present invention which assists greatly in providing further separation of the cable jacket from individual or paired conductors. The trade-off with allowing the pairs to float is that the pair of conductors tend to separate slightly and randomly. This undesirable separation contributes to increased structural return loss (SRL) and more variation in impedance.
One method to overcome this undesirable trait is to twist the conductor pairs with a very tight lay. This method has been proven impractical because such tight lays are expensive and greatly limit the cable manufacturer's throughput and overall production yield. An improvement included by the present invention to structural return loss and improved attenuation is to provide a central circular ring region with various extending protrusions for pair separation.
The central ring portion can optionally include a hollow region to act as a hollow duct which is available for the future filling with optical fiber or coaxial cable or twisted pair conductors. Inside the central ring portion it is possible to have a second inner section that includes either a smooth or rifled surface as needed for blown finer applications. The fiber optic portions may be blown by gaseous means (normally air) or pulled into the hollow region with a pull tape. The fiber optics may be installed in the hollow duct in advance of the insertion of conductor pairs and an overall jacket. Also, future filling of the hollow ducts may occur with any of the communications media (fiber, coax, twisted pair, etc.). This ability to “future fill” gives the cable additional “dual” functionality and addresses the concern that installers share regarding the need to remove or add new wire and cable to existing plenum or non-plenum areas carrying older media.
Other improvements have been shown and filed in U.S. application US 2003/0037955/A1 filed at the United States Patent and Trademark Office on Aug. 25, 2001 and published Feb. 27, 2003 and subsequent PCT international publication number WO 03/021607 A1, filed May 1, 2002 and published 13 Mar. 2003.
Another improvement, and one that is included by the present invention, is to provide a circular ring region which is surrounded by rounded lobes in a symmetric diamond-like geometry that defines as many as four separate regions for pair separation and derivatives thereof. Again the central ring portion can optionally include a hollow region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber or for the aforementioned coaxial or twisted pair applications.
A third improvement included by the present invention is to provide a hollow four-petal or “daisy” shaped arrangement with a central core that may or may not be hollow, and derivatives thereof—again to allow for pair separation. Individual or paired conductors are placed within the hollow petals as required depending on electrical, mechanical, and flammability design requirements. If the central region is hollow, the possibility again exists for that region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber.
Still another improvement included by the present invention is to provide cross-like arrangement of varying geometric design and derivatives thereof. One such arrangement is a more conventional cross-like separator section with “rifled” sections extending outward into four quadrants away from the central region. This rifled cross is then encased within an outer insulated layer which is itself shaped in an identical cross except that the dimensions of this outer cross is larger than the rifled inner cross and functions as a “skin”. In this manner the separator uses less material than a conventional cross separator and thus reduces the BTU content within a jacketed (or even an unjacketed) cable. An optimal design that meets the stringent fire retardancy and smoke suppression requirements as well as the electrical needs, includes the use of an outer solid skin of either FEP or PVC sufficient to reduce flame and smoke over a foamed insulation material with a very low (nearer to 1.00 the better) dielectric constant. To pass recent CMP-50 requirements, lower fuel loads are very helpful. To reduce fuel loads, the addition of air and reduction of material are both useful methods for achieving the desired goals of improved flammability, smoke generation, and electrical properties of any cable construction using separators of the present invention. Dual extrusion is a commonly known method that can allow for a dual insulation design capable of providing such a product. Dual extrusion also allows for more sophisticated designs where lowering BTU content is important, as for example in the IEC C332-3B 1 and B 2 test protocols for European applications. Use of a pull tape within these constructions, the tape itself constructed from fire retardant, smoke reducing materials, is also part of the present invention and provides another avenue to meet the needs of upgrading existing cable installations when new internal communications media must be provided. Industry standards European Flammability Standards are listed in Table 2.
TABLE 2
European Flammability Specifications
Class
Test Methods
Classification Criteria (1)
Additional Classification
Ac
EN ISO 1716
PCS ≦2.0 MJ · kg −1 (2)
—
B1c
EN 50266-2-x (3)
FS ≦ 1.75 m; and
Smoke production (5) and
And
THR600s ≦ 7.5 MJ; and
Flaming droplets/particles (6);
Peak RHR ≦ 15 kW; and
And
FIGRA ≦ 120** W · s−1
Acidity/Corrosivity (7)
EN 50265-2-1
H ≦ 425 mm
B2c
EN 50266-2-x (3)
FS ≦ 2.00 m; and
Smoke production (5) and
And
THR600s ≦ 15 MJ; and
Flaming droplets/particles (6);
Peak RHR ≦ 50 kW; and
And
FIGRA ≦ 150** W · s−1
Acidity/Corrosivity (7)
EN 50265-2-1
H ≦ 425 mm
C1c
EN 50266-2-y (4)
FS ≦ 2.0 m; and
Smoke production (5) and
600s
THR600s ≦ 15 MJ; and
Flaming droplets/particles (6);
And
Peak RHR ≦ 50 kW; and
And
FIGRA ≦ 150** W · s−1
Acidity/Corrosivity (7)
EN 50265-2-1
H ≦ 425 mm
C2c
EN 50266-2-y (4)
FS ≦ 2.5 m; and
Smoke production (5) and
600s
THR600s ≦ 35 MJ; and
Flaming droplets/particles (6);
And
Peak RHR ≦ 100 kW; and
And
FIGRA ≦ 250** W · s−1
Acidity/Corrosivity (7)
EN 50265-2-1
H ≦ 425 mm
Dc
EN 50265-2-1
H ≦ 425 mm
Flaming droplets/particles (6); And
Acidity/Corrosivity (7)
Ec
No performance determined
**provisional figures
Yet another improvement included by the present invention is to provide variations on the cross-like arrangement by adding “zig-zag” with and without “sickle-like” endings regions instead of “rifled” sections extending outward into four quadrants away from the central region.
For all these configurations, a major purpose of the inventive design of these separators is to provide contributions to improved attenuation, power sum NEXT (near end cross talk), power sum ACR (attenuation cross-talk ratio) and ELFEXT (equal level far end cross-talk) by providing for better control of spacing of the pairs, adding more air-space, and allowing for “pair-twinning” at different lengths. Additional benefits include reduction of the overall material mass required for conventional spacers, which greatly contributes to flame and smoke reduction. The other major purpose is to allow for “future” or concurrent filling of any media such as optical, twisted pair, or coax conductors with sufficient spacing so that electrical and optical integrity is maintained.
In recent years, electro-optical equipment has begun to replace electronic equipment for certain applications, such as telecommunication and data communication networks. This trend should continue because the electro-optical equipment has inherent advantages over purely electronic equipment. These advantages include a broader bandwidth for signal transmission, greater storage capability for data, and inherent immunity to electromagnetic interference. Given these advantages of electro-optical equipment, fiber optic cables have become increasingly important because they transmit information and signals between the various pieces of electro-optical equipment.
The appearance of these cables resembles electrical cables, but fiber optic cables are smaller in size and lighter in weight. Fiber optic cables comprise optical fibers and other cable elements which are protected from the external environment by an external jacketing. These cables may be of a traditional design with the fibers surrounded by strength members and protective elements in the cable core or of a more non-traditional, loosely-bundled type with the fibers contained loosely within tubes or ducts in a cable core.
According to U.S. Pat. No. 4,997,256, optical fiber units may be suitable for installation by the force of a fluid flowing through a passage. The unit, in this case, includes at least one optical fiber and at least one interstitial cord. The fibers and cords are of the same diameter. They are bundled and surrounded by a first sheath that is formed of a material having a high Young's modulus. An outer sheath, of foamed polyethelene may surround the first sheath. More particularly, the invention described includes an improvement in the blowing and transmission properties of such an optical fiber unit.
The objects of the invention can be achieved by an optical fiber unit of a type that is to be installed by the drag force of a pressure fluid flowing through a pipe, containing at least one optical fiber and more than one interstitial cord which are bundled and surrounded by an inner and outer sheathing to provide a unitary assembly, which inner sheath is made of a resin that has a high Young's modulus and that exhibits small residual strain during the application of sheathing. The outer sheath is made of a foamed polyethylene.
Another object of this invention can be attained in an effective way if the interstitial cord used in the optical fiber unit has substantially the same outside diameter as the optical fiber. Further, the object of this invention can be attained in a more effective way if at least one of the interstitial cords has a sufficient strength to work as a rip cord that assists in ripping away the inner and outer sheaths when the optical fiber is withdrawn from the optical fiber unit during end preparations.
In the case of the present invention, the central “hollow” portion of the support-separator can act as the duct for accommodating the inventive entity described. The duct could be composed of polybutylene terephthalate, amorphous nylon or other suitable materials such as described in the U.S. Pat. No. 4,997,256 patent. Essentially all other aspects of the '256 patent which include installing optical fiber into predisposed duct can be incorporated into the present invention using the central hollow portions of the support separator as the predisposed duct.
U.S. Pat. No. 6,173,107 describes a method and apparatus for installing or advancing a lightweight and flexible transmission line along a tubular pathway comprising insertion of the free end of such a line into a previously installed pathway, and propelling the line along the pathway by fluid drag of a gaseous medium passed through the pathway in the desired direction of advance. The present invention may also incorporate this method and potentially the apparatus as described below for the same purpose utilizing the central core of the support-separators for ABF or pulling with a pull tape.
It should be appreciated that to generate sufficient fluid drag to propel the transmission line, the gaseous medium has to be passed through the pathway with a flow velocity much higher than the desired rate of advance.
The terms “lightweight and flexible” with respect to the transmission line are to be understood as meaning “sufficiently lightweight and flexible” for the transmission line to be propelled by the fluid drag. The flow velocity of the gaseous medium may be steady or may be suitably varied, for example either between a first velocity producing no, or insufficient, fluid drag to propel the fiber or wire member, and a second velocity producing sufficient fluid drag to propel the fiber or wire member, or between a first and second velocity both producing sufficient fluid drag for propelling the fiber or wire member. Conveniently the variations in velocity take the form of repeated abrupt changes between the first and second velocity. The aforementioned variations in flow velocity may include periods during which the flow is reversed with respect to the desired direction of advance of the transmission line.
It is to be understood that more than one transmission line may be propelled along the same tubular pathway.
A transmission line may, for example, comprise a single optical fiber or wire, protected by at least a primary coating but preferably contained within an outer envelope. Alternatively, a fiber or wire member may comprise a plurality of optical fibers or wires contained within a common envelope. The envelope may loosely or tightly surround the fiber (wire), or fibers (wires).
The method may be used for insertion of an optical fiber or wire member into, or its withdrawal from, the pathway.
The gaseous medium is chosen to be compatible with the environment in which the invention is performed, and in ordinary environments will be a non-hazardous gas or gas mixture. With the proviso about compatibility with the environment, the gaseous medium is preferably air or nitrogen.
The tubular pathways and/or the fiber or wire members are conveniently but not necessarily of circular cross-section, and the fiber or wire member is always smaller than the pathway. In practice, when installing an optical fiber member, the pathway internal diameter will generally be greater, and frequently much greater than 1 mm, and the external diameter of the fiber member greater than 0.5 microns.
A preferred range of diameters for the pathway is 1 to 10 mm, conveniently between 3 and 7 mm, and a preferred range of diameters for the fiber members is 1 to 4 mm, although much larger diameters may be used provided the fiber member is sufficiently lightweight and flexible. The diameter of the fiber member or members is preferably chosen to be greater than one tenth, and conveniently to be about one half of the pathway diameter or greater (and appropriately less, of course, if more than one fiber member is to be propelled through the same pathway). For single mode fiber the fiber and cladding diameter range is normally from 7-250 microns and for multimode fiber the range is normally between 250 and 900 microns.
Insertion of a fiber (or wire) member by means of the fluid drag of a gas passing over the fiber member has several advantages over methods involving pulling an optical fiber (wire) cable with a pull cord.
Firstly, the extra step of providing a pull cord or flat pull tape with a Kellum-like grip is eliminated.
Secondly, using the fluid drag of a gaseous medium produces a distributed pulling force on the fiber (wire) member. This is particularly advantageous if the installation route contains one or more bends. If, as would be the case with a pulling cord, the pulling force were concentrated at the leading end of the fiber member, any deviation of the pathway from a straight line would greatly increase friction between the fiber member and the internal walls of the pathway, and only a few bends would be sufficient to cause locking of the fiber. The distributed pulling force produced by the fluid drag, on the other hand, enables bends to be negotiated fairly easily, and the number of bends in a given installation is no longer of much significance.
Thirdly, the fluid drag substantially reduces overall pulling stress on the fiber (or wire) member and so permits the fiber (or wire) member to be of relatively simple and cheap construction.
Furthermore, because the fiber member is not subjected to any substantial pulling stress during installation, little allowance, if any, needs to be made for subsequent relaxation.
According to a further aspect of the invention described in U.S. Pat. No. 6,173,107, a method of installing a transmission line comprises installing a conduit having one or more ductlets providing tubular pathways. The ductlets described below, for the present invention, may be the central hollow regions of any shape associated with the support-separators described.
The communications route may be initially designed and upgraded according to a customer's needs or desires. For example, after installation of the communications cable with support-separator, wire members containing one or more lightweight and flexible wires initially may be propelled through a pathway using fluid drag. Thereafter, the route may be upgraded by installing further wire members and/or inserting, by the aforesaid method using fluid drag, one or more fiber members into the associated ductlets as required. It would also be possible to remove fiber from existing ducts and reinstall newer fiber or new conductors as needed. In some cases, it may be possible to remove the duct itself and re-install (or not depending on the need).
Installing optical fiber and/or wire transmission lines by this method has several advantages over conventional techniques.
First, since the conduit is installed without containing any optical fibers, conventional rope pulling and similar techniques may be freely employed for installing the conduit.
Second, the capacity can readily be adapted to requirements. Thus, while initially only one or two fiber or wire members may be sufficient to carry the traffic, multiple cables may contain a much larger number of ductlets than are required at the time of installation, and further fiber or other members may be inserted later on as and when needed. The support-separator of the present invention is cheap compared to the cost of the fibers, and spare ductlets to accommodate further fibers and/or wires as and when extra capacity is required can thus be readily incorporated without adding more than a small fraction to overall costs.
The method of the U.S. Pat. No. 6,173,107 invention also permits the installation of improved later generations of transmission lines. It is possible, for example, to install at first one or more fiber members incorporating multimode fibers, and at a later date add, or replace the installed multimode fiber members with fiber members incorporating monomode fibers. Installed fiber members may conveniently be withdrawn from the ductlet, and replacement fiber members be inserted by using the aforesaid method of propelling by fluid drag of a gaseous medium.
Alternatively, the support-separators may comprise a plurality of individual tubes enveloped by a common outer sheath.
It will be appreciated that the present invention largely avoids the risk, inherent in handling optical fiber cables with a large number of fibers, of accidentally damaging before or during installation in a single event a large number of expensive optical fibers.
The present invention also enables the installation of continuous optical fibers over several installation lengths without joints.
Furthermore, individual fiber members routed through the conduit can be routed, without requiring fiber joints, into different branches of the conduits at various junction points.
Finally, a unique construction of the blown fiber duct or ductlets is described in WO patent application 01/34366 entitled: “Flexible plastic Tubing Construction Having a Sight Glass Window.”
Accordingly, the tubing construction of the invention herein involved is particularly adapted for use in ABF applications and other cable or wire installations wherein the ability to view the cables or wires within the tubing is desired for installation, servicing, or administration. It is possible that the present invention could incorporate the principals of the 01/34366 invention as well.
In another illustrative embodiment of the 01/34366 invention, the tubing (or in the case of the present invention—the lining of the inner central hollow core extending along the length of the support-separator) includes a third sidewall segment formed integrally with the first and second segments as having inner surface, which defines a portion of tubing innermost surface. Such inner surface may be profiled as defining a series of radially-disposed longitudinal splines, ribs, or other projections. With respect to ABF installation, such projections have been observed to reduce surface area contact between the cable and tubing sidewall, which results in corresponding decreased friction as the cable is blown through the tubing. Such projections also develop a lower velocity boundary layer in the gas flow near the surface which has the tendency to direct the fiber into the higher velocity flow towards the center of the tubing. The end result is less drag on the tubing which facilitates long runs and direction changes such as around bends.
Advantages of the 01/34366 invention include a flexible plastic tubing construction which is provided as having a sight-glass capability without affecting the gross fire resistance, electrical conductivity, or other specified chemical without affecting the gross fire resistance, electrical conductivity, or other specified chemical or physical properties of the tubing. Additional advantages include a tubing construction which is economical to manufacture in long, continuous lengths, and which further is particularly adapted for use in ABF installations. These and other advantages will be readily apparent to those skilled in the art based upon the disclosure contained herein.
As described above, an additional purpose of the present invention is to form and allow the central hollow region of the support separator spacers of the communications cables to act as a duct for ABF in the event this is desirable for installation purposes. The materials used to construct the support separators can be solid, semi-solid, foamed, foamed with a solid skin, or hollow. The lining of the central hollow region can be composed of polybutylene terephthalate (PBT) or other known materials capable of providing a sufficient combination of lubricity and friction to ensure proper accommodation of blown fiber “post” installation. There may be a separate inner lining within the central ring portion and it is always possible that the inner lining can be used such as shown in FIG. 1B .
Many precautions are taken to resist the spread of flame and the generation of and spread of smoke throughout a building in case of an outbreak of fire. Clearly, cables must be designed to protect against loss of life and also minimize the costs of a fire due to the destruction of electrical and other equipment. Therefore, wires and cables for building installations are required to comply with the various flammability requirements of the National Electrical Code (NEC) in the U.S. as well as International Electrotechnical Commission (EIC) and/or the Canadian Electrical Code (CEC).
Cables intended for installation in the air handling spaces (i.e. plenums, ducts, etc.) of buildings are specifically required by NEC/CEC/IEC to pass the flame test specified by Underwriters Laboratories Inc. (UL), UL-910, or its Canadian Standards Association (CSA) equivalent, the FF6. The UL-910 and the FT6 represent the top of the fire rating hierarchy established by the NEC and CEC respectively. Also important are the UL 1666 Riser test and the IEC 60332-3C and D flammability criteria. Cables possessing these ratings, generically known as “plenum” or “plenum rated” or “riser” or “riser rated”, may be substituted for cables having a lower rating (i.e. CMR, CM, CMX, FT4, FTI or their equivalents), while lower rated cables may not be used where plenum or riser rated cables are required. Future ratings include the CMP-50 standard which is considered to the European requirement of the future.
Cables conforming to NEC/CEC/IEC requirements are characterized as possessing superior resistance to ignitability, greater resistance to contribute to flame spread and generate lower levels of smoke during fires than cables having lower fire ratings. Often these properties can be anticipated by the use of measuring a Limiting Oxygen Index (LOI) for specific materials used to construct the cable. Conventional designs of data grade telecommunication cable for installations in plenum chambers have a low smoke generating jacket material, e.g. of a specially filled PVC formulation or a fluoropolymer material, surrounding a core of twisted conductor pairs, each conductor individually insulated with a fluorinated insulation layer. Cable produced as described above satisfies recognized plenum test requirements such as the “peak smoke” and “average smoke” requirements of the Underwriters Laboratories, Inc., UL910 Steiner tunnel test and/or Canadian Standards Association CSA-FT6 (Plenum Flame Test) while also achieving desired electrical performance in accordance with EIA/TIA-568A for high frequency signal transmission.
While the above described conventional cable, including the Belden 1711A cable design, due in part to their use of fluorinated polymers, meets all of the above design criteria, the use of fluorinated polymers is extremely expensive and may account for up to 60% of the cost of a cable designed for plenum usage. A solid core of these communications cables contributes a large volume of fuel to a potential cable fire. Forming the core of a fire resistant material, such as with FEP (fluorinated ethylene-propylene), is very costly due to the volume of material used in the core, but it should help reduce flame spread over the 20 minute test period. Reducing the mass of material by redesigning the core and separators within the core is another method of reducing fuel and thereby reducing smoke generation and flame spread. For the commercial market in Europe, low smoke fire retardant polyolefin materials have been developed that will pass the EN (European Norm) 502666-Z-X Class B relative to flame spread, total heat release, related heat release, and fire growth rate. Prior to this inventive development, standard cable constructions requiring the use of the aforementioned expensive fluorinated polymers, such as FEP, would be needed to pass this rigorous test. Using low smoke fire retardant polyolefins or foamed low smoke semi-rigid PVC for specially designed separators used in cables that meet the more stringent electrical requirements for Categories 6 and 7 and also pass the new norm for flammability and smoke generation is also a further subject of the present invention.
Solid flame retardant/smoke suppressed polyolefins may also be used in connection with fluorinated polymers. Commercially available solid flame retardant/smoke suppressed polyolefin compounds all possess dielectric properties inferior to that of FEP and similar fluorinated polymers. In addition, they also exhibit inferior resistance to burning and generally produce more smoke than FEP under burning conditions. A combination of the two different polymer types can reduce costs while minimally sacrificing physio-chemical properties. An additional method that has been used to improve both electrical and flammability properties includes the irradiation of certain polymers that lend themselves to crosslinking. Certain polyolefins are currently in development that have proven capable of replacing fluoropolymers for passing these same stringent smoke and flammability tests for cable separators, also known as “cross-webs”. Dual insulation designs as previously mentioned are also useful in this application. Additional advantages with the polyolefins are reduction in cost and toxicity effects as measured during and after combustion.
Current separator designs must also meet the UL 910 flame and smoke criteria using both fluorinated and non-fluorinated jackets as well as fluorinated and non-fluorinated insulation materials for the conductors of these cable constructions. In Europe, the trend continues to be use of halogen free insulation for all components, which also must meet stringent flammability regulations. The test in Europe which the present inventive separators and subsequent cables should also pass is known as “B-1”.
A high performance communications data cable utilizing twisted pair technology must meet exacting specification with regard to data speed, electrical, as well as flammability and smoke characteristics. The electrical characteristics include specifically the ability to control impedance, near-end cross-talk (NEXT), ACR (attenuation cross-talk ratio) and shield transfer impedance. A method used for twisted pair data cables that has been tried to meet the electrical characteristics, such as controlled NEXT, is by utilizing individually shielded twisted pairs (ISTP). These shields insulate each pair from NEXT. Data cables have also used very complex lay techniques to cancel E and B (electric and magnetic fields) to control NEXT. In addition, previously manufactured data cables have been designed to meet ACR requirements by utilizing very low dielectric constant insulation materials. Use of the above techniques to control electrical characteristics have inherent problems that have lead to various cable methods and designs to overcome these problems.
Recently, the development of “high-end” electrical properties for Category 6 and 7 cables has increased the need to determine and include power sum NEXT (near end crosstalk) and power sum ELFEXT (equal level far end crosstalk) considerations along with attenuation, impedance, and ACR values. These developments have necessitated the development of more highly evolved separators that can provide offsetting of the electrical conductor pairs so that the lessor performing electrical pairs can be further separated from other pairs within the overall cable construction.
Recent and proposed cable standards are increasing cable maximum frequencies from 100-200 MHz to 250-700 MHz. In the case of the present invention, the intention is to meet design criteria so that the conductors are capable of carrying signals at or above 10 GHz. The maximum upper frequency of a cable is that frequency at which the ACR (attenuation/cross-talk ratio) is essentially equal to 1. Since attenuation increases with frequency and cross-talk decreases with frequency, the cable designer must be innovative in designing a cable with sufficiently high cross-talk. This is especially true since many conventional design concepts, fillers, and spacers may not provide sufficient cross-talk at the higher frequencies.
Individual shielding is costly and complex to process. Individual shielding is highly susceptible to geometric instability during processing and use. In addition, the ground plane of individual shields, 360° in ISTP's—individually shielded twisted pairs—is also an expensive process. Lay techniques and the associated multi-shaped anvils of the present invention to achieve such lay geometries are also complex, costly and susceptible to instability during processing and use. Another problem with many data cables is their susceptibility to deformation during manufacture and use. Deformation of the cable geometry, such as the shield, also potentially severely reduces the electrical and optical consistency. The “cross-web” designs currently in use provide primarily an unshielded pair, but it increase EMI/RFI shielding effectiveness, the present invention includes the use of “shielded cross-webs”.
Optical fiber cables exhibits a separate set of needs that include weight reduction (of the overall cable), optical functionality without change in optical properties and mechanical integrity to prevent damage to glass fibers. For multi-media cable, i.e. cable that contains both metal conductors and optical fibers, the set of criteria is often incompatible. The use of the present invention, however, renders these often divergent set of criteria compatible. Specifically, optical fibers must have sufficient volume in which the buffering and jacketing plenum materials (FEP and the like) covering the inner glass fibers can expand and contract over a broad temperature range without restriction, for example −40 C. to 80 C. experienced during shipping. It has been shown by that cyclical compression and expansion directly contacting the buffered glass fiber causes excess attenuation light loss (as measured in dB) in the glass fiber. The design of the present invention allows for designation and placement of optical fibers in clearance channels provided by the support-separator. It would also be possible to place both glass fiber and metal conductors in the same designated clearance channel if such a design is required. In either case the forced spacing and separation from the cable jacket (or absence of a cable jacket) would eliminate the undesirable set of cyclical forces that cause excess attenuation light loss. In addition, fragile optical fibers are susceptible to mechanical damage without crush resistant members (in addition to conventional jacketing). The present invention also addresses this problem and allows for “air” blown fiber ducts for installation of fiber optics at a later time in existing installations. Here “air” refers to any gas that can be used to convey fiber down the duct (or “tube”—an empty or hollow section of the separator).
The need to continue improving cable and cable separator designs by reducing costs and improving mechanical and electrical properties as well as flammability continues to exist.
SUMMARY OF THE INVENTION
This invention provides a lower cost communications cable and/or a support separator for the communications cable exhibiting improved electrical, flammability, and optionally, optical properties. The cable or separator or cable with one or more separators have interior support(s) extending along the longitudinal length of the communications cable. The interior support has a central region extending along the longitudinal length of the interior support. In a preferred configuration, the cable includes a geometrically symmetrical core with a central circular ring region with various extending protrusions for pair separation and derivatives thereof. The central ring portion can optionally include a hollow region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber.
In the present invention it is also desirable to provide a circular ring region which is surrounded by rounded lobes in a symmetric diamond-like geometry and derivatives thereof that define as many as four separate regions for pairs that are properly separated in the final (often jacketed) cable design. Again the central ring portion can optionally include a hollow region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber.
A third embodiment of the present invention provides a hollow four-petal or “daisy” shaped arrangement with a central core that may or may not be hollow and derivatives thereof—again to allow for pair separation. Individual or paired conductors are placed within the hollow petals as required depending on electrical, mechanical, and flammability design requirements. If the central region is hollow, the possibility again exists for that region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber.
Still another embodiment of the present invention is to provide a cross-like arrangement of varying geometric designs and derivatives thereof. One such arrangement is a more conventional cross-like separator section with “rifled” sections extending outward into four quadrants away from the central region. This rifled cross is then encased or covered within an outer insulated layer which is itself shaped in an identical cross except that the dimensions of this outer cross is larger than the rifled inner cross and functions as a “skin”. In this manner the separator uses less material than a conventional cross separator and thus reduces the BTU content within a jacketed (or even an unjacketed) cable.
Yet another embodiment includes providing variations on the cross-like arrangement by adding “zig-zag” with and without “sickle-like” endings regions instead of the “rifled” sections extending outward into four quadrants away from the central region as described above.
The core support-separator is optionally foamed, semi-solid, solid skin over foam or hollow and has an optional hollow center. The rifled cross separator profiles with ladder-like “step-sections” are similar to standard “X” supports with the major difference that they include step sections that lie under a solid insulation along the radially extending portions of the support. This provides for a hollow-cross-like support separator that includes less overall material weight, thereby reducing potential BTU content and thus reduces the risk of flame spread in a fire scenario.
These various shaped sections of the core support-separator may be helixed as the core extends along the length of the communications cable. Each of the adjacent shaped sections defines a clearance or clearance channel which extends along the longitudinal length of the multi-anvil shaped core support-separator. The clearance provides a channel for each of the conductors/optical fibers or conductor pairs used within the cable. The clearance channels formed by the various shaped core support-separators extend along the same length of the central portion. The channels are either semi-circular, fully circular, or stepped in a circular-like manner shaped cross-section with completely closed surfaces in the radial direction toward the center portion of the core and optionally opened or closed surfaces at the outer radial portion of the same core. Adjacent channels are separated from each other to provide a chamber for at least a pair of conductors or an optical fiber or optical fibers.
Additionally, to provide a duct for ABF, the central regions of the separators can be hollow to allow for “post installation” of optical fibers.
The various shaped core support-separators of this invention provides a superior crush resistance to the protrusions of the standard “X” or other similar supports. A superior crush resistance is obtained by the circular and arch-like design for separators that provide clearance channels for additional support to the outer section of the cable. The various shaped cores better preserves the geometry of the pairs relative to each other and of the pairs relative to the other parts of the cables, such as the possible use of a shield or optical fibers. The circular shape provides an exterior surface that essentially establishes the desired roundness for cable manufacturers. The exterior roundness ensures ease of die development and eventual extrusion. The rounded surface of the core also allows for easy accommodation of an overall external shield.
The four-pedal or daisy shape separator sections provide similar crush resistance to the standard “X” supports with the additional feature that the center portion of the separator may have hollow sections for the use blown finer ducts. Additionally, these supports carry the conductors inside hollow sections offering an additional level of mechanical integrity.
Additionally, the daisy shaped separator may include the use of single or double sided PET—Aluminum film which is as much as 0.004″ (4 mil) in thickness to further provide shielding effectiveness and provide ingress of attenuated signals. It is also possible, in this geometry to include twisted pair conductors between the individual hollow petals such that separation between twisted pair conductors can be accomplished in this manner.
The conductors can be set apart in each of these unique geometries so that individual or sets of pairs can be spaced closer or farther apart from one another, allowing for better power sum values of equal level far end and near end crosstalk. This “offsetting” between conductor pairs in a logical, methodological pattern to optimize electrical properties is an additional benefit associated with the cross-shaped separators that include “zig-zag” and sickle-like sections.
According to one embodiment, the cable includes a plurality of transmission media with metal and/or optical conductors that are individually disposed; and an optional outer jacket maintaining the plurality of data transmission media in proper position with respect to the core. The core is comprised of a support-separator having various shaped profiles that define a clearance to maintain spacing between transmission media or transmission media pairs in the finished cable. The core may be formed of a conductive or insulative material to further reduce cross-talk, impedance and attenuation.
Accordingly, the present invention provides for a communications cable, with a specifically shaped support-separators, that meet the exacting specifications of high performance data cables and/or fiber optics or the possibility of including both transmission media in one cable, has a superior resistance to deformation during manufacturing and use, allows for control of near-end cross-talk, controls electrical instability due to shielding, is capable of 200 and 600 MHz (Categories 6 and 7) transmission and possibly up to or greater than 1 GHz, with a positive attenuation to cross-talk ratio (ACR ratio) of typically 3 to 10 dB.
Moreover, the present invention provides a separator so that the jacket material (which normally has inferior electrical properties as compared with the conductor material) is actually pushed away from the electrical conductor, thus acting to again improve electrical performance (ACR, etc.) over the life of the use of the cable. These separators, by simple geometric considerations are also superior to the “X” type separator in that they also increase the physical distance between the conductor pairs within the same cable configuration, as shown in FIGS. 7A and B.
Additionally, it has been known that the conductor pair may actually have physical or chemical bonds that allow for the pair to remain intimately bound along the length of the cavity in which they lie. The present invention describes a means by which the conductor pairs are adhered to or forced along the cavity walls by the use of grooves that may exist within the inner diameters of the circular ring and daisy-like geometries. This again increases the distance, thereby increasing the volume of air or other dielectrically superior medium between conductors in separate cavities. As discussed above, spacing between pairs, spacing away from jackets, and balanced spacing all have an effect on final electrical cable performance.
It is an object of the invention to provide a data/multi-media cable that has a specially designed interior support that accommodates conductors with a variety of AWG's, impedances, improved crush resistance, controlled NEXT, controlled electrical instability due to shielding, increased breaking strength, and allows the conductors, such as twisted pairs, to be spaced in a manner to achieve positive ACR ratios.
It is still another object of the invention to provide a cable that does not require individual shielding and that allows for the precise spacing of conductors such as twisted pairs and/or fiber optics with relative ease. In the present invention, the cable would include individual glass fibers as well as conventional metal conductors as the transmission medium that would be either together or separated in clearance channel chambers provided by the various shaped sections of the core support-separator.
Another embodiment of the invention includes having various geometrically shaped core support-separators with a central region that is either solid or partially solid. This includes the use of a foamed core and/or the use of a hollow center of the core, which in both cases significantly reduces the material required along the length of the finished cable. The effect of foaming and/or producing a support-separator with a hollow center portion should result in improved flammability of the overall cable by reducing the amount of material available as fuel for the UL 910 test, improved electrical properties for the individual non-optical conductors, and reduction of weight of the overall cable.
Additionally, the optical fibers could be present or later blown into center hollow core sections (where they exist) of the support-separators. The hollow center allows for the possible use with ABF—blown fiber ducts that allow for “post-installation” of the fiber (in any form).
Yet another embodiment of the invention allows for interior corrugated clearance channels provided by the sections of the core support-separators. This corrugated internal section has internal axial grooves that allow for separation of conductor pairs from each other or even separation of single conductors from each other as well as separation of optical conductors from conventional metal conductors. Alternatively, the edges of said grooves may allow for separation thus providing a method for uniformly locating or spacing the conductor pairs with respect to the channel walls instead of allowing for random floating of the conductor pairs.
Alternatively, depending on manufacturing capabilities, the use of a tape or polymeric binding sheet(s) may be necessary in lieu of extruded thermoplastic jacketing
Yet another related embodiment includes the use of a strength member together with, but outside of the core support-separator running parallel in the longitudinal direction along the length of the communications cable. In a related embodiment, the strength member could be the core support-separator itself, or in an additional related embodiment, the strength member could be inserted in the hollow center-portion of the core in lieu of a duct or ductlet for blown fiber.
It is to be understood that each of the embodiments above could include a flame-retarded, smoke suppressant version and that each could include the use of recycled or reground thermoplastics in an amount up to 100%.
A method of producing the communications cable, introducing any of the multi-shaped core separators as described above, into the cable assembly, is described as first passing a plurality of transmission media and a core through a first die which aligns the plurality of transmission media with surface features of the core and prevents or intentionally allows twisting motion of the core. Next, the method bunches the aligned plurality of transmission media and core using a second die which forces each of the plurality of the transmission media into contact with the surface features of the core that maintain a spatial relationship between each of a plurality of transmission media. Finally, the bunched plurality of transmission media and core are optionally twisted to close the cable, and the closed cable may be optionally jacketed.
Other desired embodiments, results, and novel features of the present invention will become more apparent from the following drawings and the accompanying preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a cross-section view of one embodiment of the cable support-separator that includes a symmetrical core with a central circular ring region with four extending rifled protrusions each extending in a preferred 90 degree separation from each other for optimum pair separation. The central ring portion optionally includes a hollow region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 1B is a cross-section view of a second embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIG. 1A , but also includes a second inner ring within the hollow region comprised of a different material than the outer ring for either increasing lubricity or friction with four extending rifled protrusions each extending in a preferred 90 degree separation from each other for optimum pair separation.
FIG. 1C is a cross-section view of a third embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIG. 1A , but also includes a second inner ring within the hollow region comprised of a different material than the outer ring for increasing friction utilizing rifled inner spatially arranged sections with four extending rifled protrusions each extending in a preferred 90 degree separation from each other for optimum pair separation.
FIG. 1D is a cross-section view of a third embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIG. 1C , but also includes the optional use of a organic or inorganic fibers including polyamide (for example Kevlar®) filling and an optional strength member within the second inner ring within the hollow region comprised of a different material than the outer ring as well as allowing for multiple separate multimode or single mode fiber optic units also contained within the same hollow region with four extending rifled protrusions each extending in a preferred 90 degree separation from each other for optimum pair separation.
FIG. 1E is a cross-section view of a fifth embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIG. 1B and also includes an inner pull tape for attaching optical fibers or metallic conductors wherein the tape optionally itself incorporates a grip or for which a grip is provided for future pulling of those communication media through the hollow region at some future time or during an installation with four extending rifled protrusions each extending in a preferred 90 degree separation from each other for optimum pair separation.
FIG. 1F is a cross-section view of a sixth embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIG. 1B but also two individual conductors (which may be twisted) inside the second inner ring which is smooth instead of rifled within the hollow region and comprised of a different material than the outer ring as well as allowing for multiple separate multimode or single mode fiber optic units also contained within the same hollow region with four extending rifled protrusions each extending in a preferred 90 degree separation from each other for optimum pair separation.
FIG. 1G is a cross-section view of a seventh embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIG. 1A with four extending rifled protrusions each extending in a preferred 90 degree separation from each other for optimum pair separation, but also includes the optional addition of one or more coaxial conductors contained in the center hollow region.
FIG. 2A is a cross-section view of an another embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIG. 1A but possesses 6 instead of 4 rifled protrusions each extending in a preferred degree separation from each other for optimum pair separation.
FIG. 2B is a cross-section view of another embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIGS. 1A and 2A but with an inner rifled ring section with as few as two and as many as six extending protrusions each extending in a preferred degree separation along the outer ring from each other for optimum pair separation.
FIG. 2C is a cross-section view of another embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIGS. 1A and 2A but with an inner smooth ring section with as few as two and as many as six extending protrusions each extending in a preferred degree separation along the outer ring from each other for optimum pair separation that optionally includes the optional addition of one or more conductors including optionally organic or inorganic fibers such as polyamide (for example Kevlar®) filling and an optional strength member within the second inner ring.
FIG. 2D is a cross-section view of another embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIGS. 1A and 2A but with an inner smooth ring section with as few as two and as many as six extending protrusions each extending in a preferred degree separation along the outer ring from each other for optimum pair separation that optionally includes the optional addition of one or more conductors including optionally organic or inorganic fibers such as polyamide (for example Kevlar®) filling and an optional strength member within the second inner ring. Also, between as few as one and as many as six of the extending projections, additional daisy-like spacers (as shown in FIG. 5A ) are placed which themselves allow for spacing of individual conductors or conductor pairs.
FIG. 2E is a cross-section view of another embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIGS. 1A and 2A but with an inner smooth ring section with as few as two and as many as six extending protrusions each extending in a preferred degree separation along the outer ring from each other for optimum pair separation that optionally includes the addition of one or more conductors including optionally organic or inorganic fibers such as polyamide (for example Kevlar®) filling and an optional strength member within the second inner ring. Also, between as few as one and as many as six of the extending projections are shown without the additional daisy-like spacers ( FIG. 5A ).
FIG. 2F is a cross-section view of another embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIGS. 1A and 2A but with an inner smooth ring section with as few as two and as many as six extending protrusions each extending in a preferred degree separation along the outer ring from each other for optimum pair separation that optionally includes the addition of one or more conductors including optionally organic or inorganic fibers such as polyamide (for example Kevlar®) filling and an optional strength member within the second inner ring. Also, between as few as one and as many as six of the extending projections, additional spacers comprised of a region which includes rounded lobes in a symmetric diamond-like geometry that defines as many as four separate regions for pairs that are properly separated in the final (often jacketed) cable design (as shown in FIG. 6A ) are placed which themselves allow for spacing of individual conductors or conductor pairs.
FIG. 3A is a cross-section view of another embodiment of the cable support-separator that includes a symmetrical core with a central circular ring region with four extending smooth protrusions, each protrusion extending less than those of FIGS. 1A through 2F , each again extending in a preferred 90 degree separation from each other for optimum pair separation The central ring portion optionally includes a hollow region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 3B is a cross-section view of another embodiment of the cable support-separator that includes a symmetrical core with a central circular ring region with four extending smooth protrusions, each protrusion extending less than those of FIGS. 1A through 2F , each again extending in a preferred 90 degree separation from each other for optimum pair separation and also includes a second inner ring within the hollow region comprised of a different material than the outer ring for either increasing lubricity or friction. The central ring portion optionally includes a hollow region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 3C is a cross-section view of another embodiment of the cable support-separator that includes a symmetrical core with a central circular ring region with four extending smooth protrusions, each protrusion extending less than those of FIGS. 1A through 2F , each again extending in a preferred 90 degree separation from each other for optimum pair separation and also includes also includes a second inner ring within the hollow region comprised of a different material than the outer ring for increasing friction utilizing rifled inner spatially arranged sections. The central ring portion optionally includes a hollow region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIGS. 3D and 3E are cross-section views of another embodiment of the cable support-separator that includes a symmetrical core with a central circular ring region with as few as two and as many as six extending smooth protrusions, each protrusion extending less than those of the series of FIGS. 1A through 2F , each again extending in a preferred separation from each other for optimum pair separation and also includes also includes a an optional second inner ring within the hollow region comprised of a different material than the outer ring for increasing friction utilizing rifled inner spatially arranged sections. The central ring portion optionally includes a hollow region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 3F is a cross-section view of another embodiment of the cable support-separator that includes a symmetrical core with a central circular ring region with no extending protrusions that includes also an optional second inner ring within the hollow region comprised of a different material than the outer ring for increasing friction utilizing rifled inner spatially arranged sections. The central ring portion optionally includes a hollow region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 4A is a cross-section view of another embodiment of the cable support-separator that includes a symmetrical core with a central circular ring region with four extending protrusions each protrusion extending less than those of FIGS. 1A through 2F and each with at least a single cross-like section extending outward from the circular ring section in a preferred 90 degree separation from each other for optimum pair separation. The central ring portion optionally includes a hollow region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 4B is a cross-section view of another embodiment of the cable support-separator that includes a symmetrical core with a central circular ring region and each with at least a single cross-like section extending from the circular ring section, each protrusion extending less than those of FIGS. 1A through 2F , each again extending in a preferred 90 degree separation from each other for optimum pair separation and also includes a second inner ring within the hollow region comprised of a different material than the outer ring for either increasing lubricity or friction. The central ring portion optionally includes a hollow region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 4C is a cross-section view of another embodiment of the cable support-separator that includes a symmetrical core with a central circular ring region and each with at least a single cross-like section extending from the circular ring section, each protrusion extending less than those of Figures through 2 F, each again extending in a preferred 90 degree separation from each other for optimum pair separation and also includes a second inner ring within the hollow region comprised of a different material than the outer ring for either increasing lubricity or friction. The inner portion of the hollow ring region here is optionally filled with inorganic or organic fibers such as polyamide fiber (Kevlar®) and at least four single or multimode finer optic units.
FIGS. 4D and 4E include a cross-section view of another embodiment of the cable support-separator that includes a symmetrical core with a central circular ring region with as few as two and as many as six extending protrusions each with at least a single cross-like section, each protrusion extending less than those of FIGS. 1A through 2F , each again extending in a preferred separation from each other for optimum pair separation and also includes also includes an optional second inner ring within the hollow region comprised of a different material than the outer ring for increasing friction utilizing rifled inner spatially arranged sections. The central ring portion optionally includes a hollow region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 4F includes a cross-section view of another embodiment of the cable support-separator includes a symmetrical core with a central circular ring region with no extending protrusions that includes also an optional second inner ring within the hollow region comprised of a different material than the outer ring for increasing friction utilizing rifled inner spatially arranged sections. The central ring portion optionally includes a hollow region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 5A is a cross-section view of another embodiment of the cable support-separator that includes a hollow four-petal or “daisy” shaped arrangement with a central core that may or may not be hollow. If the central region is hollow, the possibility again exists for that region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber. Coaxial or twisted pair conductors may also be introduced in that region.
FIG. 5B is a cross-section view of another embodiment of the cable support-separator that includes a solid four-petal or “daisy” shaped arrangement with a central core that may or may not be hollow. Each “petal” contains two hollow sections for additional optical or metallic conductor media. The central region is hollow allowing for the possibility that this region may act as an air blown fiber (ABF) duct which is available for filling with optical fiber. Coaxial or twisted pair conductors may also be introduced in that region.
FIG. 5C is a cross-section view of another embodiment of the cable support-separator that includes a solid four-petal or “daisy” shaped arrangement with a central core that may or may not be hollow. Each “petal” contains three hollow sections of differing diameters for additional optical or metallic conductor media. The central region is solid.
FIG. 5D is a cross-section view of another embodiment of the cable support-separator that includes a solid four-petal or “daisy” shaped arrangement with a central core that may or may not be hollow. Each “petal” contains three hollow sections of differing diameters for additional optical or metallic conductor media. In this case, the center hollow section of each petal is filled with an optical fiber unit. The central region is solid or optionally hollow.
FIGS. 6A , 6 B, 6 C are cross-sectional views of another set of embodiments of the cable support-separator that includes a circular ring region which is surrounded by rounded lobes in a symmetric diamond-like geometry that defines as many as four separate regions for pairs that are properly separated in the final (often jacketed) cable design. Again the central ring portion can optionally include a hollow region that may be used as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces. FIG. 6A has no inner ring, FIG. 6B has a smooth inner ring with optionally different material than the outer ring, and FIG. 6C has an inner ring with rifled sections. Each can optionally be used for coax or twisted pair as well as for fiber optic conductors in advance, during, or after installation.
FIG. 6D is a cross-sectional view of another embodiment of the cable support-separator that includes a circular ring region which is surrounded by rounded lobes in a symmetric diamond-like geometry that defines as many as four separate regions for pairs that are properly separated in the final (often jacketed) cable design. This design includes the optional addition of one or more conductors including optionally organic or inorganic fibers such as polyamide (for example Kevlar®) filling and an optional strength member within the second inner ring (that may or may not be rifled). Again the central ring portion can optionally include a hollow region that may be used as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 6E is a cross-sectional view of another embodiment of the cable support-separator that includes a circular ring region which is surrounded by rounded lobes in a symmetric diamond-like geometry that defines as many as four separate regions for pairs that are properly separated in the final (often jacketed) cable design. This design includes a center portion filled with a fiber optic unit as well as four separated conductor pairs in each of the regions defined by the symmetric diamond-like geometry of the cable support-separator. Again the central ring portion can optionally include a hollow region that may be used as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 6F is a cross-sectional view of another embodiment of the cable support-separator that includes a circular ring region which is surrounded by rounded lobes in a symmetric diamond-like geometry that defines as many as four separate regions for pairs that are properly separated in the final (often jacketed) cable design. This design includes a center portion with a second inner ring portion filled with a fiber optic unit or other conductors as well as four cross-like separators (see FIG. 7A ) in each of the regions defined by the symmetric diamond-like geometry of the cable support-separator within which another, up to four pairs of conductors are situated and separated by the cross-like separator. Again the central ring portion can optionally include a hollow region that may be used as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 7A is a cross-section view of another embodiment of the cable support-separator that includes a more conventional cross-like separator section with “rifled” sections extending outward into four quadrants away from the central region and is encased or covered within an outer insulated layer which is itself shaped in an identical cross except that the dimensions of this outer cross is larger than the rifled inner cross and functions as a “skin”. The inner cross-like portion may be metallized by utilizing electroless or electrolytic plating techniques over a thermoplastic film.
FIG. 7B is a cross-section view of another embodiment of the cable support-separator that includes the same more conventional cross-like separator section as with FIG. 7A except that this separator contains a shield that extends along the horizontal axis and optionally also along the vertical axis or both axes within the horizontal hollow portion of the cross-like separator. This shield is comprised of aluminum PET film and may be configured so that it is held within the outer cross-like separator.
FIG. 8A is a cross-section view of another embodiment of the cable support-separator that includes providing variations on a cross-like arrangement by adding “zig-zag” extensions that extend away from the central region. Again the cross-like “zig-zag” arrangement may be covered within an outer insulated layer which is itself shaped in an identical cross except that the dimensions of this outer cross are larger than the rifled inner cross and functions as a “skin”.
FIG. 8B is a cross-section view of another embodiment of the cable support-separator that includes providing variations on a cross-like arrangement by adding “sickle-like” extensions that extend away from the central region. Again the cross-like and sickle-like sections arrangement may be covered within an outer insulated layer which is itself shaped in an identical cross except that the dimensions of this outer cross are larger than the rifled inner cross and functions as a “skin”.
FIG. 9 is a cross-sectional view of another embodiment with several hollow regions for blown fiber or any transmission media for present, future, or concurrent installations using the support-separator alone or in combination with a cable.
FIGS. 10A and 10B are cross-sectional views of another set of embodiments of the cable support-separator that includes a circular ring region which is surrounded by semi-rounded lobes in a symmetric star-like geometry that defines as many as four separate regions for pairs that are properly separated in the final (often jacketed) cable design. Again the central ring portion can optionally include a hollow region that may be used as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces. FIGS. 10A and 10B include views of optionally filled inner hollow regions such that each can optionally be used for coax or twisted pair as well as for fiber optic conductors (in advance, during or after installation). FIG. 10A includes a view of this design including the optional addition of one or more conductors including optionally organic or inorganic fibers such as polyamide (for example Kevlar®) filling and an optional strength member within the second inner ring (that may or may not be rifled). FIG. 10B includes a view of this design including the optional addition of coaxial cable in the hollow center region.
DETAILED DESCRIPTION
The following description will further help to explain the inventive features of the cable and the interior support portion of the cable.
FIG. 1A is a cross-section view of one embodiment of the cable support-separator that includes a symmetrical core with a central circular ring region ( 100 ) with four extending rifled protrusions ( 110 , 112 , 114 , 116 ) each extending in a preferred 90 degree separation from each other for optimum pair separation. The optimum pair separation is gained by placing pairs between the four extending rifled protrusions in regions 120 , 122 , 124 , and 126 . The central circular ring portion ( 100 ) optionally includes a hollow region ( 130 ) to act as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 1B is a cross-section view of a second embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIG. 1A , but also includes a second inner ring ( 140 ) within the hollow region comprised of a different material than the outer ring for either increasing lubricity or friction with four extending rifled protrusions each extending in a preferred 90 degree separation from each other for optimum pair separation.
FIG. 1C is a cross-section view of a third embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIG. 1A , but also includes a second inner ring within the hollow region comprised of a different material than the outer ring for increasing friction utilizing rifled inner spatially arranged sections ( 150 ) with four extending rifled protrusions each extending in a preferred 90 degree separation from each other for optimum pair separation.
FIG. 1D is a cross-section view of a fourth embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIG. 1C , but also includes the optional use of a organic or inorganic fibers ( 160 ) including polyamide (for example Kevlar®) filling and an optional strength member within the second inner ring within the hollow region comprised of a different material than the outer ring as well as allowing for multiple separate multimode or single mode fiber optic units ( 162 ) also contained within the same hollow region with four extending rifled protrusions each extending in a preferred 90 degree separation from each other for optimum pair separation.
FIG. 1E is a cross-section view of a fifth embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIG. 1B and also includes an inner pull tape ( 170 ) for attaching optical fibers or metallic conductors wherein the tape optionally itself incorporates a grip or for which a grip is provided for future pulling of those communication media through the hollow region at some future time or during an installation with four extending rifled protrusions each extending in a preferred 90 degree separation from each other for optimum pair separation.
FIG. 1F is a cross-section view of a sixth embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIG. 1B but also two individual conductors ( 180 and 182 ) (which may be twisted) inside the second inner ring which is smooth instead of rifled within the hollow region and comprised of a different material than the outer ring as well as allowing for multiple separate multimode or single mode fiber optic units also contained within the same hollow region with four extending rifled protrusions each extending in a preferred 90 degree separation from each other for optimum pair separation.
FIG. 1G is a cross-section view of a seventh embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIG. 1A with four extending rifled protrusions each extending in a preferred 90 degree separation from each other for optimum pair separation, but also includes the optional addition of one or more coaxial conductors ( 190 ) with a tinned copper braided shield ( 192 ).
FIG. 2A is a cross-section view of an another embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIG. 1A but possesses 6 instead of 4 rifled protrusions ( 210 , 212 , 214 , 216 , 218 , 220 ) each extending in a preferred degree separation from each other for optimum pair separation. The optimum pair separation is gained by placing pairs between the six extending rifled protrusions in regions 230 , 232 , 234 , 236 , 238 , and 240 . The central circular ring portion ( 200 ) optionally includes a hollow region ( 250 ) to act as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 2B is a cross-section view of another embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIGS. 1A and 2A , with as few as two and as many as six extending protrusions each extending in a preferred degree separation along the outer ring from each other for optimum pair separation, but also includes a second inner ring within the hollow region comprised of a different material than the outer ring for increasing friction utilizing rifled inner spatially arranged sections ( 260 ).
FIG. 2C is a cross-section view of another embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIGS. 1A and 2A but with an inner smooth ring section ( 270 ) with as few as two and as many as six extending protrusions each extending in a preferred degree separation along the outer ring from each other for optimum pair separation that optionally includes the optional addition of one or more conductors ( 274 ) including optionally organic or inorganic fibers such as polyamide (for example Kevlar®) filling and an optional strength member ( 272 ) within the second inner ring.
FIG. 2D is a cross-section view of another embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIGS. 1A and 2A but with an inner smooth ring section with as few as two and as many as six extending protrusions each extending in a preferred degree separation along the outer ring from each other for optimum pair separation that optionally includes the optional addition of one or more conductors including optionally organic or inorganic fibers such as polyamide (for example Kevlar®) filling and an optional strength member within the second inner ring. Also, between as few as one and as many as six of the extending projections, additional daisy-like spacers ( 280 ) (as shown in FIG. 4A ) are placed which themselves allow for spacing of individual conductors or conductor pairs ( 282 ).
FIG. 2E is a cross-section view of another embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIGS. 1A and 2A but with an inner smooth ring section with as few as two and as many as six extending protrusions each extending in a preferred degree separation along the outer ring from each other for optimum pair separation that optionally includes the optional addition of one or more conductors including optionally organic or inorganic fibers such as polyamide (for example Kevlar®) filling and an optional strength member within the second inner ring. Also, between as few as one and as many as six of the extending projections are shown without ( 284 ) the additional daisy-like spacers ( FIG. 5A ).
FIG. 2F is a cross-section view of another embodiment of the cable support-separator that includes the same symmetrical core with a central circular ring region as for FIGS. 1A and 2A but with an inner smooth ring section with as few as two and as many as six extending protrusions each extending in a preferred degree separation along the outer ring from each other for optimum pair separation that optionally includes the optional addition of one or more conductors including optionally organic or inorganic fibers such as polyamide (for example Kevlar®) filling and an optional strength member within the second inner ring. Also, between as few as one and as many as six of the extending projections, additional spacers ( 290 ) comprised of a circular ring region which is surrounded by rounded lobes in a symmetric diamond-like geometry that defines as many as four separate regions for pairs that are properly separated in the final (often jacketed) cable design (as shown in FIG. 6A ) are placed which themselves allow for spacing of individual conductors or conductor pairs.
FIG. 3A is a cross-section view of another embodiment of the cable support-separator that includes a symmetrical core with a central circular ring region ( 300 ) with four extending smooth protrusions ( 310 , 312 , 314 , 316 ), each protrusion extending less than those of FIGS. 1A through 2F , each again extending in a preferred 90 degree separation from each other for optimum pair separation The central ring portion optionally includes a hollow region ( 320 ) to act as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 3B is a cross-section view of another embodiment of the cable support-separator that includes a symmetrical core with a central circular ring region with four extending smooth protrusions, each protrusion extending less than those of FIGS. 1A through 2F , each again extending in a preferred 90 degree separation from each other for optimum pair separation and also includes a second inner ring ( 330 ) within the hollow region comprised of a different material than the outer ring for either increasing lubricity or friction. The central ring portion optionally includes a hollow region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 3C is a cross-section view of another embodiment of the cable support-separator that includes a symmetrical core with a central circular ring region with four extending smooth protrusions, each protrusion extending less than those of FIGS. 1A through 2F , each again extending in a preferred 90 degree separation from each other for optimum pair separation and also includes also includes a second inner ring within the hollow region comprised of a different material than the outer ring for increasing friction utilizing rifled inner spatially arranged sections ( 340 ). The central ring portion optionally includes a hollow region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIGS. 3D and 3E are cross-section views of another embodiment of the cable support-separator that includes a symmetrical core with a central circular ring region with as few as two ( 370 and 372 in FIG. 3E ) and as many as six extending smooth protrusions ( 350 , 352 , 354 , 356 , 358 , 360 in FIG. 3D ), each protrusion extending less than those of the series of FIGS. 1A through 2F , each again extending in a preferred separation from each other for optimum pair separation and also includes also includes a an optional second inner ring within the hollow region comprised of a different material than the outer ring for increasing friction utilizing rifled inner spatially arranged sections. The central ring portion optionally includes a hollow region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 3F is a cross-section view of another embodiment of the cable support-separator that includes a symmetrical core with a central circular ring region with no extending protrusions ( 380 ) that includes also an optional second inner ring within the hollow region comprised of a different material than the outer ring for increasing friction optionally utilizing rifled inner spatially arranged sections. The central ring portion optionally includes a hollow region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 4A is a cross-section view of another embodiment of the cable support-separator that includes a symmetrical core with a central circular ring region ( 400 ) with four extending protrusions ( 410 , 412 , 414 , 416 ) each protrusion extending less than those of FIGS. 1A through 2F and each with at least a single cross-like section ( 420 , 422 , 424 , 426 ) extending outward from the circular ring section in a preferred 90 degree separation from each other for optimum pair separation. The central ring portion optionally includes a hollow region ( 430 ) to act as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 4B is a cross-section view of another embodiment of the cable support-separator that includes a symmetrical core with a central circular ring region and each with at least a single cross-like section extending from the circular ring section, each protrusion extending less than those of FIGS. 1A through 2F , each again extending in a preferred 90 degree separation from each other for optimum pair separation and also includes a second inner ring ( 440 ) within the hollow region comprised of a different material than the outer ring for either increasing lubricity or friction. The central ring portion optionally includes a hollow region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 4C is a cross-section view of another embodiment of the cable support-separator that includes a symmetrical core with a central circular ring region and each with at least a single cross-like section extending from the circular ring section, each protrusion extending less than those of Figures through 2 F, each again extending in a preferred 90 degree separation from each other for optimum pair separation and also includes a second inner ring within the hollow region comprised of a different material than the outer ring for either increasing lubricity or friction. The inner portion of the hollow ring region here is optionally filled with inorganic or organic fibers ( 450 ) such as polyamide fiber (Kevlar®) and at least four single or multimode finer optic units ( 460 , 462 , 464 , and 466 ).
FIGS. 4D and 4E include a cross-section view of another embodiment of the cable support-separator that includes a symmetrical core with a central circular ring region with as few as two ( 470 and 472 in FIG. 4E ) and as many as six ( 450 , 452 , 454 , 456 , 458 , and 460 in FIG. 4D ) extending protrusions each with at least a single cross-like section, each protrusion extending less than those of FIGS. 1A through 2F , each again extending in a preferred separation from each other for optimum pair separation and also includes also includes an optional second inner ring within the hollow region comprised of a different material than the outer ring for increasing friction utilizing rifled inner spatially arranged sections. The central ring portion optionally includes a hollow region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 4F includes a cross-section view of another embodiment of the cable support-separator includes a symmetrical core with a central circular ring region with no extending protrusions ( 480 ) that includes also an optional second inner ring within the hollow region comprised of a different material than the outer ring for increasing friction utilizing rifled inner spatially arranged sections. The central ring portion optionally includes a hollow region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 5A is a cross-section view of another embodiment of the cable support-separator that includes a hollow four-petal ( 510 , 512 , 514 , and 516 ) or “daisy” shaped arrangement with a central core ( 500 ) that may or may not be hollow ( 520 shown hollow). If the central region is hollow, the possibility again exists for that region to act as an air blown fiber (ABF) duct which is available for filling with optical fiber. Coaxial or twisted pair conductors may also be introduced in that region.
FIG. 5B is a cross-section view of another embodiment of the cable support-separator that includes a solid four-petal ( 540 , 542 , 544 , and 546 ) or “daisy” shaped arrangement with a central core ( 530 ) that may or may not be hollow ( 532 shown hollow). Each “petal” contains two hollow sections ( 550 and 552 ) for additional optical or metallic conductor media. The central region ( 532 ) is hollow allowing for the possibility that this region may act as an air blown fiber (ABF) duct which is available for filling with optical fiber. Coaxial or twisted pair conductors may also be introduced in that region.
FIG. 5C is a cross-section view of another embodiment of the cable support-separator that includes a solid four-petal or “daisy” shaped arrangement with a central core ( 560 ) that may or may not be hollow. Each “petal” contains three hollow sections ( 570 , 572 , and 574 ) of differing diameters for additional optical or metallic conductor media. The central region ( 560 ) is solid.
FIG. 5D is a cross-section view of another embodiment of the cable support-separator that includes a solid four-petal or “daisy” shaped arrangement with a central core that may or may not be hollow. Each “petal” contains three hollow sections of differing diameters for additional optical or metallic conductor media. In this case, the center hollow section of each petal is filled with an optical fiber unit ( 580 ). The central region is solid or optionally hollow.
FIGS. 6A , 6 B, 6 C are cross-sectional views of another set of embodiments of the cable support-separator that includes a circular ring region ( 600 ) which is surrounded by rounded lobes ( 610 , 612 , 614 , and 616 ) in a symmetric diamond-like geometry that defines as many as four separate regions for pairs that are properly separated in the final (often jacketed) cable design. Again the central ring portion can optionally include a hollow region ( 620 ) that may be used as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces. FIG. 6A has no inner ring, FIG. 6B has a smooth inner ring ( 630 ) with optionally different material than the outer ring, and FIG. 6C has an inner ring ( 640 ) with rifled sections ( 642 ). Each can optionally be used for coax or twisted pair as well as for fiber optic conductors in advance, during, or after installation.
FIG. 6D is a cross-sectional view of another embodiment of the cable support-separator that includes a circular ring region which is surrounded by rounded lobes in a symmetric diamond-like geometry that defines as many as four separate regions for pairs that are properly separated in the final (often jacketed) cable design. This design includes the optional addition of one or more conductors including optionally organic or inorganic fibers such as polyamide (for example Kevlar®) filling and an optional strength member ( 650 ) within the second inner ring (that may or may not be rifled). Again the central ring portion can optionally include a hollow region that may be used as an air blown fiber (ABF) duct which is available for filling with optical fiber ( 660 , 662 , 664 , and 666 ) which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 6E is a cross-sectional view of another embodiment of the cable support-separator that includes a circular ring region which is surrounded by rounded lobes in a symmetric diamond-like geometry that defines as many as four separate regions for pairs that are properly separated in the final (often jacketed) cable design. This design includes a center portion filled with a fiber optic unit ( 670 ) as well as four separated conductor pairs ( 680 , 682 , 684 , and 686 ) in each of the regions defined by the symmetric diamond-like geometry of the cable support-separator. Again the central ring portion can optionally include a hollow region that may be used as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 6F is a cross-sectional view of another embodiment of the cable support-separator that includes a circular ring region which is surrounded by rounded lobes in a symmetric diamond-like geometry that defines as many as four separate regions for pairs that are properly separated in the final (often jacketed) cable design. This design includes a center portion with a second inner ring portion ( 690 ) filled with a fiber optic unit ( 692 ) or other conductors as well as four cross-like separators ( 694 ) (see FIG. 7A ) in each of the regions defined by the symmetric diamond-like geometry of the cable support-separator within which another, up to four pairs of conductors ( 696 ) are situated and separated by the cross-like separator. Again the central ring portion can optionally include a hollow region that may be used as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces.
FIG. 7A is a cross-section view of another embodiment of the cable support-separator that includes a more conventional cross-like separator section ( 700 ) with “rifled” sections ( 702 and 704 , for example) extending outward into four quadrants ( 710 , 712 , 714 , and 716 ) away from the central region ( 700 ) and is encased or covered within an outer insulated layer ( 720 ) which is itself shaped in an identical cross except that the dimensions of this outer cross is larger than the rifled inner cross and functions as a “skin”. The inner cross-like portion may be metallized by utilizing electroless or electrolytic plating techniques over a thermoplastic film.
FIG. 7B is a cross-section view of another embodiment of the cable support-separator that includes the same more conventional cross-like separator section as with FIG. 7A except that this separator contains a shield ( 730 ) that extends along the horizontal axis and optionally also along the vertical axis or both axes within the horizontal hollow portion ( 740 ) of the cross-like separator. This shield is comprised of aluminum PET film and may be configured so that it is held within the outer cross-like separator ( 720 ).
FIG. 8A is a cross-section view of another embodiment of the cable support-separator that includes providing variations on a cross-like arrangement by adding “zig-zag” extensions ( 810 , 812 , and 814 , for example) that extend away from the central region ( 800 ). Again the cross-like “zig-zag” arrangement may be covered within an outer insulated layer which is itself shaped in an identical cross except that the dimensions of this outer cross are larger than the rifled inner cross and functions as a “skin”. This design optionally includes four separated conductor pairs ( 820 , 822 , 824 , and 826 ) in each of the regions defined by the symmetric diamond-like geometry of the cable support-separator.
FIG. 8B is a cross-section view of another embodiment of the cable support-separator that includes providing variations on a cross-like arrangement by adding “sickle-like” extensions ( 830 , 832 , 834 , and 836 ) that extend away from the central region. Again the cross-like and sickle-like sections arrangement may be covered within an outer insulated layer which is itself shaped in an identical cross except that the dimensions of this outer cross are larger than the rifled inner cross and functions as a “skin”. This design optionally includes four separated conductor pairs ( 820 , 822 , 824 , and 826 ) in each of the regions defined by the symmetric diamond-like geometry of the cable support-separator.
FIG. 9 is a cross-sectional view of another embodiment ( 900 ) with several hollow regions ( 910 , 912 , 914 , for example) for blown fiber or any transmission media for present, future, or concurrent installations using the support-separator alone or in combination with a cable.
FIGS. 10A and 10B are cross-sectional views of another set of embodiments of the cable support-separator that includes a circular ring region ( 1000 ) which is surrounded by semi-rounded lobes ( 1010 , 1012 , 1014 , and 1016 ) in a symmetric star-like geometry that defines as many as four separate regions for pairs ( 1020 , 1022 , 1024 , and 1026 ) that are properly separated in the final (often jacketed) cable design. Again the central ring portion can optionally include a hollow region ( 1030 ) that may be used as an air blown fiber (ABF) duct which is available for filling with optical fiber which is comprised of solid, semi-solid, foamed or hollow polymeric smooth internal and external surfaces. FIGS. 10A and 10B include views of optionally filled inner hollow regions such that each can optionally be used for coax or twisted pair as well as for fiber optic conductors (in advance, during or after installation). FIG. 10A includes a view of this design including the optional addition of one or more conductors including optionally organic or inorganic fibers such as polyamide (for example Kevlar®) filling and an optional strength member within the second inner ring (that may or may not be rifled). FIG. 10B includes a view of this design that includes the optional addition of coaxial cable ( 1002 ) in the hollow center region. The central circular region ( 1001 ) is of a slightly larger size than that shown in FIG. 10A in order to allow for coaxial cable in the central hollow region of the separator. | A high performance communications cable with core support-separators having various shaped profiles defining and maintaining a space between transmission multi-media or transmission multi-media pairs. The core may be of a conductive or insulative material. The central core region includes a hollow opening or duct for blown fiber (ABF). The core support-separator can be interior to the cable jacket or without the benefit of a jacket. A thin layer of material can act as a type of skin for future mechanical protection. The specially shaped core support-separator has a central region that is either solid, partially solid, foamed, with a solid skin over the foam or hollow itself. The cable may include a plurality of shaped sections that extend outward from the central region along the length of the central region. Each of the defined clearance channels allow for disposal therein of conductors and optical fibers. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to imidazo[4,5-c]quinoline amine compounds. In another aspect this invention relates to immunomodulator compounds. In other aspects this invention relates to pharmaceutical compositions containing such compounds, and pharmacological methods of using such compounds.
2. Description of the Related Art
Certain 1H-imidazo[4,5-c]quinolin-4-amines are known as antiviral agents and/or as immunomodulators. Such compounds are disclosed e.g., in U.S. Pat. Nos. 4,689,338, 4,929,624, 5,037,986, 5,266,575, 5,268,376, 5,346,905, European Patent Application No. 0,385,630 A2 and WO92/15582 (all to Gerster et al.). Commonly assigned copending application 08/092,002 (Lindstrom et al.) filed Jul. 15, 1993, now abandoned, discloses immunomodulator imidazopyridine amines of the formula ##STR1##
R 1 is selected from the group consisting of hydrogen; CHR x R y wherein R x is hydrogen and R y is selected from the group consisting of straight chain, branched chain, or cyclic alkyl containing one to about ten carbon atoms, straight chain or branched chain alkenyl containing two to about ten carbon atoms, straight chain or branched chain hydroxyalkyl containing one to about six carbon atoms, alkoxyalkyl wherein the alkoxy moiety contains one to about four carbon atoms and the alkyl moiety contains one to about six carbon atoms, and phenylethyl; and --CH═CR z R z wherein each R z is independently straight chain, branched chain, or cyclic alkyl of one to about six carbon atoms.
U.S. Pat. No. 5,352,784 (Nickolaides et al.) discloses immunomodulator 6,7-fused cycloalkylimidazopyridine amines.
SUMMARY OF THE INVENTION
1H-Imidazo[4,5-c]quinolin-4-amines are compounds of the general skeletal Formula I, having the numbering system shown: ##STR2## This invention provides compounds and pharmaceutically acceptable salts thereof formally derived by bridging the 1- and 2-positions of 1H-imidazo[4,5-c]quinolin-4-amines. In particular this invention provides compounds of Formula II ##STR3## wherein R, Z, and q are as defined in detail below, and pharmaceutically acceptable salts thereof.
This invention also provides a pharmaceutical formulation comprising: (i) a compound of Formula II in an amount effective to induce interferon biosynthesis in an animal, and (ii) a pharmaceutically acceptable carrier. This invention further provides a method of inducing interferon biosynthesis in an animal, comprising the step of administering to said animal a compound of Formula II in an amount effective to induce said interferon biosynthesis.
DETAILED DESCRIPTION OF THE INVENTION
This invention provides compounds of Formula II wherein Z is selected from the group consisting of:
--(CH 2 ) n -- wherein n is 1 to 4,
--(CH 2 ) a --C(R 1 R 2 )(CH 2 ) b --, wherein a and b are integers and a+b is 0 to 3, R 1 is hydrogen or alkyl of 1 to 4 carbon atoms, and R 2 is selected from the group consisting of alkyl of 1 to 4 carbon atoms, hydroxy, --OR 3 wherein R 3 is alkyl of 1 to 4 carbon atoms, and --NR 4 R' 4 wherein R 4 and R' 4 are independently hydrogen or alkyl of 1 to 4 carbon atoms,
--(CH 2 ) a --(Y)--(CH 2 ) b -- wherein a and b are integers and a+b is 0 to 3, and Y is O, S, or --NR 5 -- wherein R 5 is hydrogen or alkyl of 1 to 4 carbon atoms,
and wherein q is 0 or 1 and R is selected from the group consisting of alkyl of 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms, and halogen,
and pharmaceutically acceptable salts thereof.
When Z is --(CH 2 ) n -- as defined above it is preferably alkylene having 1, 2, or 3 carbon atoms. When Z is --(CH 2 ) a --C(R 1 R 2 )(CH 2 ) b -- as defined above R 1 is preferably hydrogen and R 2 is preferably alkyl of 1 to 4 carbon atoms, most preferably methyl. When Z is --(CH 2 ) a --(Y)--(CH 2 ) b -- as defined above Y is preferably O, and when Y is O a+b is preferably 1.
Preferred compounds of the invention include: ##STR4##
Reaction Scheme I illustrates preparation of the compounds of the invention. The unsubstituted compound of Formula XI is a known commercially available compound and other compounds of Formula XI can be prepared by methods known to those skilled in the art and disclosed, e.g., in Chem. Ber. 1927, 60, 1108 (Kohler) and J. Heterocyclic Chem. 1988, 25, 857 (Kappe).
In step (i) a 3-nitroquinoline-2,4-disulfonate is first prepared by reacting a 2,4-dihydroxy-3-nitroquinoline with a sulfonyl halide or preferably a sulfonic anhydride. Suitable sulfonyl halides include alkylsulfonyl halides such as methanesulfonyl chloride and trifluoromethanesulfonyl chloride, and arylsulfonyl halides such as benzenesulfonyl chloride, p-bromobenzenesulfonyl chloride, and p-toluenesulfonyl chloride. Suitable sulfonic anhydrides include those corresponding to the above-mentioned sulfonyl halides. A particularly preferred sulfonic anhydride is trifluoromethanesulfonic anhydride.
Reaction conditions preferably involve first combining a compound of Formula XI with a base, preferably an excess of a tertiary amine base (e.g., a trialkylamine base such as triethylamine) and preferably in an appropriate solvent such as dichloromethane and then adding the sulfonyl halide or the sulfonic anhydride. The addition is preferably carried out in a controlled fashion (e.g., dropwise) and at a reduced temperature (e.g., at about 0° C.). ##STR5##
The disulfonate is then reacted with tert-butylamine, preferably in the presence of an excess of a tertiary amine base in a solvent such as dichloromethane to afford a compound of Formula XII. The reaction can be carried out by adding the tertiary amine base to the reaction mixture resulting from the first porion of step (i), cooling to a reduced temperature (e.g., 0° C.) and adding the tert-butylamine in a controlled fashion (e.g., dropwise). The reaction can also be carried out by adding the tert-butylamine to a solution of the disulfonate and a tertiary amine base in a solvent such as dichloromethane. The reaction can be run at relatively low temperatures, e.g., about 0° C., in order to decrease the amount of undesired 2-aminated and 2,4-diaminated side products. It is sometimes necessary or desirable to heat the reaction mixture after the addition in order to complete the reaction.
In step (ii) the compound of Formula XII is reacted with dibenzylamine. The reaction can be carried out by placing the starting material and the dibenzylamine in an inert solvent such as benzene, toluene, or xylene, and heating at a temperature and for a time sufficient to cause displacement of the sulfonate group by the dibenzylamine, such temperature and time being readily selected by those skilled in the art. The tert-butyl group is then removed by heating in a polar solvent: such as methanol in the presence of an acid such as hydrochloric acid.
The nitro group is then reduced to an amino group. Methods for such a reduction are well known to those skilled in the art:. A preferred method involves in situ generation of Ni 2 B from sodium borohydride and NiCl 2 in methanol to afford a reducing agent solution. The nitro compound is added to the reducing agent solution to effect reduction of the nitro group. The product is a compound of Formula XIII.
In step (iii) a compound of Formula XIII is reacted with acetic acid or an equivalent thereof to afford the cyclized compound of Formula XIV. Suitable equivalents to acetic acid include corresponding acetyl halides and orthoesters. When using acetic acid or an orthoester equivalent the reaction can be run in the absence of solvent or in an inert solvent such as xylene or toluene with sufficient heating (e.g., at about 80°-150° C. depending on the solvent if any) to drive off any alcohol or water formed as a side product of the reaction. When using an acetyl halide the reaction is preferably run in acetic acid with heating.
In step (iv) the cyclized compound of Formula XIV is first substituted at the 1-position with an alkoxymethyl group (--CH 2 OR' wherein R' is alkyl such as ethyl) in order to protect the 1-nitrogen. The substitution can be carried out by treating the compound of Formula XIV with sodium hydride and a halomethylalkyl ether such as chloromethyl ethyl ether. The resulting 1-protected compound is then substituted on the 2-methyl group with a moiety of the formula --ZCl to afford a compound of Formula XV. This can be accomplished by metalating the 2-methyl group of the 1-protected compound, e.g., by treating with n-butyl lithium in tetrahydrofuran, then adding an alkylating agent of the formula X'--ZCl wherein X' is a more facile leaving group than chloro (e.g., X' can be bromo). Another suitable method of substituting on the 2-methyl group involves metalating, reacting with an epoxide such as ethylene oxide, and converting the resulting 2-(hydroxyalkyl) compound to the corresponding halide by reacting with a chlorinating agent such as thionyl chloride in an inert solvent.
In step (v) the 1-position of a compound of Formula XV is deprotected, e.g., by heating in the presence of HCl in a solvent such as methanol. The resulting 1-hydrogen compound is then cyclized by formal displacement of the chloro group by the 1-nitrogen. Treating with sodium iodide in a polar solvent such as acetone in the presence of a neutralizing base (e.g., potassium carbonate) is a suitable means for affecting cyclization. A compound of Formula XVI results.
In step (vi) the compound of Formula XVI is hydrogenolyzed to afford the corresponding 4-amino compound of Formula II. Conventional well known catalytic hydrogenation conditions are suitable. Preferred conditions involve heating in formic acid in the presence of Pd(OH) 2 /C.
Reaction Scheme II shows a route to certain compounds of the invention not amenable to preparation via Reaction Scheme I. ##STR6##
In step (i) a compound of Formula XIII is cyclized using formic acid or an equivalent thereof such as an orthoformate (e.g., triethylorthoformate) to provide a compound of Formula XXI (see, e.g., step (iii) of Reaction Scheme I). In step (ii) the compound of Formula XXI is protected at the 1-position as described above in connection with step (iv) of Reaction Scheme I. The protected product is then formylated at the 2-position by first metalating in a polar solvent such as tetrahydrofuran, e.g., reacting with n-butyllithium, and then treating with formaldehyde. Step (iii) involves homologating the 2-substituent of the compound of Formula XXII, e.g., by reacting with 1-bromo-2-(triphenylmethoxy)ethane. The product of Formula XXIII can be carried on to a compound of Formula II by acid catalyzed hydrolysis of the protecting groups to afford a compound of Formula XXIV, conversion of the hydroxyl group on the 2-substituent to an appropriate leaving group, cyclization (e.g., as described above in connection with step (v) of Reaction Scheme I), and reductive cleavage as described above in connection with step (vi) of Reaction Scheme I.
Compounds of Formula II not amenable to being prepared via the routes illustrated in Reaction Schemes I or II, or otherwise described herein can be prepared using variants of the illustrated schemes involving well known synthetic alternatives, alteration of the order of steps, and the like.
The product compound of Formula II can be isolated by the conventional means disclosed in U.S. Pat. No. 4,689,338 (Gerster), such as, for example, removal of the solvent and recrystallization from an appropriate solvent (e.g., N,N-dimethylformamide) or solvent mixture, or by dissolution in an appropriate solvent (such as methanol) and re-precipitation by addition of a second solvent in which the compound is insoluble.
A compound of Formula II can be used as an antiviral agent itself or it can be used in the form of a pharmaceutically acceptable salt such as a hydrochloride, dihydrogen sulfate, trihydrogen phosphate, hydrogen nitrate, methanesulfonate or a salt of another pharmaceutically acceptable acid. A pharmaceutically acceptable salt of a compound of Formula II can be readily prepared, generally by reaction of the compound with an equimolar amount of a relatively strong acid, preferably an inorganic acid such as hydrochloric, sulfuric, or phosphoric acid, or an organic acid such as methanesulfonic acid, in a polar solvent. Isolation of the salt is facilitated by the addition of a solvent, such as diethyl ether, in which the salt is insoluble.
A compound of the invention can be formulated for the various routes of administration (e.g., oral administration by tablet, capsule, oral suspension, or the like, topical, transdermal, or parenteral) by combining a therapeutically effective amount of a compound of Formula II with an appropriate pharmaceutically acceptable vehicle including any adjuvants and excipients suitable for the selected dosage form. Suitable formulations include parenteral solutions, topical creams, gels, and ointments, and oral tablets and capsules. Methods of manufacture of such pharmaceutical compositions are well known to those skilled in the art and disclosed, e.g., in Remington's Pharmaceutical Sciences, 18th Edition, 1990 Mack Publishing Company, A. R. Gennaro, Editor. Consequently, particular formulations suitable for a selected route of administration can be readily identified and prepared by those skilled in the art. A solid dosage form, for example, contains a compound of Formula II, and one or more diluents (e.g., dicalcium phosphate, calcium sulfate, lactose, mannitol, cellulose, kaolin, sodium chloride, starch, sucrose, inositol, sorbitol), binders (e.g., starch, gelatin, sucrose, glucose, dextrose, molasses, lactose, natural and synthetic gums), lubricants (e.g., talc, magnesium stearate, calcium stearate, stearic acid, hydrogenated vegetable oils, polyethylene glycols), disintegrants (e.g., corn starch, potato starch, clays, cellulose, alginates), coloring agents, and flavoring agents. A parenteral solution contains a compound of Formula II and a pharmaceutically acceptable aqueous vehicle including suitable excipients, such as acids (hydrochloric acid, lactic acid, acetic acid, aspartic acid or mixtures thereof) or bases (sodium hydroxide) sufficient to achieve a pH of 2 to about 6, and tonicity adjusters (e.g., sorbitol or glycerin) in order that the formulation is isotonic with serum. Topical or transdermal formulations contain a compound of Formula II in a cream, ointment, or a pressure sensitive adhesive composition. A cream can contain emollients (e.g., cetyl alcohol, stearyl alcohol, petrolatum, light mineral oil, acetylated lanolin), emulsifiers (e.g., nonionic surfactants such as polysorbate 60, sorbitan monostearate), thickeners (e.g., montmorillonite clays or long chain alcohols such as cetearyl alcohol, cetyl alcohol, and stearyl alcohol), and preservatives (e.g., methylparaben, propylparaben, benzyl alcohol) in amounts readily selected by those skilled in the art. An ointment contains an ointment base (e.g., polyethylene glycol, petrolatum) and emollients and thickeners.
The amount of compound of Formula II that constitutes a therapeutically effective amount will vary according to the particular compound used, the desired therapeutic effect, the condition being treated, the dosing regimen, and the route of administration. Generally, a compound of Formula II will be present in a parenteral formulation in an amount of about 0.1 to about 10 percent by weight based on the total weight of the formulation. Similarly an oral tablet or capsule will generally contain about 0.5 to about 50 percent by weight; and a topical or transdermal formulation will contain about 0.1 to about 10 percent by weight. Particular formulations will be easily selected by those skilled in the art.
A number of compounds of Formula II were tested and found to induce biosynthesis of interferon in human cells and in mice. These results suggest that at least certain compounds of the invention might be useful in treating viral diseases (e.g., hepatitis, herpes, warts) and diseases such as rheumatoid arthritis, eczema, psoriasis, multiple sclerosis, essential thrombocythaemia, cancer such as basal cell carcinoma, and other neoplastic diseases.
The examples below are intended to illustrate the invention. The structures were confirmed by nuclear magnetic resonance spectroscopy.
EXAMPLE 1
8,9,10,11-Tetrahydropyrido[1',2':1,2[imidazo[4,5-c]quinolin-6-amine
Part A
Triethylamine (84 mL, 0.6 mole) was added to a suspension of 3-nitro-2,4-quinolinediol (40 g, 0.194 mole) in methylene chloride (1200 mL). The resulting solution was cooled in an ice bath and trifluoromethanesulfonic anhydride (67.2 mL, 0.40 mole) was added. After the addition was complete, the reaction was heated on a steam bath for 10 minutes then once again cooled in an ice bath. Tert-butylamine (42 mL, 0.4 mole) was added then the reaction was heated on a steam bath for 15 minutes. The reaction mixture was washed with aqueous sodium bicarbonate (500 mL), dried over magnesium sulfate then concentrated under vacuum. The concentrate was put through a layer of silica gel and the silica gel was eluted with methylene chloride. The methylene chloride solution was evaporated under vacuum to provide 54 g of [4-(1,1-dimethylethyl)amino-3-nitroquinolin-2-yl]trifluoromethanesulfonate.
Part B
Triethylamine (19.2 mL, 0.137 mole) was added to a solution of [4-(1,1-dimethylethyl)amino-3-nitroquinolin-2-yl]trifluoromethanesulfonate (54 g, 0.137 mole) in toluene (about 1 L). Dibenzylamine (27 mL, 0.137 mole) was added and the reaction mixture was heated at reflux for about 2 hours. The reaction mixture was concentrated under vacuum. The residue was diluted with methanol (900 mL). Hydrochloric acid (100 mL of 6N) was added and the reaction mixture was heated at reflux for 1 hour. The reaction mixture was stirred at ambient temperature overnight. The resulting precipitate was isolated by filtration, washed with methanol and then dried to provide 42.1 g of N 2 , N 2 -bis(phenylmethyl)-3-nitroquinoline-2,4-diamine hydrochloride as a yellow solid.
Part C
Sodium borohydride (5.5 g, 0.147 mmole) was carefully added to a solution containing nickel (II) chloride hydrate (11.9 g, 0.05 mole) in methanol (1200 mL). N 2 ,N 2 -bis(phenylmethyl)-3-nitroquinoline-2,4-diamine hydrochloride (42.1 g, 0.1 mole) was taken up in a mixture of methylene chloride (400 mL) and methanol (200 mL) and added to the nickel borate reagent. Additional sodium borohydride was carefully added until the generated foam was colorless. The reaction mixture was filtered through a layer of Celite™ filter agent. The filtrate was concentrated under vacuum. The residue was partitioned between methylene chloride and water. The methylene chloride layer was dried over magnesium sulfate then concentrated under vacuum. The residue was taken up in diethyl ether (about 1200 mL). Hydrochloric acid was bubbled through the ether solution for 5 minutes. The resulting precipitate was collected and dried to provide 32 g of N 2 ,N 2 -bis(phenylmethyl)quinoline-2,3,4-triamine hydrochloride.
Part D
Triethylamine (3.6 mL, 25.6 mmole) was added to a suspension of N 2 ,N 2 -bis(phenylmethyl)quinoline-2,3,4-triamine hydrochloride (5 g, 12.8 mmoles) in acetic acid (120 mL). Acetyl chloride (0.91 mL, 12.8 mmole) was added and the reaction mixture was heated at reflux for 5 to 6 hours then concentrated under vacuum. The residue was partitioned between diethyl ether and saturated aqueous sodium bicarbonate. The ether layer was dried then concentrated under vacuum. The residue was purified by column chromatography (silica gel eluting with methylene chloride containing 1-5% v/v ethyl acetate) to provide about 2.4 g of N,N-bis(phenylmethyl)-2-methyl-1H-imidazo[4,5-c]quinolin-4amine.
Part E
A suspension of sodium hydride (0.064 g, 2 mmole) in tetrahydrofuran (15 mL) was cooled in an ice bath. N,N-bis(phenylmethyl)-2-methyl-1H-imidazo[4,5-c]quinolin-4-amine (0.5 g, 1.32 mmole) was added and the reaction mixture was allowed to warm to room temperature for 20 minutes. Chloromethyl ethyl ether was added and the reaction mixture was stirred for 30 minutes. The reaction mixture was diluted with diethyl ether, washed twice with water, dried over magnesium sulfate and then concentrated under vacuum. The residue was purified by column chromatography (silica gel eluting with methylene chloride) to provide 0.43 g of N,N-bis(phenylmethyl)-1-ethoxymethyl-2-methyl-1H-imidazo[4,5-c]quinolin-4-amine.
Part F
Under a nitrogen atmosphere, a solution of N,N-bis(phenylmethyl)-1-ethoxymethyl-2-methyl-1H-imidazo[4,5-c]quinolin-4-amine (1.12 g, 2.56 mmole) in tetrahydrofuran (20 mL) was cooled to -78° C. Butyllithium (1.03 mL of 2.5M in hexanes, 2.56 mmole) was added and the reaction mixture was stirred for 5 minutes. 1-Bromo-3-chloropropane (2.7 mL, 25 mmole) was added and the reaction mixture was allowed to warm to ambient temperature. When the reaction was complete, as indicated by thin layer chromatography (silica gel, 30% ethyl acetate in hexanes v/v), the reaction mixture was diluted with diethyl ether and water. The ether layer was separated, dried over magnesium sulfate and then concentrated under vacuum. The resulting residue was purified by column chromatography (silica gel eluting with 10-20% ethyl acetate in hexanes v/v) to provide 0.76 g of N,N-bis(phenylmethyl)-2-(4-chlorobutyl)-1-ethoxymethyl-1H-imidazo[4,5-c]quinolin-4-amine.
Part G
Methanol (several mL) was added to a suspension of N,N-bis(phenylmethyl)-2-(4-chlorobutyl)-1-ethoxymethyl-1H-imidazo[4,5-c]quinolin-4-amine (0.76 g, 1.5 mmole) in 3N hydrochloric acid (20 mL). The reaction mixture was heated on a stream bath for 4 hours then partitioned between methylene chloride and aqueous saturated sodium bicarbonate. The methylene chloride layer was separated, dried over magnesium sulfate and then concentrated under vacuum to provide 0.64 g of N,N-bis(phenylmethyl)-2-(4-chlorobutyl)-1H-imidazo[4,5-c]quinolin-4-amine.
Part H
Sodium iodide (1 g, 6 mmole) and potassium carbonate (0.8 g, 6 mmole) were added to a solution of N,N-bis(phenylmethyl)-2-(4-chlorobutyl)-1H-imidazo[4,5-c]quinolin-4-amine (0.55 g, 1.2 mmole) in acetone. The reaction mixture was heated at reflux for 4 hours, filtered, and then concentrated under vacuum. The residue was purified by flash chromatography (silica gel eluting with 10-15% ethyl acetate in hexanes v/v). Nuclear magnetic resonance spectroscopy indicated the possible presence of iodo intermediate; so the residue was taken up in acetone, combined with sodium iodide and potassium carbonate and heated at reflux over night. The reaction was worked up to provide 0.38 g of N,N-bis(phenylmethyl)-8,9,10,11 tetrahydropyrido-[1',2':1,2]imidazo[4,5-c]quinolin-4-amine.
Part I
Palladium hydroxide on carbon (0.35 g) was added to a solution of N,N-bis(phenylmethyl)-8,9,10,11 tetrahydropyrido[1',2':1,2]imidazo[4,5-c]quinolin-4-amine (0.38 g, 0.9 mmole) in formic acid (about 15 mL). The reaction mixture was heated at reflux for 3 days then diluted with methylene chloride and made basic (about pH 9) with 10% sodium hydroxide. The methylene chloride layer was separated, dried over magnesium sulfate and then concentrated under vacuum to provide a white solid. The material was purified by column chromatography (silica gel eluting with 4-10% methanol in methylene chloride v/v) to provide a solid. The solid was suspended in methylene chloride (20 mL) then isolated by filtration and dried to provide 70 mg of 8,9,10,11 tetrahydropyrido[1',2':1,2]imidazo[4,5-c]quinolin-4-amine as a solid, m.p. 275°-278° C. Calculated for C 14 H 14 N 4 +0.2 CH 2 Cl 2 : %C, 66.81; %H, 5.69; %N, 21.95; Found: %C, 67.06; %H, 5.60; %N, 22.18.
EXAMPLE 2
10-Methyl-8,9,10,11-tetrahydropyrido[1',2',:1,2]imidazo[4,5-c]quinolin-6-amine
Part A
A solution of N,N-bis(phenylmethyl)-1-ethoxymethyl-2-methyl-1H-imidazo[4,5-c]quinolin-4-amine (1.8 g, 4.12 mmole, Example 1 Part E) in tetrahydrofuran (40 mL) was cooled to -78° C. Butyllithium (1.7 mL of 2.5M in hexanes, 4.2 mmole) was added and the reaction mixture was stirred for 20 minutes. 1-Bromo-3-chloro-2-methylpropane (4.8 mL, 41 mmole) was added and the reaction mixture was allowed to warm to ambient temperature over a period of 1 hour. The reaction mixture was diluted with diethyl ether and water. The ether layer was separated, dried over magnesium sulfate and then concentrated under vacuum. The resulting residue was purified by flash chromatography (silica gel eluting with 5-20% ethyl acetate in hexanes v/v) to provide 0.65 g of N,N-bis(phenylmethyl)-2-(4-chloro-3-methylbutyl)-1-ethoxymethyl-1H-imidazo[4,5-c]quinolin-4-amine.
Part B
Hydrochloric acid (80 mL of 6N) was added to a suspension of N,N-bis(phenylmethyl)-2-(4-chloro-3-methylbutyl)-1-ethoxymethyl-1H-imidazo[4,5-c]quinolin-4-amine (0.64 g, 1.2 mmole) in methanol (40 mL). The reaction mixture was heated at reflux for 2 hours (All of the methanol was driven off during this period.), diluted with methylene chloride and then made basic with 10% sodium hydroxide. The methylene chloride layer was separated, dried over magnesium sulfate and then concentrated to provide about 0.5 g of N,N-bis(phenylmethyl)-2-(4-chloro-3-methylbutyl)-1H-imidazo[4,5-c]quinolin-4-amine.
Part C
A large excess (about 10 fold) of both sodium iodide and potassium carbonate were added to a solution of N,N-bis(phenylmethyl)-2-(4-chloro-3-methylbutyl)-1H-imidazo[4,5-c]quinolin-4-amine (about 0.5 g) in acetone (about 75 mL). The reaction mixture was heated at reflux overnight, diluted with additional acetone, filtered and then concentrated under vacuum. The residue was washed with methylene chloride to recover the product from salts then purified by column chromatography (silica gel eluting with 3% ethyl acetate in methylene chloride v/v) to provide 0.35 g of N,N-bis(phenylmethyl)-8,9,10,11 tetrahydro-10-methylpyrido[1',2':1,2]imidazo[4,5-c]quinolin-4-amine.
Part D
Palladium hydroxide on carbon (0.35 g) was added to a solution of N,N-bis(phenylmethyl)-8,9,10,11 tetrahydro-10-methylpyrido[1',2':1,2]imidazo[4,5-c]quinolin-4-amine (0.35 g, 0.809 mmole) in formic acid (about 15 mL). The reaction mixture was heated at reflux for 3 days, diluted with a mixture of methanol and water, and then filtered through Celite™ filter agent. The filtrate was concentrated under vacuum and then made basic with 10% sodium hydroxide. The resulting precipitate was isolated by filtration then purified by column chromatography (silica gel eluting with 2-5% methanol in methylene chloride v/v) to provide 0.1 g of 10-methyl-8,9,10,11-tetrahydropyrido[1',2',:1,2]imidazo[4,5-c]quinolin-6-amine as a solid, m.p. 279°-281° C. Calculated for C 15 H 16 N 4 : %C, 71.40; %H, 6.39; %N, 22.20; Found: %C, 71.10; %H, 6.46; %N, 22.25.
EXAMPLE 3
8H-9,10,11,12-Tetrahydrohexamethyleneimino[1',2':1,2 ]imidazo[4,5,-c]quinolin-6-amine Hydrate
Part A
A solution of N,N-bis(phenylmethyl)-1-ethoxymethyl-2-methyl-1H-imidazo[4,5-c]quinolin-4-amine (1.5 g, 3.43 mmole, Example 1 Part E) in tetrahydrofuran (30 mL) was cooled to -78° C. Butyllithium (1.4 mL of 2.5M in hexanes, 3.5 mmole) was added dropwise followed by the addition of 1-bromo-4-chlorobutane (4 mL, 34 mmole). The reaction mixture was allowed to warm to ambient temperature then it was quenched with diethyl ether and water. The ether layer was separated, dried over magnesium sulfate and then concentrated under vacuum. The resulting residue was purified by column chromatography (silica gel eluting with 10% ethyl acetate in hexanes v/v) to provide 1.5 g of N,N-bis(phenylmethyl)-2-(5-chloropentyl)-1-ethoxymethyl-1H-imidazo[4,5-c]quinolin-4-amine.
Part B
A suspension of N,N-bis(phenylmethyl)-2-(5-chloropentyl)-1-ethoxymethyl-1H-imidazo[4,5-c]quinolin-4-amine (1.5 g, 3 mmole) in 6N hydrochloric acid (100 mL) was heated at reflux for 1 hour. The reaction mixture was cooled, diluted with methylene chloride, made basic with 10% sodium hydroxide and then extracted with methylene chloride (400 mL total). The methylene chloride extracts were combined, dried over magnesium sulfate and then concentrated under vacuum to provide about 1.3 g of N,N-bis(phenylmethyl)-2-(5-chloropentyl)-1H-imidazo[4,5-c]quinolin-4-amine.
Part C
Using the method of Example 2 Part C, N,N-bis(phenylmethyl)-2-(5-chloropentyl)-1H-imidazo[4,5-c]quinolin-4-amine (1.3 g, 3 mmole) was cyclized to provide 1.1 g of N,N-bis(phenylmethyl)-8H-9,10,11,12-tetrahydrohexamethyleneimino[1',2':1,2]imidazo[4,5-c]quinolin-6-amine as a white solid.
Part D
Palladium hydroxide on carbon (1 g) was added to a solution of N,N-bis(phenylmethyl)-8H-9,10,11,12-tetrahydrohexamethyleneimino[1',2':1,2]imidazo[4,5-c]quinolin-6-amine (1 g, 2.3 mmole) in formic acid (about 30 mL). The reaction mixture was heated at reflux for 4 days, filtered, washed with methanol/methylene chloride and then concentrated under vacuum. The residue was partitioned between methylene chloride and 10% sodium hydroxide. The methylene chloride layer was separated, dried over magnesium sulfate and then concentrated under vacuum. The residue was purified by column chromatography (silica gel eluting with 3-10% methanol in methylene chloride v/v) to provide 0.4 g of 8H-9,10,11,12-tetrahydrohexamethyleneimino[1',2':1,2]imidazo[4,5-c]quinolin-6-amine hydrate as a white solid, m.p. 237°-240° C. Calculated for C 15 H 16 N 4 +1/3H 2 O: %C, 69.74; %H, 6.50; %N, 21.69; Found: %C, 69.74; %H, 6.27; %N, 21.37.
EXAMPLE 4
9,10-Dihydro-8H-pyrrolo[1',2':1,2]imidazo[4,5,-c]quinolin-4-amine Hydrate
Part A
A solution of N,N-bis(phenylmethyl)-1-ethoxymethyl-2-methyl-1H-imidazo[4,5-c]quinolin-4-amine (1.7 g, 3.9 mmole, Example 1 Part E) in tetrahydrofuran (50 mL) was cooled to -78° C. Butyllithium (1.6 mL of 2.5M in hexanes, 4.1 mmole) was added dropwise and the reaction mixture was stirred for 5 minutes. Ethylene oxide was run over the surface of the reaction mixture. After 10 minutes the reaction mixture was allowed to warm to ambient temperature. The ethylene oxide addition was stopped when the reaction temperature reached 0° C. The reaction was quenched with diethyl ether and water. The ether layer was separated, dried over magnesium sulfate and then concentrated under vacuum. The resulting residue was purified by column chromatography (silica gel eluting with 5-10% ethyl acetate in methylene chloride v/v) to provide 1.4 g of N,N-bis(phenylmethyl)-2-(3-hydroxypropyl)-1-ethoxymethyl-1H-imidazo[4,5-c]quinolin-4-amine.
Part B
Thionyl chloride (5 mL, 68 mmole) was added to N,N-bis(phenylmethyl)-2-(3-hydroxypropyl)-1-ethoxymethyl-1H-imidazo[4,5-c]quinolin-4-amine (1 g, 2.1 mmole) and the reaction mixture was stirred rapidly until thin layer chromatography (silica gel, 10% ethyl acetate in methylene chloride v/v) indicated that the reaction was complete. The reaction mixture was diluted with methylene chloride then neutralized with 10% sodium hydroxide and sodium bicarbonate. The methylene chloride layer was separated, dried over magnesium sulfate and then concentrated under vacuum. The residue was purified by column chromatography (silica gel eluting with 10-30% ethyl acetate in hexanes v/v) to provide 1 g of N,N-bis(phenylmethyl)-2-(3-chloropropyl)-1-ethoxymethyl-1H-imidazo[4,5-c]quinolin-4-amine.
Part C
A suspension of N,N-bis(phenylmethyl)-2-(3-chloropropyl)-1-ethoxymethyl-1H-imidazo[4,5-c]quinolin-4-amine (1 g, 2.0 mmole) in 6N hydrochloric acid (80 mL) was heated at reflux for 2 hours and then stirred at ambient temperature overnight. The reaction mixture was neutralized with 10% sodium hydroxide then extracted with methylene chloride. The extract was dried over magnesium sulfate then concentrated under vacuum to provide 0.8 g of N,N-bis(phenylmethyl)-2-(3-chloropropyl)-1H-imidazo[4,5-c]quinolin-4-amine.
Part D
Potassium carbonate (10X excess) and sodium iodide (5X excess) were added to a solution of N,N-bis(phenylmethyl)-2-(3-chloropropyl)-1H-imidazo[4,5-c]quinolin-4-amine (0.8 g, 1.8 mmole) in acetone. The reaction was heated at reflux for 2 hours, filtered and then concentrated under vacuum. The residue was partitioned between methylene chloride and water. The methylene chloride layer was separated, dried over magnesium sulfate and then concentrated under vacuum. The residue was purified by column chromatography (silica gel eluting with 10-30% ethyl acetate in hexanes v/v) to provide 0.25 g of N,N-bis(phenylmethyl)-9,10-dihydro-8H-pyrrolo[1',2':1,2]imidazo[4,5-c]quinolin-4-amine.
Part E
Palladium hydroxide on carbon (0.5 g) was added to a solution of N,N-bis(phenylmethyl)-9,10-dihydro-8H-pyrrolo[1',2':1,2]imidazo[4,5-c]quinolin-4-amine (0.25 g, 0.62 mmole) in formic acid (75 mL). The reaction mixture was heated at reflux for 4 days then diluted with methanol and filtered. The filtrate was concentrated under vacuum then mixed with water and sodium bicarbonate. A gray precipitate was isolated by filtration. The filtrate was concentrated. The resulting residue was slurried with a mixture of methanol and methylene chloride and then filtered. The filtrate was combined with the previously isolated gray precipitate then purified by column chromatography (silica gel eluting with 3-5% methanol in methylene chloride v/v) to provide 80 mg of N,N- bis(phenylmethyl)-9,10-dihydro-8H-pyrrolo[1',2':1,2]imidazo[4,5-c]quinolin-4-amine as a white solid, m.p. 275°-277° C. Analysis: Calculated for C 13 H 12 N 4 +1/3H 2 O: %C, 67.81; %H, 5.54; %N, 24.33; Found: C, 67.80; %H, 5.26; %N, 24.28.
EXAMPLE 5
10,11-Dihydro-8H-[1,4]-oxazino[4',3':1,2]imidazo[4,5-c]quinolin-6-amine
Part A
A suspension of N 2 ,N 2 -bis(phenylmethyl)quinoline-2,3,4-triamine hydrochloride (10 g, 25.6 mmole, Example 1 Part C) in triethyl orthoformate (40 mL) was heated at about 120° C. for 30 minutes, cooled to ambient temperature and then diluted with diethyl ether. The resulting precipitate was isolated by filtration then partitioned between ammonium hydroxide and methylene chloride. The methylene chloride layer was separated, washed twice with water, dried over magnesium sulfate and then concentrated under vacuum to provide 8.6 g of N,N-bis(phenylmethyl)-1H-imidazo[4,5-c]quinolin-4-amine as a dark brown solid.
Part B
A solution of N,N-bis(phenylmethyl)-1H-imidazo[4,5-c]quinolin-4-amine (2 g, 5.49 mmole) in tetrahydrofuran (10 mL) was added to a suspension of sodium hydride (0.21 g, 6.58 mmole) in tetrahydrofuran (25 mL). After 30 minutes chloromethyl ethyl ether (0.61 mL, 6.58 mmole) was added and the reaction mixture was stirred for 2 hours. The reaction mixture was diluted with diethyl ether, washed with water, dried over magnesium sulfate, and then concentrated under vacuum to provide crude product as a brown oil. The oil was purified by column chromatography (silica gel eluting with 20-30% ethyl acetate in hexanes v/v) to provide 1.77 g of N,N-bis(phenylmethyl)-1-ethoxymethyl-1H-imidazo[4,5-c]quinolin-4-amine as a white/tan solid.
Part C
Butyllithium (1.6 mL of 2.5M in hexanes, 4 mmole) was added to a chilled (dry ice/acetone bath) solution of N,N-bis(phenylmethyl)-1-ethoxymethyl-1H-imidazo[4,5-c]quinolin-4-amine (1.7 g, 4 mmole) in tetrahydrofuran. No color change was observed. The reaction mixture was warmed to -20° C. (dry ice/carbon tetrachloride) and the reaction turned red in color. Formaldehyde gas entrained in a flow of nitrogen was added to the reaction mixture. After several minutes the reaction turned to a solid mass and the ice bath was removed. The reaction mixture was allowed to warm to ambient temperature and the color of the reaction mixture changed from red to yellow. The reaction was diluted with diethyl ether and water. The ether layer was separated, dried over magnesium sulfate and then concentrated under vacuum. The residue was purified by column chromatography (silica gel eluting with 10-20% ethyl acetate in hexanes v/v) to provide 1 g of 4-bis(phenylmethyl)amino-1-ethoxymethyl-1H-imidazo[4,5-c]quinolin-2-methanol.
Part D
Sodium hydride (0.11 g, 3.3 mmole) was added to a solution of 4-bis(phenylmethyl)amino-1-ethoxymethyl-1H-imidazo[4,5-c]quinolin-2-methanol (1 g, 2.21 mmole) in N,N-dimethylformamide (15 mL) and the resulting mixture was stirred for 10 minutes. 1-Bromo-2-(trityloxy)ethane was added and stirring was continued at ambient temperature for 3-4 hours. The reaction was quenched with diethyl ether and water. The ether layer was separated, washed several times with water, dried over magnesium sulfate and then concentrated under vacuum. The residue was purified by column chromatography (silica gel eluting with 10-30% ethyl acetate in hexanes v/v) to provide 1.1 g of N,N-bis(phenylmethyl)-1-ethoxymethyl-2-[(2-triphenylmethoxy)ethoxy]methyl-1H-imidazo[4,5-c]quinolin-4-amine.
Part E
A suspension of N,N-bis(phenylmethyl)-1-ethoxymethyl-2-[(2-triphenylmethoxy)ethoxy]methyl-1H-imidazo[4,5-c]quinolin-4-amine (1.1 g, 1.5 mmole) in 6N hydrochloric acid (25 mL) was heated on a steam bath for 1.5 hours. The reaction mixture was neutralized to pH 7 then extracted with methylene chloride. The extract was dried then concentrated under vacuum. The residue was purified by column chromatography (silica gel eluting with 10-50% ethyl acetate in hexanes v/v) to provide 0.5 g of N,N-bis(phenylmethyl)-2-(2-hydroxyethoxy)methyl-1H-imidazo[4,5-c]quinolin-4-amine.
Part F
Triethylamine (0.17 mL, 1.25 mmole) was added to a solution of N,N-bis(phenylmethyl)-2-(2-hydroxyethoxy)methyl-1H-imidazo[4,5-c]quinolin-4-amine (0.5 g, 1.14 mmole) in methylene chloride (20 mL). Methanesulfonyl chloride (0.09 mL, 1.14 mmole) was added and the reaction mixture was stirred at ambient temperature for 1 hour. The reaction mixture was diluted with methylene chloride, washed with water, dried over magnesium sulfate and then concentrated under vacuum to provide 0.6 g of N,N-bis(phenylmethyl)-2-(2-methylsulfonyloxyethoxy)methyl-1H-imidazo[4,5-c]quinolin-4-amine.
Part G
Excess potassium carbonate and excess sodium iodide were added to a solution of N,N-bis(phenylmethyl)-2-(2-methylsulfonyloxyethoxy)methyl-1H-imidazo[4,5-c]quinolin-4-amine (0.6 g, 1.14 mmole) in acetone (200 mL). The reaction mixture was heated at reflux overnight then concentrated under vacuum. The residue was partitioned between methylene chloride (150 mL) and water (50 mL). The methylene chloride was separated, dried over magnesium sulfate and then concentrated under vacuum. The residue was purified by column chromatography (silica gel eluting with 10:10:80 v/v/v methylene chloride:ethyl acetate:hexanes) to provide 0.42 g of N,N-bis(phenylmethyl)-10,11-dihydro-8H-[1,4]-oxazino[4',3':1,2]imidazo[4,5-c]quinolin-6amine as a white solid.
Part H
Palladium hydroxide on carbon (0.5 g) was added to a solution of N,N-bis(phenylmethyl)-10,11-dihydro-8H-[1,4]-oxazino[4',3':1,2]imidazo[4,5-c]quinolin-6-amine (0.4 g, 0.95 mmole) in formic acid (about 40 mL). The reaction mixture was heated at reflux for 6 days then diluted with methanol and filtered through a layer of Celite™ filter agent. The filtrate was made basic with ammonium hydroxide then concentrated under vacuum. The residue was taken up in a mixture of methanol and methylene chloride. Silica gel was added and the resulting mixture was concentrated under vacuum. The solid was placed on a column and eluted with 2-5% methanol in methylene chloride to provide a white solid. The nuclear magnetic resonance spectra was consistent with the formate salt of the desired product. The salt was taken up in 5% hydrochloric acid and heated on a steam bath for 30 minutes. The mixture was made basic with 10% sodium hydroxide. The resulting precipitate was isolated by filtration, washed with water and dried under vacuum to provide 75 mg of 10,11-dihydro-8H-[1,4]-oxazino[4',3':1,2]imidazo[4,5-c]quinolin-6-amine as a solid, m.p. 258°-259° C. Analysis: Calculated for C 13 H 12 N 4 O: %C, 64.99; %H, 5.03; %N, 23.32; Found: %C, 64.61; %H, 4.88; %N, 23.18.
INTERFERON (α) INDUCTION IN HUMAN CELLS
An in vitro human blood cell system was used to assess interferon induction by compounds of the invention. Activity is based on the measurement of interferon secreted into culture media. Interferon is measured by bioassay.
Blood Cell Preparation for Culture
Whole blood is collected by venipuncture into EDTA vacutainer tubes. Peripheral blood mononuclear cells (PBM's) are separated from whole blood by using either LeucoPREP™ Brand Cell Separation Tubes (available from Becton Dickinson) or Ficoll-Paque® solution (available from Pharmacia LKB Biotechnology Inc, Piscataway, N.J.). The PBM's are suspended at 1×10 6 /mL in RPMI 1640 media (available from GIBCO, Grand Island, N.Y.) containing 25 mM HEPES (N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid) and L-glutamine (1% penicillin-streptomycin solution added) with 10% heat inactivated (56° C. for 30 minutes) autologous serum added. 200 μL portions of PBM suspension are added to 96 well (flat bottom) MicroTest III sterile tissue culture plates.
Compound Preparation
The compounds are solubilized in ethanol, dimethyl sulfoxide or tissue culture water then diluted with tissue culture water, 0.01N sodium hydroxide or 0.01N hydrochloric acid (The choice of solvent will depend on the chemical characteristics of the compound being tested.). Ethanol or DMSO concentration should not exceed a final concentration of 1% for addition to the culture wells. Compounds are initially tested in a concentration range of from about 0.1 μg/mL to about 5 μg/mL. Compounds which show induction at a concentration of 0.5 μg/mL are then tested in a wider concentration range.
Incubation
The solution of test compound is added in a volume (less than or equal to 50 μL) to the wells containing 200 μL of diluted whole blood or of PBM's in media. Solvent and/or media is added to control wells (wells with no test compound) and as needed to adjust the final volume of each well to 250 μL. The plates are covered with plastic lids, vortexed gently and then incubated for 48 hours at 37° C. with a 5% carbon dioxide atmosphere.
Separation
Following incubation, the plates are covered with parafilm and then centrifuged at 1000 rpm for 10 to 15 minutes at 4° C. in a Damon IEC Model CRU-5000 centrifuge. Media (about 200 μL) is removed from 4 to 8 wells and pooled into 2 mL sterile freezing vials. Samples are maintained at -70° C. until analysis.
Interferon Analysis/Calculation
Interferon is determined by bioassay using A549 human lung carcinoma cells challenged with encephalomyocarditis. The details of the bioassay method have been described by G. L. Brennan and L. H. Kronenberg in "Automated Bioassay of Interferons in Micro-test Plates", Biotechniques, June/July, 78, 1983, incorporated herein by reference. Briefly stated the method is as follows: interferon dilutions and A549 cells are incubated at 37° C. for 12 to 24 hours. The incubated cells are infected with an inoculum of encephalomyocarditis virus. The infected cells are incubated for an additional period at 37° C. before quantifying for viral cytopathic effect. The viral cytopathic effect is quantified by staining followed by spectrophotometric absorbance measurements. Results are expressed as alpha reference units/mL based on the value obtained for NIH HU IF-L standard. The interferon was identified as essentially all interferon alpha by testing in checkerboard neutralization assays against rabbit anti-human interferon (beta) and goat anti-human interferon (alpha) using A549 cell monolayers challenged with encephalomyocarditis virus. Results are shown in the table below wherein the absence of an entry indicates that the compound was not tested at that particular dose concentration.
______________________________________Interferon (α) Induction in Human CellsCompound α Reference Units/mLof Dose Concentration (μg/mL)Example 0.01 0.05 0.10 0.50 1.0 5.0______________________________________1 2 5 320 1000 370 462 -- -- 4 50 66 73 -- -- 4 100 130 324 5 510 1200 160 190 3805 1 1 510 310 170 210______________________________________
INTERFERON INDUCTION IN MICE
This test method was used to assess the ability of compounds of the invention to induce interferon biosynthesis in mice.
For each dose level being tested, three groups (three mice per group) of male mice (nonfasted) are dosed orally with compound. One hour later blood is collected from the retrobulbar plexus and pooled. The blood is centrifuged and serum collected and aliquoted. The serum samples are stored frozen at -70° C. until analysis. This procedure is repeated at 2 hours post dose with the second group of mice and at four hours post dose with the third group of mice.
Samples are assayed as described above in connection with the analysis of interferon induction in human cells. The results are expressed in the table below as α/β reference units/mL based on the value obtained for a mouse MU-1-IF standard. Results are shown in the table below wherein results designated "<" a certain number indicate that interferon was not detectable in amounts above the lower sensitivity level of the assay.
______________________________________Interferon Induction in MiceCompound Dose Reference Units/mLof Example (mg/Kg) 1 hr 2 hr 4 hr______________________________________1 0.3 <250 <250 <2501 1.0 480 480 <2501 3.0 480 1300 3301 10.0 1600 4300 4803 0.3 <380 <380 <3803 1.0 <380 <380 <3803 3.0 1100 820 <3803 10.0 1500 2900 6604 0.3 <520 520 <5204 1.0 1100 1100 <5204 3.0 2700 3500 <5204 10.0 4700 11000 <5205 0.3 <310 <310 <3105 1.0 310 <310 <3105 3.0 1100 1200 3105 10.0 1700 2100 630______________________________________
INDIRECT IN-VITRO ANTIVIRAL ACTIVITY
The test method described below demonstrates the ability of compounds of the invention to inhibit the progress of viral infection.
Whole blood is collected by venipuncture into EDTA vacutainer tubes. Peripheral blood mononuclear cells (PBM's) are isolated using Ficoll-Paque® solution (available from Pharmacia LKB Biotechnology Inc., Piscataway, N.J.). The PBM's are washed with phosphate buffer saline then diluted with RPMI 1640 medium (available from GIBCO, Grand Island, N.Y.) and 10% fetal bovine serum to obtain a final concentration of 2.5×10 6 cells/mL. One mL portions of PBM's in medium are placed in 15 mL polypropylene tubes. The test compound is dissolved in dimethyl sulfoxide then diluted with RPMI 1640 medium. The solution of test compound is added to the tubes containing the PBM's to give final concentrations ranging from 0.05 μg/mL to 1.0 μg/mL. Control tubes do not receive any test compound. The tubes are then incubated for 24 hours at 37° C. with a 5% carbon dioxide atmosphere. Following incubation the tubes are centrifuged at 400 xg for 5 minutes. The supernatant is removed. The PBM's are brought up in 100 μL of RPMI 1640 medium and then infected with a 100 μL containing 10 5 tissue culture 50% infectious doses of vesicular stomatitis virus (VSV). The tubes are incubated for 30 minutes at 37° C. to allow virus adsorption. One mL of RPMI 1640 medium is added to each tube and the tubes are incubated for 48 hours at 37° C. The tubes are frozen then thawed to lyse the cells. The tubes are centrifuged at 400 xg for 5 minutes to remove cellular debris then the supernatant is assayed by serial tenfold dilutions on Vero cells in 96 well microtiter plates. The infected cells are incubated for 24 hours at 37° C. before quantifying for viral cytopathic effect. The viral cytopathic effect is quantified by staining with 0.05% crystal violet. Results are presented as VSV inhibition, defined as the log 10 (control VSV yield/experimental VSV yield). Results are shown in the table below wherein the absence of an entry indicates that the compound was not tested at that particular concentration. Control tubes have a value of 0.
______________________________________In-vitro Antiviral ActivityCompound VSV Yield Inhibitionof Dose Concentration (μg/mL)Example 0.05 0.1 0.5 1.0______________________________________1 8.0 8.0 8.0 --2 -- 2.0 4.0 5.0______________________________________ | Compounds and pharmaceutically acceptable salts thereof formally derived by bridging the 1- and 2-positions of 1H-imidazo[4,5-c]quinolin-4-amines. Also, methods of using such compounds and pharmaceutical formulations containing such compounds. Said compounds are useful to induce interferon biosynthesis in an animal. | 2 |
BACKGROUND
[0001] 1. Field
[0002] The present invention relates to grips for hand railings or other hand support systems. More specifically, the present invention relates to grips which are releasably adhered to railings or other hand support systems.
[0003] 2. Prior Art
[0004] Hand railings are in use throughout the world to assist in human activity such as standing, sitting down, ascending and descending a stairway, entering or exiting a moving vehicle, walking, etc. Maintaining a secure, comfortable grip is extremely important when operating or using various hand-held apparatuses or, more importantly, simply for safety purposes when grasping any type of railing. Bare railings are used for hand supports by users, standing, or sitting, or while entering or exiting a vehicle. Bare railings, whether they are constructed from any type of metal, plastic, wood, glass, concrete or composite material can be slippery, or coarse and inconvenient to hold onto with bare hands. Furthermore, uncovered railings located in moving vehicles such as subway train cars, light rail transit cars, transit buses, trams, street cars, trolley cars, recreational vehicles, etc., are unsafe when the vehicle is in motion and especially when turning. Typically, such railings are extruded shapes, such as a circular tube or another similar shape made for the human hand to grasp. Additionally, these railings are usually constructed from durable metal, such as stainless steel, but may also be constructed from wood or various other substances.
[0005] Such typical hand railings, however, do not provide a positive gripping surface, which would still further assist in the corresponding human activity associated with the hand railing. Some of the present gripping devices include molded plastic cylindrical grips which are installed and include cross-sectional sections designed to fit the human hand as in U.S. Pat. No. 5,584,096 to Auroura, rigid hand railings having a plurality of finger sized indentations, U.S. Pat. No. 5,190,267 to Schmitt, et al. and rail covering systems for outdoor decks as in U.S. Pat. No. 6,062,519 to Baldassarre. Still other gripping devices include removable foam grips that are wrapped around a bar each time a user wishes to use a bar as in U.S. Pat. No. 5,775,756 to Rozenich. This type of grip is typically used for weightlifting equipment. The grips to date involve either railings with built in grips or grips that are, for the most part, permanently attached to the railings, while other grips are not attached at all, rather they are easily removed and transferred from bar to bar.
[0006] To date, no grips have been designed which will conform to any railing surface or shape and which are releasably attachable to such railing surface. Hence, there is a need for a grip which will conform to any railing type and which will attach to any railing surface regardless of the type of surface or type of material used as the grip and a grip which is releasably attachable to the railing.
SUMMARY OF THE INVENTION
[0007] The present invention is a method, system and device for providing a secure, resilient gripping surface on a railing or other hand support system. The grip of the present invention is designed to provide a secure, resilient gripping surface on any railing or hand support system surface that is grasped by a hand. The grip is preferably utilized on a railing or other hand support system. However, it is readily apparent that the grip could also be used on other structures, such as support poles and beams, etc.
[0008] In one aspect of the present invention, a flexible gripping pad is provided which is easily secured to a railing or hand support system by wrapping the grip around the railing or hand support system. The grip may fully cover the railing, or it may be artfully wrapped or it may be partially or fully folded. The grip of this invention will provide a comfortable, resilient gripping surface which will enhance the safety of a railing or hand support system by preventing slipping, hand abrasions or other dangers associated with railings or hand support systems.
[0009] In one aspect, the grip of the present invention comprises a skin layer having a top surface and a bottom surface, and a 4-way stretchable material layer having a top surface and a bottom surface. The top surface of the 4-way stretchable material layer is permanently adhered to the bottom surface of the skin layer. The bottom surface of the 4-way stretchable material layer is releasably attached to the railing or hand support system.
[0010] The skin layer may be formed from any material which will provide a safe and secure gripping surface. Some examples of possible skin materials include expanded vinyl, which is vinyl with a layer of foam that imparts a soft, textured feel, leather, plastic sheeting, plastic roll stock, any type of foam product, polyurethane, urethane, woven fabrics, rubber material and foil material. If a vinyl material is used, the vinyl may be supported or unsupported. Similarly, the 4-way stretchable material may comprise any material that can be simultaneously stretched in four directions, such as mylar.
[0011] In yet another aspect of the present invention, the skin layer of the grip of the present invention has a luminescent quality. The luminescent skin layer glows in the dark to provide additional safety in cases of an emergency.
[0012] In another embodiment, the grip of the present invention comprises a skin layer having a top surface and a bottom surface, and a backing layer having a top surface and a bottom surface. The top surface of the backing layer is permanently adhered to the bottom surface of the skin layer. Furthermore, the backing layer is permanently attached to a 4 way stretchable material layer with a stretchable top surface and a stretchable bottom surface. The bottom surface of the 4-way stretchable material layer is releasably attached to the railing or hand support system.
[0013] The grip of the present invention may have tapered edges on its lengthwise sides so that when the grip is spirally wrapped around a railing or other hand support system and the edges overlap, the thickness of the grip remains constant. As an alternative to wrapping the grip such that the edges overlap, the grip may be wrapped so that the edges do not overlap, thus providing additional friction for the user.
[0014] One method of manufacturing the grip of the present invention comprises providing a skin layer which has a top surface for gripping and a bottom surface to which a permanent adhesive applied. Next, a 4-way stretchable material that has a top surface and a bottom surface is permanently attached to the bottom surface of the skin layer. Finally, the bottom surface of the 4-way stretchable material is releasably adhered to the railing.
[0015] Another method of manufacturing the grip of the present invention comprises providing a skin layer which has a top surface for gripping and a bottom surface to which a permanent adhesive is applied. Next, a backing layer is provided, which has a top surface and a bottom surface. The top surface of the backing layer is adhered to the bottom surface of the skin layer. Next, a 4-way stretchable material layer with a top surface and a bottom surface is permanently attached to the backing layer by adhering the backing layer bottom surface to the 4-way stretchable layer top surface. Finally, the 4-way stretchable material is releasably adhered to the railing.
[0016] The system of the present invention is designed for providing a secure, safe, releasably attachable grip on a railing. The system comprises a grip having a 4-way stretchable layer with an inner surface and an outer surface and a skin layer with an inner surface and an outer surface, the inner surface of the skin layer is adhered to the outer surface of the 4-way stretchable layer. The inner surface of the 4-way stretchable layer is releasably adhered to the railing.
[0017] Another system of the present invention is also designed for providing a secure, safe, releasably attachable grip on a railing. The system comprises a grip having a backing layer with an inner surface and an outer surface and a skin layer with an inner surface and an outer surface, the inner surface of the skin layer is adhered to the outer surface of the backing layer. The bottom surface of the backing layer is permanently adhered to a 4-way stretchable layer with an inner surface and an outer surface. The inner surface of the 4-way stretchable layer is releasably adhered to the railing.
[0018] As set forth above, the grip of the present invention may have tapered edges on its lengthwise sides so that when the grip is wrapped around a railing or other hand support system and the edges overlap, the thickness of the grip remains constant. As an alternative to wrapping the grip such that the edges overlap, the grip may be wrapped so that the edges do not overlap, thus providing additional friction for the user.
[0019] One method of placing the grip of the present invention on the railing comprises providing a railing and wrapping the tapered edge grip of the present invention spirally around the railing such that the tapered edges of the grip overlap. The length of the railing may be fully covered by the grip such that the thickness of the grip remains constant or, in the alternative, the edges may not overlap to provide additional friction for the user.
[0020] Another method of placing the grip of the present invention on a railing comprises providing a railing having a length and alignment targets in a parallel line along its length. Next, placing the grip so that the center lengthwise axis of the grip is centered on the axis parallel to the length of the railing. The grip of the present invention has alignment targets disposed along an axis parallel to the lengthwise edge of the grip and the grip folds around the railing such that the alignment targets of the grip align with the alignment targets of the railing and the edges of the grip abut when folded around the railing.
[0021] The grip of this invention will provide a positive gripping surface for any type of railing using any type of material as a grip and provide a safe, uniform gripping surface for the length of the railing's surface. Moreover, there is a need for a method of manufacturing for grips and a system for providing grips which are releasably adhered to a railing or hand support system. Finally, there is a need for a method of placing the grip of the present invention on to a railing or other hand support system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] [0022]FIG. 1 is a side view of an embodiment of the grip.
[0023] [0023]FIG. 2 is perspective view of the grip of FIG. 1.
[0024] [0024]FIG. 3 is a cross-sectional view of the grip if FIG. 2 taken along the line A-A.
[0025] [0025]FIG. 4 is a side view of another embodiment of the grip.
[0026] [0026]FIG. 5 is perspective view of the grip of FIG. 4.
[0027] [0027]FIG. 6 is a cross-sectional view of the grip if FIG. 4 taken along the line A-A.
[0028] [0028]FIGS. 7 a - 7 c show a method or procedure for manufacture of the grip of FIG. 1.
[0029] [0029]FIGS. 8 a - 8 e show a method or procedure for manufacture of the grip of FIG. 4.
[0030] [0030]FIG. 9 shows a method of wrapping the grip of FIG. 1.
[0031] [0031]FIG. 10 shows a method of wrapping the grip of FIG. 4.
[0032] [0032]FIG. 11 shows a method of spirally wrapping the grip of FIG. 1 or FIG. 4.
DETAILED DESCRIPTION
[0033] [0033]FIG. 1 discloses grip 100 for use on a railing or hand support system. Grip 100 has a skin layer 104 and a 4-way stretchable layer 112 . Skin layer 104 has a top surface 102 which provides a comfortable, secure and safe gripping surface. Skin layer 104 can be formed from a variety of materials. Examples of such materials include expanded vinyl, which is vinyl with a layer of foam that imparts a soft, textured feel, leather, plastic sheeting, plastic roll stock, any type of foam product, polyurethane, urethane, woven fabrics, rubber material, foil material or any other material which could act as a covering to a hand support system. If skin layer 104 is formed from expanded vinyl, the vinyl surface may be smooth or textured. In addition, if a vinyl material is used, the vinyl may be supported or unsupported. In yet another aspect of the present invention, skin layer 104 of grip 100 of the present invention has a luminescent quality. The luminescent skin layer glows in the dark to provide additional safety in cases of an emergency. Any methods known in the art for creating luminescence may be used, for example some of the methods include transfer application processes, wet ink processes and sublimation ink processes.
[0034] Skin layer 104 has a bottom surface 106 which is affixed to the top surface 110 of 4-way stretchable material layer 112 by a permanent adhesive 108 that completely covers skin layer 104 from edge to edge. The permanent adhesive 108 can be any permanent adhesive known in the art which will permanently bond skin layer 104 to 4-way stretchable material layer 112 . An example of such a permanent adhesive is Flexicon® adhesive V-402. However, it will be clear to one skilled in the art that other similar suitable adhesives may be used.
[0035] 4-way stretchable layer 112 has top surface 110 and a bottom surface 114 , such that top surface 110 of 4-way stretchable layer 112 conforms to and is permanently affixed to bottom surface 106 of skin layer 104 . 4-way stretchable layer 112 may be comprised of any material that can simultaneously stretch in four directions such as mylar. Bottom surface 114 of 4-way stretchable layer 112 is releasably attached to the railing or hand support system by a layer of releasable adhesive 116 . Releasable adhesive 116 completely covers from edge to edge and is affixed to 4-way stretchable layer 112 and provides releasable adhesion to the railing or hand support system. Releasable adhesive 116 provides secure adhesion to the railing or hand support system but may be removed with a minimal amount of effort by peeling grip 100 off the railing or hand support system. An example of a releasable adhesive is Flexicon® V-58.
[0036] In one embodiment of grip 100 disclosed in FIG. 3, the lengthwise edges of skin layer 104 and 4-way stretchable layer 112 may be tapered in thickness. FIG. 2 discloses a top view of grip 100 . FIG. 3 discloses a cross sectional view of grip 100 taken from cross sectional line A to A of FIG. 2. Tapering the edges of skin layer 104 and 4-way stretchable layer 112 allows for the edges to overlap when wrapping a railing or hand support system and at the same time to maintain a constant thickness of grip 100 despite the overlapping edges. In another embodiment, the edges are tapered but wrapped in such a way that they do not overlap to provide still more friction for the user. In still another embodiment, the lengthwise edges of skin layer 104 and 4-way stretchable layer 112 are not tapered for instances when the edges do not overlap.
[0037] [0037]FIG. 4 discloses another embodiment of the present invention. Grip 200 has a skin layer 204 , a backing layer 212 and a 4-way stretchable layer 220 . Skin layer 204 has a top surface 202 which provides a comfortable, secure and safe gripping surface. Skin layer 204 can be formed from a variety of materials. Examples of such materials include, but are not limited to, expanded vinyl, which is vinyl with a layer of foam that imparts a soft, textured feel, leather, plastic sheeting, plastic roll stock, any type of foam product, polyurethane, urethane, woven fabrics, rubber material, foil material or any other material which could act as a covering to a hand support system. If skin layer 204 is formed from expanded vinyl, the vinyl surface may be smooth or textured. In addition, if a vinyl material is used, the vinyl may be supported or unsupported. In yet another aspect of the present invention, skin layer 204 of grip 200 of the present invention has a luminescent quality. The luminescent skin layer glows in the dark to provide additional safety in cases of an emergency. Any methods known in the art for creating luminescence may be used, for example some of the methods include transfer application processes, wet ink processes and sublimation ink processes.
[0038] Skin layer 204 has a bottom surface 206 which is affixed to top surface 210 of backing layer 212 by a permanent adhesive 208 which completely covers bottom surface 214 backing layer 212 from edge to edge. The permanent adhesive 208 can be any permanent adhesive known in the art which will permanently bond skin layer 204 to backing layer 212 . An example of such a permanent adhesive is Flexicon® adhesive V-402. However, it will be clear to one skilled in the art that other similar suitable adhesives may be used.
[0039] Backing layer 212 has a top surface 210 and a bottom surface 214 , such that top surface 210 of backing layer 212 conforms to and is affixed to bottom surface 206 of skin layer 204 . Backing layer 212 may be comprised of any material suitable for providing support including open cell foam, closed cell foam, felt, paper or rubber. Bottom surface 214 of backing layer 212 is permanently adhered to the top surface 218 of 4-way stretchable material 220 . The permanent adhesive attaching bottom surface 214 of backing layer 212 to top surface 218 of 4-way stretchable material 220 can be any permanent adhesive known in the art which will permanently bond the surfaces an example of which is Flexicon® V-402. 4-way stretchable material 220 has the ability to stretch in all directions simultaneously. An example of a 4-way stretchable material is Mylar. Bottom surface 222 of 4-way stretchable layer 220 is releasably attached to the railing or hand support system by releasable adhesive 224 . Releasable adhesive 224 is affixed to and completely covers 4-way stretchable material 220 from edge to edge and provides releasable adhesion to the railing or hand support system. Releasable adhesive 224 provides secure adhesion to the railing or hand support system but may be removed with a minimal amount of effort by peeling grip 200 off the railing or hand support system. An example of a releasable adhesive is Flexicon® V-58.
[0040] In one embodiment of grip 200 disclosed in FIG. 4, the lengthwise edges of skin layer 204 , backing layer 212 and 4-way stretchable layer 220 may be tapered in thickness. FIG. 5 discloses a top view of grip 200 . FIG. 6 discloses a cross sectional view of grip 200 taken from cross sectional line A to A of FIG. 5. Tapering the edges of skin layer 204 , backing layer 212 and 4-way stretchable layer 220 allows for the edges to overlap when wrapping a railing or hand support system and at the same time to maintain a constant thickness of grip 200 despite the overlapping edges. In another embodiment, the edges are tapered but wrapped in such a way that they do not overlap to provide still more friction for the user. In still another embodiment, the lengthwise edges of skin layer 204 , backing layer 212 and 4-way stretchable layer 220 are not tapered for instances when the edges do not overlap but a consistent thickness of grip is desired.
[0041] [0041]FIGS. 7 a - 7 c disclose a method or procedure for manufacture of grip 100 . For convenience, the component parts of grip 100 are numbered as in FIG. 1 designating grip 100 . The method or procedure for manufacture of grip 100 begins with the act 7 a of providing a skin layer 104 and applying permanent adhesive 108 to skin layer 104 . Skin layer 104 can be formed from a variety of materials. Examples of such materials include expanded vinyl, which is vinyl with a layer of foam that imparts a soft, textured feel, leather, plastic sheeting, plastic roll stock, any type of foam product, polyurethane, urethane, woven fabrics, rubber material, foil material or any other material which could act as a covering to a hand support system. If skin layer 104 is formed from expanded vinyl, the vinyl surface may be smooth or rough. In addition, if a vinyl material is used, the vinyl may be supported or unsupported. Next 4-way stretchable material layer 112 is permanently adhered to skin layer 104 as disclosed in FIG. 7 b. As previously set forth, 4-way stretchable layer 112 may be comprised of any material that can simultaneously stretch in four directions such as mylar. Then a releasable adhesive 116 is applied from edge to edge to 4-way stretchable material layer 112 .
[0042] In one embodiment of the method of manufacture of grip 100 disclosed in FIG. 3, the lengthwise edges of skin layer 104 and 4-way stretchable layer 112 may be tapered in thickness. FIG. 2 discloses a top view of grip 100 . FIG. 3 discloses a cross sectional view of grip 100 taken from cross sectional line A to A of FIG. 2. Tapering the edges of skin layer 104 and 4-way stretchable layer 112 allows for the edges to overlap when wrapping a railing or hand support system and at the same time to maintain a constant thickness of grip 100 despite the overlapping edges. In another embodiment, the edges are tapered but wrapped in such a way that they do not overlap to provide still more friction for the user. In still another embodiment, the lengthwise edges of skin layer 104 and 4-way stretchable layer 112 are not tapered for instances when the edges do not overlap.
[0043] [0043]FIGS. 8 a - 8 e discloses a method or procedure for manufacture of grip 200 . For convenience, the component parts of grip 200 are numbered as in FIG. 4 designating grip 200 . The method or procedure for manufacture of grip 200 begins with the act 8 a of providing a skin layer 204 and applying permanent adhesive 208 from edge to edge of skin layer 204 . Skin layer 204 can be formed from a variety of materials. Examples of such materials include, but are not limited to, expanded vinyl, which is vinyl with a layer of foam that imparts a soft, textured feel, leather, plastic sheeting, plastic roll stock, any type of foam product, polyurethane, urethane, woven fabrics, rubber material, foil material or any other material which could act as a covering to a hand support system. If skin layer 204 is formed from expanded vinyl, the vinyl surface may be smooth or rough. In addition, if a vinyl material is used, the vinyl may be supported or unsupported. Next backing layer 212 is permanently adhered to skin layer 204 as disclosed in FIG. 8 b. As previously set forth, backing layer 212 may be comprised of any material suitable for providing support including open cell foam, closed cell foam, felt, paper or rubber. Next, as disclosed in FIG. 8 c, permanent adhesive 216 is applied to backing layer 212 . Then, as shown in FIG. 8 d, 4-way stretchable layer 220 is adhered to backing layer 212 . Finally, as disclosed in FIG. 8 e, a releasable adhesive 224 is applied from edge to edge to 4-way stretchable layer 220 .
[0044] In one embodiment of the method of manufacture of grip 200 disclosed in FIG. 4, the lengthwise edges of skin layer 204 , backing layer 212 and 4-way stretchable layer 220 may be tapered in thickness. FIG. S discloses a top view of grip 200 . FIG. 6 discloses a cross sectional view of grip 200 taken from cross sectional line A to A of FIG. 5. Tapering the edges of skin layer 204 , backing layer 212 and 4-way stretchable material layer 220 allows for the edges to overlap when wrapping a railing or hand support system with grip 200 and at the same time to maintain a constant thickness of grip 200 despite the overlapping edges. In another embodiment, the edges are tapered but wrapped in such a way that they do not overlap to provide still more friction for the user. In still another embodiment, the lengthwise edges of skin layer 204 , backing layer 212 and 4-way stretchable layer 220 are not tapered for instances when the edges do not overlap.
[0045] [0045]FIG. 9 discloses a system of providing a secure, safe, releasably attachable grip on a railing. The system of the present invention can be utilized with any type of railing or hand support system 302 . Grip 300 of the present invention has a 4-way stretchable material layer 304 with an inner and outer surface, skin layer 306 which has an inner layer and an out layer, the inner layer of the skin layer 306 is permanently adhered to said outer surface of said 4-way stretchable material layer 304 . 4-way stretchable material layer 304 is releasably adhered to railing 302 .
[0046] [0046]FIG. 10 discloses another embodiment of a system of providing a secure, safe, releasably attachable grip on a railing. The system of the present invention can be utilized with any type of railing or hand support system 402 . Grip 400 of the present invention has 4-way-stretchable layer 404 with an inner and outer surface, backing layer 406 with an inner and outer surface, and skin layer 408 which has an inner surface and an outer surface, the inner surface of the skin layer 408 is permanently adhered to said outer surface of said backing layer 406 . The inner surface of backing layer 406 is permanently adhered to 4-way stretchable layer 404 . 4-way stretchable layer 404 is releasably adhered to railing 402 .
[0047] [0047]FIG. 11 discloses a method of enveloping the railing with the grip of the present invention. In one embodiment, grip 500 has alignment targets 506 along axis 510 parallel to lengthwise edge 508 of grip 500 . Next, alignment targets 504 are placed on railing 502 . Next, grip 500 is placed on the railing so that the center lengthwise axis of the grip is centered on the axis parallel to the length of railing 502 . Next, grip 500 alignment targets 506 are aligned with railing 502 alignment targets 504 . Finally, grip 500 has a width substantially similar to the circumference of railing 502 such that when grip 500 is folded around railing 502 edges 508 of grip 500 abut.
[0048] In another method of wrapping, FIG. 12 discloses a method of spirally wrapping a railing 602 with grip 600 . Next, grip 600 is wrapped, placing the tapered edge of grip 600 spirally around the railing such that the tapered edges of grip 600 overlap. The length of railing 602 may be fully covered by grip 600 such that the fully covers railing 602 and the thickness of grip 600 remains constant. In an alternative embodiment, grip 600 may be wrapped around the railing so that the edges do not overlap to provide additional friction to the user. | A device, method and system for a secure, comfortable grip on a railing or other hand support system. The device includes a skin layer permanently adhered to a 4-way stretchable material layer. The 4-way stretchable material layer is releasably adhered to a railing or other hand support system. A backing layer between the skin layer and the 4-way stretchable material layer can be inserted for greater comfort and friction. The grip of the present invention is designed to be releasably attachable to the railing or other hand support system. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to a method for manufacturing ink jet printheads and the product printheads derived therefrom, and, more particularly, to a method for electrodeposition passivation of ink channels in ink jet printheads and printheads with ink channels passivated by such method.
2. Description of the Related Art
Printers provide a means of outputting a permanent record in human readable form. A printing technique may generally be categorized as either impact printing or non-impact printing. A popular form of non-impact printing is referred to as ink jet printing. In ink jet printing, ink is ejected, most commonly by pressure, through a tiny nozzle to form an ink droplet that is deposited upon a paper medium. Such ink jet printing devices produce highly reproducible and controllable droplets, so that a droplet may be printed at a location specified by digitally stored data. Most commercially available ink jet printing systems may be generally classified as either "continuous jet" or "drop-on-demand" ink jet printing systems. In a continuous jet ink jet printing system, ink droplets are continuously ejected from the printhead and either directed to or away from the paper or other substrate depending on the desired image to be produced. In a drop-on-demand ink jet printing system, ink droplets are ejected from the printhead in response to a specific command related to the image to be produced.
Drop-on-demand ink jet printing systems are based upon the production of droplets by electromechanically induced pressure waves. The ink is typically stored in a reservoir or channel. A volumetric change in the ink fluid so stored is then induced by the application of a voltage pulse to an electromechanical material, such as a piezoelectric material, which is directly or indirectly coupled to the fluid. This volumetric change causes pressure/velocity transients to occur in the fluid and these are directed so as to produce a droplet that issues from the reservoir or channel, typically through an orifice. Since the voltage is applied only when a droplet is desired, these types of ink jet printing systems are referred to as drop-on-demand.
The use of piezoelectric materials in ink jet printers is well known. Most commonly, piezoelectric materials are used in a piezoelectric transducer by which electric energy is converted into mechanical energy by applying an electric field across the material, thereby causing the piezoelectric material to deform. This ability to deform piezoelectric material has often been utilized in order to force the ejection of ink from the ink reservoirs, passages or channels of drop-on-demand type systems. Illustrative patents showing the use of piezoelectric materials in ink jet printers include U.S. Pat. Nos. 3,857,049, 4,584,590, 4,825,227, 4,536,097, 4,879,568, 4,887,100, 5,227,813, 5,235,352, 5,334,415, 5,345,256, 5,365,645, 5,373,314, 5,400,064, 5,402,162, 5,406,319, 5,414,916, 5,426,455, 5,430,470, 5,433,809, 5,435,060, 5,436,648 and 5,444,467.
One drop-on-demand type ink jet printer configuration which utilizes the distortion of a piezoelectric material to eject ink includes a printhead forming an ink channel array in which the individual channels of the array each have side walls formed at least, in part, of a piezoelectric material. In the typical case of such an array, the channels are microsized and are arranged such that the spacing between adjacent channels is relatively small. In operation of this type printhead, ink is directed to and resides in the channels until selectively ejected therefrom. Ejection of ink from selected channels is effected due to the electromechanical nature of the piezoelectric side walls of the channels. Because piezoelectric material deforms when an electric field is applied thereacross, the side walls of selective channels may be caused to deform by applying an electric field across select ones thereof. The electric field may be so selectively applied by digital or other means. This deformation of side walls of select channels reduces the volume of the respective channels creating a pressure pulse in the ink residing in those channels. The resultant pressure pulse then causes the ejection of a droplet of ink from the front end of the particular channel adjacent the side walls across which the electric field is applied.
Many ink jet printheads also include a cover plate fixedly mounted on the front end of the printhead adjacent the ink channels. Extending through such a cover plate may be a plurality of orifices which comprise an array. In most ink jet printheads, each orifice in such an orifice array corresponds to one of the ink channels of the printhead. A cover plate is typically positioned abutting the printhead in a manner so that each orifice is in communication with a corresponding channel of the printhead. When a pressure wave is created in ink in a typical ink jet printhead due to electromechanical action or otherwise, an ink droplet is forcibly ejected from the ink jet printhead through the orifice. This type of orifice can form an appropriate ink droplet to create a desired impression as the droplet is thereby deposited on a selected medium.
In a typical configuration, the electrical conductors used to apply the electric field across the piezoelectric material of the channels extend to the edge of and are exposed within the walls of the channels. Accordingly, when conductive fluids, such as water-based inks are disposed within the channels of such ink jet printheads (such as described in U.S. Pat. Nos. 4,879,568, 4,887,100, 5,227,813 and 5,235,352, which are incorporated herein by reference), electrical current flows through the fluid and degradation in performance will occur unless there is complete protection or isolation of the active piezoelectric material or electrical conductors on the piezoelectric material from the conductive fluids. Degradation can consist of bubble formation upon the application of an electric field to actuate the ink carrying channels resulting in printing errors. Degradation can also consist of shorting of the electric field in the piezoelectric material which is in contact with the conductive fluid. Degradation can further consist of chemical attack of the active piezoelectric material by the conductive fluid. The current flow and degradation in performance results in printing errors. There is a need, therefore, for an ink jet printhead in which the electrical conductors disposed within the printhead are isolated from the ink or other fluid disposed within the channels.
SUMMARY OF THE INVENTION
The present invention is directed to a method for creating a passivation coating on the surfaces of channels of a workpiece.
In a preferred embodiment, the method of the present invention is directed to creating a passivation coating on the surfaces of channels in an ink jet printhead so as to isolate the electrical conductors in the printhead from the fluid disposed within the channels.
In one embodiment of the method of the present invention, a passivation coating is created inside the channels of an ink jet printhead by applying a controlled thickness passivation coating over any exposed metal surfaces in the channels by means of an electrodeposition or electrocoating process.
In a preferred embodiment of the present invention, the exposure of the metal surfaces in the channels is minimized by means of electropolishing prior to applying the passivation coating to the exposed metal surfaces. Other embodiments of the present invention may not allow fort he electropolishing process but would still benefit from the electrodeposition process.
BRIEF DESCRIPTION OF THE DRAWINGS
Other advantages and features of the invention will become more apparent with reference to the following detailed description of presently preferred embodiments thereof in connection with the accompanying drawings, wherein like reference numerals have been applied to like elements, in which:
FIG. 1 is a perspective view of a schematically illustrated ink jet printhead to which a passivation coating may be applied according to the method of the present invention;
FIG. 2 is an enlarged partial cross-sectional view of the ink jet printhead of FIG. 1 taken along line 2--2 and illustrating a parallel channel array of the ink jet printhead of FIG. 1; and
FIG. 3 is a schematic view of an ink jet printhead connected to a voltage supply to carry out the method of the present invention.
FIG. 4 is a schematic view of an ink jet printhead connected to a voltage supply to carry out the method of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Electrodeposition is an electrolytic process by which organic materials may be coated from aqueous suspension, or solution, onto a conductive substrate under the influence of electricity. The process is self-regulating and utilizes direct current to deposit organic materials, such as resins, on a conductive substrate. The process also involves the phenomenon of electrophoresis which means the migration of colloidal or suspended particles in an electric field. Depending upon the type of particles to be deposited, the particles will migrate either to the anode which is called anaphoresis or to the cathode which is called cataphoresis. In either case, the process requires ionizable resins that can be diluted with water and deposited from an aqueous medium under the influence of an electric current.
In a cataphoretic deposition process, the part to be coated is made the cathode in the electrical structure. In an anaphoretic deposition process, the part to be coated is made the anode in the electrical structure. In both cases, the small particles to be deposited are called micelles and typically have a size smaller than 200 nm and bear a surface charge. In a cataphoretic deposition process, the micelles are disposed in a cataphoretic solution and the micelles migrate by electrophoresis toward the cathode at a rate in the range of micrometers per second when an electric field is applied at a level greater than 1 volt/mm. Some dissolution of the anode is possible during this process. When the micelles reach the cathode, their positive charges are neutralized by hydroxide ions produced by the electrolysis of water. The micelles then become destabilized, and coalesce on the surface of the cathode to form a self-limiting, insulating film that emerges nearly dry from the coating bath. The small size of the individual micelles results in good packing densities, even coatings and elimination of pinholes. As a result, the process produces a highly uniform and defect-free coating. The self-limiting nature of the electro-deposited coatings is mainly dependent on the voltage of the electric field applied to the cataphoretic bath, the coating time and the temperature of the cataphoretic bath. As the continuous film begins to form, the electric field driving the electrophoresis gradually diminishes since more of the cell voltage drops across the growing film than across the bath emulsion. The film growth continues until its resistance is so high that the electric field across the cataphoretic bath is too low to deliver any more micelles to the cathode. Once the film growth is completed, the film is thermally, photochemically or otherwise set or cured by techniques well known to those of ordinary skill in the art.
In a preferred embodiment of the present invention, the electrodepositable film forming resins that may be utilized in the method include acrylates, epoxies and novolacs. These and other suitable resins are commercially from Shell Chemical Company, DuPont Company and Dow Chemical Company. Those of ordinary skill in the art will recognize that for a resin to be electrodepositable, the resin must contain a distribution of ionizable groups along its molecular chain. Those of ordinary skill in the art will also recognize that particularly preferred electrodepositable resins include those that have superior coating performance, uniformity on complex surfaces, freedom from pinholes and allow control of coating thicknesses.
Electropolishing is a process by which the surface of metal part is smoothed and enhanced by making it an anode in a suitable electrolyte. Electropolishing is the reverse of electrodeposition and is a process in which metal is removed from the surface of a metal part. Typically, an acid solution is used as the electrolyte. A bias voltage is applied which causes metal ions to leave the surface of the part to be electropolished. The released metal ions travel through the electrolyte solution to the cathode.
Referring now to the drawings wherein thicknesses and other dimensions have been exaggerated in the various figures as deemed necessary for explanatory purposes and wherein like reference numbers designate the same or similar elements throughout the several views, an ink jet printhead 10 according to the present invention is shown in FIG. 1. The ink jet printhead 10 may be used in connection with the devices disclosed and claimed in U.S. Pat. Nos. 5,227,813, 5,235,352, 5,334,415, 5,345,256, 5,365,645, 5,373,314, 5,400,064, 5,402,162, 5,406,319, 5,414,916, 5,426,455, 5,430,470, 5,433,809, 5,435,060, 5,436,648 and 5,444,467, the entire disclosures of which are hereby incorporated herein by reference. As shown in FIG. 1, the ink jet printhead 10 includes a main body portion 12 which is aligned, mated and bonded to an intermediate body portion 14 which, in turn, is aligned, mated and bonded to a top body portion 16.
A plurality of vertical grooves of predetermined width and depth are formed through the intermediate body portion 14 and the main body portion 12 to form a plurality of pressure chambers or channels 18 (not visible in FIG. 1), thereby providing a channel array for the ink jet printhead 10. In conventional manner, the channels 18 are in fluid communication with external fluid conduit 60 and ink supply 62.
The ink jet printhead 10 further includes a front wall 20 having a plurality of orifices 22 extending therethrough. Each orifice 22 is in fluid communication with a corresponding one of said plurality of channels 18, thereby providing fluid ejection nozzles for the ink jet printhead 10.
FIG. 2 shows an enlarged partial cross-sectional view of the ink jet printhead 10 taken along line 2--2 of FIG. 1. The ink jet printhead 10 includes a plurality of parallel spaced channels 18, each channel 18 vertically extending from the top body portion 16, along the intermediate body portion 14 and part of the main body portion 12 and extending lengthwise through the ink jet printhead 10. The main body portion 12 may be constructed of inactive or active material such as unpolarized or poled piezoelectric material and the top body portion 16 may be constructed of an inactive material such as unpolarized piezoelectric material. Separating adjacent channels 18 are sidewall actuators 24, each of which include a first sidewall section 26 and a second sidewall section 28. The first sidewall section 26 may be constructed of an inactive or active material, for example unpolarized or poled piezoelectric material, and, in a preferred embodiment of the present invention, is integrally formed with the body portion 12. When the first sidewall section 26 is constructed of an active poled piezoelectric material, it may be formed of lead zirconate titanate (PZT), polarized in direction "P" perpendicular to the channels 18. The second sidewall section 28, is formed of an active material, for example, poled piezoelectric material such as lead zirconate titanate (PZT), polarized in direction "P" perpendicular to the channels 18.
Mounted to the top side of each first sidewall section 26 is a metallized conductive surface 30, for example a strip of metal. Similarly, metallized conductive surfaces 32 and 34, also formed of a strip of metal, are mounted to the top and bottom sides, respectively, of each second sidewall section 28. A first layer of a conductive adhesive 36, for example, an epoxy material, is provided to conductively attach the metallized conductive surface 30 mounted to the first sidewall section 26 and the metallized conductive surface 34 mounted to the second sidewall section 28. Finally, the bottom side of the top body portion 16 is provided with a metallized conductive surface 38 which, in turn, is conductively mounted to the metallized conductive surface 32 of the second sidewall section 28 by a second layer of a conductive adhesive 40. In this manner, a series of channels 18, each channel being defined by the piezoelectric material of the main body portion 12 along its bottom, the layer of conductive adhesive 40 along its top and a pair of sidewall actuators 24 is provided. Each sidewall actuator 24 is shared between adjacent channels 18.
Prior to assembling an electronic controller, the front cover 20, the external conduit 60 and the ink supply 62 to the printhead 10, a passivation coating may be applied to all exposed metallized conductive surfaces that come into contact with the conductive fluid or ink disposed in the channels 18 according to the present invention.
As shown schematically in FIG. 3, the printhead 10 is placed in a polymer deposition solution so that the polymer deposition solution 64 fills the channels 18. A voltage supply 66 is connected to the printhead 10. According to one embodiment of the present invention, the lead 68 of the voltage supply 66 is a negative lead and is connected to the exposed surfaces of the metallized conductive surfaces 30 which are electrically connected to conductive surfaces 34 through the layer of conductive epoxy 36. The metallized conductive surfaces 30 and 34 and the conductive epoxy 36 thus become the cathode. The lead 70 of the voltage supply 66 is positive relative to lead 68 and is either connected to ground or connected to the exposed surface of the metallized conductive surface 32 which is electrically connected to metallized conductive surface 38 through the layer of conductive epoxy 40, making the metallized conductive surfaces 32 and 38 and the layer of conductive epoxy 40 into the anode. Upon energizing the voltage supply 66, micelles in the polymer deposition solution 64 migrate to the cathodes and are deposited on the conductive surfaces 30, 34 and 36 to form passivation coatings 72. The process continues until all exposed surfaces of the conductive surfaces 30, 34 and 36 are covered by the passivation coatings 72. Once the exposed surfaces of the conductive surfaces 30, 34 and 36 are covered and all pinholes in the passivation coatings are filled, the electric current in the channels is reduced and the process slows down.
After the passivation coating 72 is applied, the printhead 10 is removed from the polymer deposition solution 64 and the passivation coatings 72 are thermally or photochemically cured.
After the passivation coatings 72 are cured, the printhead 10 can be returned to the polymer deposition solution 64 and the polarity of the voltage supply 66 may be reversed making the conductive surfaces 32, 38 and 40 into the cathode. Upon energizing the voltage supply 66, micelles in the polymer deposition solution 64 migrate to the cathode to form passivation coatings 74. The electric field generated upon the reversal of the polarity of the voltage supply 66 is weaker than the original electric field so that the passivation coating 74 is deposited on the conductive surfaces 32, 38 and 40 at a slower rate.
After the passivation coatings 74 are applied, the printhead 10 is removed from the polymer deposition solution 64 and the passivation coatings 74 are thermally or photochemically cured.
Those of ordinary skill in the art will recognize that all conductive surfaces in the printhead 10 can be made into the cathode and coated simultaneously. In this instance, the voltage supply would be grounded externally.
Those of ordinary skill in the art will recognize that the passivation coatings 72 can be applied to the conductive surfaces 30, 34 and 36 prior to the attachment of the top body portion 16.
While the present invention has been described in terms of a cataphoretic process in which the metallized or other conductive surface to be coated was made the cathode, those of ordinary skill in the art will recognize that the passivation coatings 72 and 74 can be generated through an anaphoretic deposition process in which the metal to be coated is made the anode. Those of ordinary skill in the art will also recognize that the polymer deposition solution 64 that fills the channels 18 can be formulated to include both anodic and cathodic micelles. In this manner, when the voltage supply 66 is energized, a passivation coating will simultaneously be deposited on all conductive surfaces in the printhead.
In a preferred embodiment of the present invention, the metallized surfaces in the ink jet printhead 10 are electropolished prior to the deposition of the passivation coatings 72 and 74. According to the electropolishing step, the ink jet printhead 10 is placed in an acid bath and a voltage supply is attached to the printhead in a manner to make the exposed metallized surfaces into the anode. When the voltage supply is energized, a slight amount of the metal of the metallized surfaces, such as surfaces 30 and 34 will be removed or etched at the fluid interface which will not degrade the performance of the printhead 10. This will minimize the amount of exposed metal to be coated by the passivation coatings. Certain embodiments of the present invention may not allow for the electropolishing process but would still benefit from the electrodeposition process.
While the present invention has been described with reference to a presently preferred embodiment, it will be appreciated by those of ordinary skill in the art that various modifications, changes, alternatives and variations may be made therein without departing from the spirit and scope thereof as defined in the appended claims. | A method for manufacturing ink jet printheads and the product printheads derived therefrom. The method involves the electrodeposition passivation of ink channels in ink jet printheads. | 2 |
PRIOR RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. Ser. No. 10/666,731, filed Sep. 19, 2003, which claims priority to provisional application Ser. No. 60/453,611, filed Mar. 11, 2003, which applications are incorporated herein in their entireties by reference thereto.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Use
[0003] This invention relates to electronic candles. This invention also specifically relates to a system and method for the commercialization of electronic candle illuminations. This invention also relates to the commercialization of electronic candles wherein payments are made for lighting the candles for a certain period of time.
[0004] 2. Discussion of the Background and Prior Art
[0005] Traditionally, wax candles, such as votive candles and tapers, have been used for memorialization and devotional purposes. Religious institutions generally provide for the purchase and lighting of the wax candles. Purchasers of the candles would make a donation of a desired or recommended amount, which amount is usually deposited in a collection box in order to acquire and light the wax candle.
[0006] Wax candles produce pollutants and soot, are a fire hazard. Insurance is costly where wax candles are in general use. The candle art turned to electronic candles, in which the user would touch or turn-on a candle that would then illuminate. Examples of electronic candles are disclosed in U.S. Pat. No. 6,066,924, U.S. Pat. No. 6,017,139, U.S. Pat. No. 5,863,108, U.S. Pat. No. 4,617,614 and U.S. Publication Application 2004/0179355 to Gabor Lederer, the inventor of the present invention. U.S. Patent Publication No. 2002/001373 to Shin et al. discloses an e-commerce method for authorizing the lighting of and paying for a wax candle at a remote location. The wax candle is lit and extinguished by one other then the user-purchaser. The user-purchaser is then expected to visit the burning candle at the remote location. This prior art method was abstruse and designed expressly for remote and candle illumination
[0007] The art directed to user-purchaser illumination provides the improvement of placing a motion sensor in the collection box. The motion sensor senses any object deposited into the collection box. A user by merely inserting a coin, bill, or piece of paper or any object by the user in the collection box effect actuation of an electronic candle for illumination. This prior art arrangement is shown in FIG. 1 . This prior art method did not adequately control the payment for the illumination, and was unsatisfactory as a practical business means to both the religious institution and the electronic candle manufacturer. The art desired a method for the realistic commercialization of the illumination of electronic candles.
[0008] It is therefore a principal object of the present invention to provide a system and method for the commercialization of illuminations of electronic candles.
[0009] It is another object of the present invention to provide an improved electronic candle for the aforesaid commercialization.
[0010] It is another object of the present invention to provide a system and method as aforesaid, wherein the electronic candles are provided and maintained at religious institutions.
[0011] It is another principal object of the present invention to provide automated collection and pilfer control for the aforesaid commercialization of electronic candles, particularly for religious institutions.
[0012] It is yet another object of the present invention to provide an improved electronic candle and system which is of practical design, readily installed and operated and yet safe and practical in use.
[0013] The aforesaid objects are achieved by the present invention.
SUMMARY OF THE INVENTION
[0014] This invention in one principal aspect is a system for the commercialization of electronic candle illuminations wherein payment is validated to actuate at least one candle of a plurality of candles. Once the candle is actuated for illumination, the user touches one candle to effect illumination for the prescribed time period. A chart or other visual means informs the user of the cost and committed illumination time period in order for the user to make an informed decision regarding payment. A currency validator or credit card payment validator senses the payment amount sends an electronic signal to a control unit or central unit wherein the illumination time is calculated, and in turn, an electronic signal is transmitted to the candles to actuate the candles for the prescribed time corresponding to the payment. The user touches a desired selected candle which is, by such touching, illuminated for the prescribed period. With illumination of the one selected candle, the remaining unlit candles are de-actuated. The system is made for each present or subsequent user—purchaser to make accurate payment and effect illumination of the related electronic candle.
[0015] The system induces encrypted or means for automatically providing encoded account statement of the candles illumination times and the corresponding payments represent those illuminations. The manufacturer of the electronic candles decrypts the account statement for confirming royalty or lease payments.
[0016] A stand is provided for mounting the candles in an arrangement. This arrangement provides the user with a diverse selection of positions from which to select the candle for illumination. The candles may also contain different indicia. This permits the user to select a candle that is most consistent with their devotional, memorial or emotional needs and desires.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a block diagram showing the prior art method of electronic candle illumination at a religious institution.
[0018] FIG. 2 is a block diagram of the overall commercialization system of the present invention; and
[0019] FIG. 3 is a detailed block diagram of the candle illumination system of the present invention.
DESCRIPTION OF THE INVENTION
[0020] Referring to FIG. 1 , there is shown a prior art electronic candle illumination system 10 . System 10 is based on a collection box 11 having slot 12 of conventional construction. An object motion sensor 13 is mounted in the side of collection box 11 . The user 14 inserts any object, e.g., coins, paper currency, token, paper, medals and the like, into slot 12 . The sensor senses the object and in turn actuates at least one electronic candle 15 for illumination. The user then turns on the electronic candle 15 of their selection. This system did not provide a commercially viable system for candle illuminations, particularly for religious institutions and memorialization forums, e.g. cemeteries and memorials.
[0021] Referring to FIGS. 2 and 3 , there is shown the system for the commercialization of electronic candies 20 of the present invention. System 20 includes a plurality of electronic candles, e.g. 21 , 22 and 23 . Electronic candles 21 - 23 imitate traditional wax candles, such as a votive or memorial candle, as will be further described hereinafter. A central unit or control unit 25 is another principal component of the system. Central unit 25 includes a CPU 26 , keypad 27 , display 28 , non-volatile memory 29 , I 2 C interface 30 , real-time clock and alarm interface 31 and a dual serial port 32 . The components 26 - 32 are assembled and programmed by means well know to one skilled in the control system art. While the invention is described as having an 12 Centrifuge, it is within the broad contemplation of the invention to utilize other commercialization references known in the electronic art.
[0022] A currency/payment validator 40 is a further principal component of the present invention. Currency/payment validator 40 may be of conventional design and construction wherein a bill in any one of several denominations is inserted in a slot (not shown) in currency/payment validator 40 . The inserted bill is acknowledged by an alpha-numeric display or illumination element (not shown). The inserted bill sends an electronic signal to central unit 25 . A candle illumination rate schedule 35 advises the user 28 as to the illumination time for a prescribed payment. The electronic signal from currency/payment validator 40 to central unit 25 informs the central unit of the candle illumination period for which the prescribed payment was made. Central unit 25 in turn actuates candles 21 - 23 for that prescribed illumination period. The user 28 then touches a selected candle, e.g. 21 and in so doing, illuminates the selected electronic candle for the prescribed time period.
[0023] A power supply 42 , back-up battery power source 43 and alarm circuit 44 complete the assembly provided to and maintained at religious institutions 50 . A hand held unit 51 may be plugged into central unit 25 for the purpose of recording the illumination times and/or payments mode. This account function may be encrypted in or encoded by central unit 25 . A manufacturer 50 may retain decryption means to read the encrypted account information. The encrypted account information may be stored on a hand held device provided by manufacturer 50 . A supplier 65 is under contract with the manufacturer to provide and manufacture the electronic candle 21 - 23 , central unit 25 and currency/payment validator 40 , as well as to take periodic account ready by means of hand held device 51 , permit to a contractual arrangement with the manufacturer 50 and the religious institutions.
[0024] The present system 20 is provided on the aforesaid manner, which operation is desired is further discussed hereinafter.
[0025] One preferred electronic candle useful in the present invention is that shown and described in U.S. Pat. No. 6,017,139 granted Jan. 25, 2000 to Gabor Lederer, the invention herein, which disclosure is incorporated in its entirety herein by reference thereto. This electronic candle includes a spring loaded switch and timer element, wherein the user merely touches or presses down on the candle housing to effect illumination for the prescribed time period. In the present invention, the electronic candle is only first actuated after the currency/payment validator 40 validates the actual and correct currency payment or donation. Touching or otherwise manipulating the selected illuminated electronic candle will not interfere with the continue illumination for the payment prescribed period of time.
[0000] The Central Unit Operation
[0026] When currency/payment validator 40 senses a non-counterfeit bill and determines its face value, an electronic signal commensurate with the face value of the bill is sent to the central unit 25 . The central unit calculates the prescribed illumination time for the currency value of that bill. The central unit then enters an electronic “ready to turn on” signal to every candle 21 - 23 . The user then selects and turns on the selected electronic candle by pressing the top of the candle housing. This illumination of the candle will also send a recognition signal to the central unit 25 . The recognition signal identifies the illuminated candle and the first of the illumination, as well as the illumination time. This information is stored in the central unit memory. The central unit then sends a “not ready” or “disabled” signal to the other candles. None of the other candles can be turned on until a new “ready to turn on” signal is generated. The central unit 25 tracks the illumination history of every candle. After the prescribed illumination time has elapsed, the central unit 25 sends a “turn off” signal to the afore-discussed illuminated candle. In order to insure user recovery in the event of power failure, every illumination start time and illumination lapse period is stored in the instrument, and updated in a non-volatile memory 29 every ten milliseconds.
[0000] The CPU and Currency Validator Interface
[0027] The currency/payment validator 40 can recognize different bills. Validation is set for the customary are the $1, $5, $10 and $20 bills. The currency/payment validator 40 , however, may be set for any currency including foreign currency in diverse face values. The operator or religious institutions are able to dedicate any time interval to any bill value and store them in the memory of the CPU through push-buttons and LEDs displays (on the front panel of the unit). By pressing the “$” and up/down sets the dollar value (upper display), by pressing only the up/down, the time can be set (lower display), pressing “Enter” the desired (set) values will be stored. By pressing “Check” and the “$” button, the displays will show the currently existing settings. By pressing “Check” and the up/down button, the current time setting can be displayed. The moneys collected since the last reading (or collection) can be read by pressing “Enter” and “Check” buttons. The sum total amount that shows should have been collected and disposed in the money collection box at that time since the collection box was last emptied. To restart this type of counting (from collection to collection), press “Enter” and “Check” again. The total amount of the collected moneys can be read in a coded form only by pressing the “check” button. In this mode, the displays (upper/lower) will show a combination of numbers and letters. Inserting the numbers/letters will decode them to a real dollar value. This amount is the total collection from a pre-set time (factory set or password protected settings) and is achieved by a separate program.
[0028] It is understood that the above example and drawings are merely exemplary of the present invention and that changes in the method, system and apparatus and afore-discussed may be made without departing from the scope of the present invention as defined in the following claims.
[0000] Collection Accounting and Pilfer Control
[0029] It is an unfortunate fact of present reality that church collection boxes are pilfered. The electronic candle art desires a commercialization system with automated collection accounting and pilfer control.
[0030] In the present invention, there is provided a counter operably connected to the currency/payment validator 40 by electro-mechanical means well known in the art. When the collection box is opened, the counter records the date and time of the opening and the currency accumulated in the collection box since the last opening. This information is provided to the religious institution, the supplier and/or the manufacturer by electronic transmission means well known in the art. Non-wireless communication is also within the contemplation of the present invention. This collection box accounts information may also be encoded by the central processing units. A decryption means may be provided to the religious institution, supplier and/or manufacturer, whereby the electronically determined accounts and the physically accumulated monies are reconciled. In the event that any one collection does not correlate with the electronic accounts, the religious institution is able to identify the specific collector responsible for the deficient collection. The electronic accounts also permits a ready determination regarding distribution of the collected monies among the religious institutions, suppliers and manufacturer.
[0031] The automated system also contemplates providing an accounting for a pre-selected period of time, e.g. a month or a year, coins with the terms of commercialization between the manufacturer and the religious institution.
[0032] It is also within the contemplation of the present invention for the manufacturer to provide the services and activities of the supplier.
[0033] It is also within the contemplation of the present invention for the religious institution to purchase the electronic candles from the manufacturer and have the manufacturer service the electronic candles and the automated controls and accounting. | A system provides for the commercialization of electronic candles in religious institutions or memorial locations wherein a prescribed payment for a predetermined illumination period is verified or validated and an electronic signal then actuates at least one of the electronic candles. The user selects the desired candle for illumination and touches the selected candle for illumination for the prescribed period. A payment account statement is periodically transmitted to the religious institution or manufacturer to confirm actual payments with the electronic statement of payments to control pilferage. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
For efficiency amplification, a refrigerant-side control for condensers on air condition or refrigeration systems is disclosed. More specifically, by relying on principles of fluid mechanics and turbulent flow of a refrigerant, the subject apparatus achieves maximum refrigerant operational conditions while reducing energy consumption by the system.
2. Description of the Background Art
Various devices relying on standard refrigerant recycling technologies have been available for many years. Refrigeration and heat pump devices, having both cooling and heating capabilities, are included within the general scheme of the subject invention, however, the subject device relates preferably to refrigeration systems. Within the limits of each associated design specification, heat pump devices enable a user to cool or heat a selected environment or with a refrigeration unit to cool a desired location. For these heating and cooling duties, in general, gases or liquids are compressed, expanded, heated, or cooled within an essentially closed system to produce a desired temperature result in the selected environment.
Traditional sub-coolers partially cool the refrigerant prior to the expansion device and subsequent evaporator. Such refrigerant cooling has been shown to increase the efficiency of the heat transfer within the evaporator. Various types of sub-coolers exist, but the most common form cools the refrigerant by drawing in cooler liquid to surround the warmer refrigerant.
SUMMARY OF THE INVENTION
An object of the present invention is to disclose a refrigerant system efficiency amplifying apparatus.
Another object of the present invention is to describe an apparatus that decreases the amount of energy required to power a compressor in a refrigeration of heat pump system.
A further object of the present invention is to relate an apparatus that decrease the compression ratio for a compressor in a refrigeration of heat pump system, thereby increasing the efficiency and economy of the system.
Still another object of the present invention is to produce an apparatus that introduces turbulent flow into the liquefied refrigerant within a refrigeration or heat pump system, thus increasing the operational conditions for the refrigerant that favor enhancing efficiency of the system.
Yet a further object of the present invention is to disclose a turbulence producing device that is located in a stream of liquefied refrigerant that comprises a disk with a central aperture that permits the passage of refrigerant and a set of fixed angled blades formed in the disk that project into the central aperture.
Disclosed for use with a heat exchange system (refrigeration or heat pump devices) having at least a compressor, condenser, evaporator, expansion device, and circulating refrigerant, is an efficiency enhancing apparatus comprising a liquid refrigerant containing vessel formed from a cylinder capped by a top end cap and a bottom end cap, wherein the vessel is positioned in the heat exchange system between the condenser and the evaporator. A refrigerant entrance is located in a top region of the vessel and a refrigerant exit is located in a bottom region of the vessel. Preferably, the refrigerant exit is positioned to be no lower than approximately a lowest point in the condenser.
Provided are first means for generating turbulence in the refrigerant associated with the top region and second means for generating turbulence in the refrigerant associated with the bottom region. Preferably, the first means comprises means for generating a rotational motion of the entering refrigerant within the vessel. The second means comprises a set of fixed angle blades positioned in the bottom region of the vessel. The set of blades produces turbulence in the refrigerant as the refrigerant exits the vessel. More particularly, the second means comprises a disk located proximate the refrigerant exit, a central aperture formed in the disk that permits the passage of exiting refrigerant, and a set of fixed angled blades formed in the disk that project into the central aperture, wherein the set of blades adds turbulence to the exiting refrigerant.
Other objects, advantages, and novel features of the present invention will become apparent from the detailed description that follows, when considered in conjunction with the associated drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a traditional or "Prior Art" refrigeration system.
FIG. 2 is a schematic view of a refrigeration system adapted with the subject invention.
FIG. 3 is a cross-sectional view of the subject unit.
FIG. 4 is a cross-sectional view of the subject unit taken along line 4--4 in FIG. 3.
FIG. 5 is a perspective view of the "turbulator" of the subject invention.
FIG. 6 is top view of the "turbulator" of the subject invention.
FIG. 7 is cross-sectional view of the "turbulator" of the subject invention taken alone line 7--7 in FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Before a detailed description of the subject invention is presented, a rationale for the subject systems amplification of efficiency is presented. Also, it must be noted that even though a refrigeration system is utilized in the figures and detailed description of the subject invention, any heat pump system can be fitted or adapted with the subject device.
Referring now to FIG. 1 for a generalized "Prior Art" refrigeration system, to quickly appreciate the benefits of the subject device, a brief description of the functioning of a traditional refrigeration system is supplied. An expandable-compressible refrigerant (no refrigerant has been found that has not worked successfully with the subject device) is contained and cycled within an essentially enclosed system comprised of various refrigerant manipulating components. When a liquid refrigerant expands (within a heat exchanger or evaporator) to produce a gas it increases its heat content at the expense of a first surrounding environment which decreases in temperature. The heat rich refrigerant is transported to a second surrounding environment and the heat content of the expanded refrigerant released to the second surroundings via condensation (within a heat exchanger or condenser), thereby increasing the temperature of the second surrounding environment. As indicated, even though the subject invention is used preferably with a refrigeration system, adaptation to a generalized heat pump system is considered to be within the realm of this disclosure. Therefore, for a heat pump, heating or cooling conditions are generated in the first and second environments by reversing the process within the enclosed system.
As indicated, FIG. 1 depicts a traditional refrigeration system, but, again, it must be stressed that the subject invention is suitable for modifying any equivalent heat pumps systems in an analogous manner. The four basic components in all systems are: a compressor CO; a condenser (heat exchanger) CX; an evaporator (heat exchanger) EX; an expansion valve EV; and the necessary plumbing to connect the components. These components are the same regardless of the size of the system. Gaseous refrigerant is compressed by the compressor CO and transported to the condenser CX which causes the gaseous refrigerant to liquefy. The liquid refrigerant is transported to the expansion valve EV and permitted to expand gradually into the evaporator EX. After evaporating into its gaseous form, the gaseous refrigerant is moved to the compressor CO to repeat the cycle.
A lower compression ratio reflects a higher system efficiency and consumes less energy during operation. During compression the refrigerant gas pressure increases and the refrigerant gas temperature increases. When the gas temperature/pressure of the compressor is greater than that of the condenser, gas will move from the compressor to the condenser. The amount of compression necessary to move the refrigerant gas through the compressor is called the compression ratio. The higher the gas temperature/pressure on the condenser side of the compressor, the greater the compression ratio. The greater the compression ratio the higher the energy consumption. Further, the energy (Kw) necessary to operate a cooling or heat exchange system is primarily determined by three factors: the compressor's compression ratio; the refrigerant's condensing temperature; and the refrigerant's flow characteristics.
The compression ratio is determined by dividing the discharge pressure (head) by the suction pressure. Any change in either suction or discharge pressure will change the compression ratio.
It is noted that for refrigeration systems or any heat pump systems when pressure calculations are performed they are often made employing absolute pressure units (PSIA), however, since most individuals skilled in the art of heat pump technologies are more familiar with gauge pressure (PSIG), gauge pressures are used as the primary pressure units in the following exemplary calculations. In the traditional refrigeration system shown in FIG. 1, a typical discharge pressure of 226 PSIG (241 PSIA) is found at P1 and a typical suction pressure of 68 PSIG (83 PSIA) is measured at P2. Dividing 226 PSIG by 68 PSIG yields a compression ratio of about 2.9.
The condensing temperature is the temperature at which the refrigerant gas will condense to a liquid, at a given pressure. Well known standard tables relate this data. In the FIG. 1 traditional example, using R22 refrigerant, that pressure is 226 PSIG. This produces a condensing temperature of 110° F. at T1. At 110° F., each pound of liquid freon that passes into the evaporator will absorb 70.052 Btu's. However, at 90° F. each pound of freon will absorb 75.461 Btu's. Thus, the lower the temperature of the liquid refrigerant entering the evaporator the greater its ability to absorb heat. Each degree that the liquid refrigerant is lowered increases the capacity of the system by about one-half percent.
Well known standard tables of data that relate the temperature of a liquid refrigerant to the power required to move Btu's per hour show that if the liquid refrigerant is at 120° F., 0.98 hp will move 22873 Btu's per hour. If the liquid refrigerant is cooled to 60° F., only 0.2 hp is required to move 29563 Btu's per hour.
Additionally, Refrigerant flow through the refrigerant system, in most heat pump systems, is laminar flow. Traditional systems are designed with this flow in mind. However, a turbulent flow is much more energy efficient as known from well established data tables.
Referring now to FIG. 2, there is shown a preferred embodiment of the subject device 1 fitted into a traditional refrigeration system. The primes denote equivalent features (CO'=compressor; CX'=condenser; EX'=evaporator; and EV'=expansion valve), but with the subject invention fitted into the system between the condenser CX' and the evaporator EX'. The subject system stores excess liquid refrigerant (that is normally stored in the condenser) in a holding vessel 3, thus giving an increased condensing volume (usually approximately 20% more condensing volume), thereby cooling the refrigerant more (a type of sub-cooling). By adding this extra cooling the subject system reduces the discharge pressure and suction pressure. For discharge at P1' the pressure is 168 PSIG (183 PSIA) and for suction at P2' the pressure is 60 PSIG (74 PSIA). With these discharge and suction pressures, the compression ratio calculates to be 2.5. For the traditional refrigeration system shown in FIG. 1, the previously calculated compression ratio was 2.9. This shows a reduction in compression work of about 17%.
Concerning the condensing temperature for the subject adapted system, the liquid refrigerant temperature at T1' is about 90° F. (lowered from the 110° F. T1 noted above for the traditional system). The 20° F. drop in liquid refrigerant temperature yields a 10% increase in system capacity (20° F. times one-half percent for each degree, as indicated above). This was accomplished by the increased condensing volume provided by the subject device.
The subject invention influences the flow of the liquid refrigerant. Normally, when a vessel is introduced into a fixed pressure system (usually, for sub-cooling) a reduction in the system's capacity occurs because most fixed head pressure systems utilize a fixed orifice or capillary type expansion device. Such devices require pressure to force a proper volume of refrigerant through them in order to maintain capacity. The pressure is generated by the compressor. The greater the demand for pressure the greater the demand for energy (Kw).
With the adaptation of a fixed head pressure heat pump system by the subject device, the capacity is maintained. The capacity is maintained due to increased refrigerant velocity, volume, and refrigerant Btu capacity because of lower condensing temperature and an introduced spiral turbulent flow, rather than a straight laminar flow. As is well know in fluid dynamics, turbulent flow has an average velocity that is far more uniform than that for laminar flow. In fact, far from being a parabola, as in laminar flow, the distribution curve of the boundary region for a flowing liquid with turbulent flow is practically logarithmic in form. Thus, for turbulent motion, at the boundaries where the eddy motion must reduce to a minimum, the velocity gradient is much higher than in laminar type flow. With the subject device and its influence on refrigerant flow, the hotter the condensing temperature and the higher the load, the better the adapted system functions.
As seen in FIG. 3, in particular, the subject invention comprises a vessel 1 with an internal volume 3 and fabricated usually from a cylinder 5 and top 10 and bottom 15 end caps of suitable material such a metal, metal alloy, or natural or synthetic polymers. Generally, the top 10 and bottom 15 end caps are secured to the cylinder 5 by appropriate means such as soldering, welding, brazing, gluing, threading and the like, however, the entire vessel 1 may be formed from a single unit with the cylinder 5 and top 10 and bottom end caps as a unitized construction.
A liquid refrigerant entrance 20 and a liquid refrigerant exit 25 penetrate the vessel 1. Preferably, the refrigerant entrance 20 is located in a top region of the vessel 1. The top region is defined as being approximately between a midline of the cylinder 5, bisecting the cylinder 5 into two smaller cylinders, and the top end cap 10. Although FIG. 3 depicts the refrigerant entrance 20 as penetrating the cylinder 5, the entrance may penetrate the top end cap 10. Preferably, the refrigerant exit 25 is located in a bottom region of the vessel 1. The bottom region of the vessel 1 is defined as being approximately between the midline, above, and the bottom end cap 15. Although other locations are possible, the refrigerant exit 25 is preferably located proximate the center of the bottom end cap 15.
Usually, the bottom end cap 15 has an angled or sloping interior surface 30. However, the bottom end cap 15 may have an interior surface of other suitable configurations, including being flat.
Liquid refrigerant liquefied by the condenser CX' enters into the vessel 1 via the refrigerant entrance 20 and the associated components. The associated entrance components comprise a refrigerant delivery tube 35 and entrance fitting 40 that secures the vessel 1 into the exit portion of the plumbing coming from the condenser CX'. The entrance fitting 40 is any suitable means that couples the subject device into the plumbing in the required position between the condenser CX' and the evaporator EX'.
The refrigerant delivery tube 35 is configured to generate rotational motion in the entering refrigerant. The tube 35 penetrates into the top region and is formed into a curved configuration and generally angled down to deliver the entering refrigerant along a path suitable for generating a rotational motion of the refrigerant within the vessel 1 (as seen in FIG. 4). Other equivalent configuration of the tube 35 that generate such a rotational refrigerant motion are contemplated to be within the realm of this disclosure.
To view the level of the liquid refrigerant within the vessel 1, a sight glass 45 is provided. The glass 45 is mounted is the cylinder 5 at a position to note the refrigerant level.
The refrigerant exit 25 is comprised of an exit tube 45 and a fitting 50 that secures the subject device into the plumbing of the system. The exit fitting 50 is any suitable means that couples the subject device into the plumbing in the required position between the condenser CX' and the evaporator EX'.
Additionally, a second means for introducing a turbulent flow into the exiting liquefied refrigerant is mounted proximate the exit 25. A "turbulator" 60 is held in place by cooperation between the exit tube 45 and the exit fitting 50 or any other equivalent means. The turbulator is usually a separate component that is secured within the components of the exit from the vessel 1, however, the turbulator may be an integral part of the vessel 1 refrigerant exit. As clearly seen in FIGS. 5-7, the turbulator comprises a disk 62 with a central aperture 63 and at least one fixed angle blade 65 formed or cut into the disk 62. Preferably, a set of fixed angle blades 65 are provided to add turbulence to the exiting refrigerant (two blades 65 are depicted in the figures, but more than two blades 65 are possible).
The blades 65 are angled to induce rotational, turbulent motion of the liquid refrigerant and the refrigerant exits the vessel 1. Various angles for the blades 65 are suitable for generating the required turbulence.
Preferably, the subject vessel 1 is placed in the adapted system so that the refrigerant exit 25 is no lower than the lowest portion of the condenser CX'. Liquid refrigerant from the condenser CX' enters the vessel 1 and is directed into a swirling motion about the interior volume 3 by the delivery tube 35. The swirling liquid refrigerant leaves the vessel 1 by means of the refrigerant exit 25 and then encounters the turbulator 60. The blades 65 of the turbulator 60 add additional turbulence into the flow of the refrigerant.
The invention has now been explained with reference to specific embodiments. Other embodiments will be suggested to those of ordinary skill in the appropriate art upon review of the present specification.
Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be obvious that certain changes and modifications may be practiced within the scope of the appended claims. | For use with a heat exchange system having a compressor, condenser, evaporator, expansion device, and circulating refrigerant, an efficiency enhancing apparatus. Comprising the apparatus is a liquid refrigerant containing vessel having a refrigerant entrance and a refrigerant exit with the vessel positioned in the heat exchange system between the condenser and the evaporator. Included are means associated with said vessel for creating a turbulent flow of liquefied refrigerant. | 5 |
RELATED APPLICATION
This application is a continuation of U.S. patent application Ser. No. 08/104,343 filed Aug. 9, 1993, now U.S. Pat. No. 5,496,301 which is a continuation-in-part of U.S. patent application Ser. No. 08/021,507 filed Feb. 23, 1993, now U.S. Pat. No. 5,345,070 which is a continuation-in-part of U.S. patent application Ser. No. 07/952,951, filed Sep. 25, 1992 now abandoned. U.S. Ser. No. 08/104,343, U.S. Ser. No. 08/021,507 and U.S. Ser. No. 07/952,951 are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a device for sampling biological fluids during collection using a closed collection system. More particularly, the invention relates to a device for sampling blood or separated blood components during collection without "opening" the collection tubing system and thereby compromising the sterile fluid pathway or exposing the user to potentially contaminated blood or blood product.
BACKGROUND OF THE INVENTION
Various techniques are known in the art for withdrawing samples of biological fluids during collection. Sampling systems designed for blood sampling during blood donation include, for example, a blood sample bag preconnected to the blood donor line (U.S. Pat. No. 2,950,716) and a preconnected vacuum tube collector (ADAM Medical Products Ltd.; Ashdod, Israel). Both fluid sampling systems involve "opening" the collection tubing network tea removable sample container, however, and thus compromise the sterile fluid pathway. The potential for bacterial contamination of the collected product thus limits use of these direct sampling devices to the sampling of nonperishable fluids, i.e., fluids destined for immediate refrigeration or use.
Sampling techniques and devices designed for use with "closed" collection systems have also been proposed. As used herein, a "closed" collection system refers to a functionally closed fluid collection system sealed to ensure fluid sterility either by hermetically sealing the entire system or by providing sterile barrier filters at all connections to the collection system, U.S. Pat. No. 4,978,446 illustrates a functionally closed system employing a sterile barrier filter. Closed collection systems are typically used to collect biological fluids not destined for immediate transfusion or processing, or substances whose chemical or physical integrity is compromised by cooling. Sampling devices adapted for closed collection systems generally comprise a sample inlet tube positioned between the sample container and the fluid pathway, said inlet tube comprising a clamping means to seal off the sample reservoir from the sterile fluid pathway prior to withdrawing the sample.
Although these sampling devices have been successfully used to sample donor whole blood during blood and platelet collection, such devices are deficient in several respects. First, none of these systems assure a hermetic fluid-tight seal between the sample reservoir and the fluid pathway. The clamp mechanism can fail during operation causing leakage of contaminated fluid into the sterile fluid pathway, or the operator can inadvertently fail to seal off the fluid pathway from the sample reservoir prior to removing a sample. In either event, the collected product must be immediately processed or discarded. Second, removal of the sample reservoir requires cutting the sample inlet tube using a knife or scissors, a procedure which exposes the operator to contact with the fluid which may be infectious or otherwise hazardous. The use of the knife or scissors also increases the time required. The contaminated knife or scissors must be handled with care to avoid contact with the fluid, and must be cleaned or sterilized after each use. Third, after the sample reservoir is removed from the collection system, the fluid is transferred from the sample container into test tubes for analysis, a procedure which creates air-borne particles and splashing, again exposing the operator to potentially hazardous fluid. Alternatively, transfer to test tubes is accomplished using conventional hypodermic needles and syringes. Although this latter method minimizes fluid spillage, it generates used needles and the problems associated therewith, including disposal concerns and the risk of accidental punctures.
A need therefore exists for a device for removing biological fluid samples during collection without opening the collection tubing system and thereby compromising the sterile fluid pathway, and which also minimizes exposure to the potentially infectious or hazardous fluid during sample handling and processing.
SUMMARY OF THE INVENTION
The present invention provides a safe and efficient method for removing biological fluid samples during collection without opening the closed collection system, thereby impairing the sterility of the collected fluid. A sample bag adjoining the fluid collection reservoir is filled coincident with fluid collection, then hermetically sealed and physically separated from the fluid collection reservoir for analysis. The sealing and separation procedures are accomplished using a radio frequency tubing sealer as described in U.S. Pat. No. 5,345,070. In accordance with this aspect of the invention, an insulating sleeve is installed around the outside of the sample bag at the segment adjoining the fluid collection reservoir. The tubing sealer is then used to compress and heat the bag at the location of the insulating sleeve. The insulating sleeve causes the plastic in the bag to retain sufficient heat to both seal the bag, creating a hermetic fluid-tight seal between the sample bag and collection reservoir, and to create a thin, easily torn, web between the sealed bag and reservoir. A plurality of sample bags and insulating sleeves may be used to obtain multiple fluid samples.
Another significant aspect of the present invention is to provide a safe and efficient method for removing biological fluid samples during collection without opening the collection tubing system, thereby impairing the sterility of the fluid pathway. In accordance with this aspect of the invention, at least one sample tube connected to the sterile fluid pathway is filled, then hermetically sealed and physically separated from the fluid pathway using a radio frequency tubing sealer and insulating sleeve, as described above. In accordance with this aspect of the invention, a hermetic fluid-tight seal is created between the sample tube and sterile fluid pathway. A plurality of sample tubes may be used to obtain multiple samples either simultaneously or throughout the collection process.
Still another significant aspect of the present invention is to minimize exposure to the sample fluid during sample processing by incorporating a vacuum tube collection device, such as a Vacutainer™-brand holder available from Becton-Dickenson, into the sample bag. The vacuum tube collection device as used herein comprises a needle encapsulated within a resealable elastomeric sheath (e.g., latex or polyurethane) to prevent fluid leakage, and further comprises a cylindrical holder or shield around the enclosed needle to prevent accidental needle punctures. To withdraw a sample, an evacuated test tube comprising a penetrable septum, such as a Vacutainer™-brand collection tube, is inserted into the holder. The sample goes directly from collection to analysis, eliminating the open transfer step previously employed during sample preparation.
In a preferred embodiment, the fluid sampling device is used to sample donor whole blood and/or blood platelets during platelet collection, such as with the Spectra™ platelet collection system manufactured by the assignee of the present invention. Aseptic collection and sampling is especially important during platelet collection since the product requires maintenance at room temperature.
The exact nature of this invention as well as other features and advantages thereof will be readily apparent from consideration of the specification, including the drawing. Those of skill in the art will appreciate that the invention described herein is susceptible to many modifications and variations without departing from its scope as defined by the appended claims.
BRIEF DESCRIPTION OF THE DRAWING
The accompanying drawing illustrates preferred embodiments of the invention, wherein:
FIG. 1 is a perspective view of the fluid sampling device in an embodiment of the present invention.
FIG. 2 illustrates the use of a tubing sealer and an insulating sleeve to seal a sample bag and create a thin, easily tearable web in accordance with the present invention.
FIG. 3 illustrates an alternative embodiment of the fluid sampling device of the present invention.
FIG. 4 illustrates a second alternative embodiment of the fluid sampling device of the present invention.
FIG. 5 illustrates a vacuum tube collection device connected to the sample bag in accordance with the present invention.
FIG. 6 illustrates an alternative embodiment of the fluid sampling device of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, like numbers indicate like features and the same number appearing in more than one figure refers to the same element.
FIG. 1 illustrates a sample bag 1, with a thermal insulating sleeve 2 installed thereon, connected to a fluid collection reservoir 3 in the fluid sampling device of the present invention. The sample bag 1 and fluid collection reservoir 3 are formed of a flexible thermoplastic material having a relatively high dielectric loss coefficient so that it is excited and heated in the presence of a radio frequency (RF) electric field.
The thermal insulating sleeve 2 comprises a tube-like structure having a first end 4 and a second end 5 with an inside dimension or diameter sufficiently large that it will fit over the outside diameter of the sample bag 1. The insulating sleeve 2 thus surrounds and conforms to the shape of the sample bag 1. The insulating sleeve 2 is a flexible or semi-rigid cylindrical tube having a circular or oblong cross sectional configuration which conforms to the shape of the sample bag. It has been found that if the inside dimension of the thermal insulating sleeve 2 is sufficiently large to fit over the outside diameter of the sample bag 1, the actual inside dimension is not critical. The insulating sleeve 2 is formed of a material that has low dielectric loss coefficient so that it is not excited and heated in the presence of an RF electric field. The insulating sleeve has an insulation value and wall thickness selected to retain sufficient heat in the thermoplastic material of the sample bag 1 so that when the sample bag is welded to form a seal separating it from the fluid collection reservoir 3, a thin, easily tearable web is formed. The thin web facilitates physically separating the sample bag 1 and the fluid collection reservoir 3 from each other while maintaining fluid-tight seals on both the sample bag 1 and the collection reservoir 3.
In a preferred embodiment, the thermal sleeve 2 is formed from a segment of polypropylene tubing having an inside diameter of 0.208 inches and a wall thickness of between 0.0055 inches and 0.0070 inches. Polypropylene insulating sleeves 2 having wall thicknesses of 0.0050 and 0.0080 inches have also been successfully used. The insulating sleeve 2 is preferably installed on the sample bag 1 during the manufacture of the sample bag 1 and fluid collection reservoir 3 by slipping the insulating sleeve over the lower end of the sample bag.
The thermal insulating sleeve 2 may optionally (but preferably does not) have a slit 6 extending through the wall of the insulating sleeve and further extending from the first end 4 to the second end 5. The slit 6 may be longitudinally straight and parallel to an axis of the sleeve 2, or it may have a spiral configuration or a vee configuration. The slit 6 permits installing the insulating sleeve 2 at a desired sealing location along the sample bag 1 by deforming the plastic material of the insulating sleeve to spread the slit to a size at least as large as the outside diameter of the sample bag.
In an alternative embodiment not illustrated by the accompanying figures, the sample bag 1 is positioned near the top of the fluid collection reservoir 3 and projects upward with respect thereto.
FIG. 2 illustrates the use of an RF tubing sealer 7 and a thermal insulating sleeve 2 to seal a sample bag 1 and create a thin, easily tearable web in accordance with the present invention. The RF tubing sealer 7 may be of the type described in U.S. Pat. No. 4,013,860, issued Mar. 22, 1977 to Hosterman et al. for a "Hand Held Electro-Mechanism Sealer," and manufactured by Engineering and Research Associates, Inc., of Tucson, Ariz., as Sebra™ Model No. 2380. The sample bag 1 with the insulating sleeve 2 installed thereon is placed between an upper jaw 8 and a lower jaw 9 of the tubing sealer 7. The jaws are moved towards each other by a mechanism (not shown) of the tubing sealer 7 until they come into contact with the surface of the insulating sleeve 2. The jaws 8 and 9 are further moved towards each other, squeezing and flattening the sample bag 1 and the insulating sleeve 2. The jaws 8 and 9 compress the insulating sleeve 2 and sample bag 1 until the sample bag is squeezed tight, interrupting fluid communication between the sample bag 1 and the fluid collection reservoir 3. RF energy is applied to the upper jaw and lower jaw 8 and 9, respectively, to create an electric field between the upper jaw 8 and the lower jaw 9.
The electric field established by applying RF energy to the jaws 8 and 9 causes dielectric heating and resultant melting of the thermoplastic material of the sample bag 1. With the sides of the sample bag 1 contacting each other at the sealing location, the melting causes the sides to join and form a hermetic seal at the sealing location permanently preventing fluid communication between the sample bag 1 and the fluid collection reservoir 3. The sample bag 1 and the fluid collection reservoir 3 are physically joined by a thick web of thermoplastic material. With the insulating sleeve 2 in place, sufficient heat is retained in the thermoplastic material of the sample bag 1 so that further melting occurs at the sealing location as the jaws 8 and 9 are moved toward each other. This additional melting forms a thin, easily tearable web between the sample bag 1 and the fluid collection reservoir 3, leaving a hermetic seal on both the bag and the reservoir. The thin web may then be manually torn to physically separate the sample bag 1 from the fluid collection reservoir 3.
FIG. 3 illustrates an alternative preferred embodiment of the present invention. In this alternative preferred embodiment, a sample chamber 10, with an insulating sleeve 2 installed thereon, is removably connected to a fluid collection bag 11 by a perforated border 12. Following fluid collection, the fluid collection bag 11 is inverted causing fluid to enter the sample chamber 10 from the fluid collection bag 11 through an aperture 13. The sample chamber 10 is then hermetically sealed above the aperture 13 to prevent fluid communication between the sample chamber 10 and the fluid collection bag 11 using a radio frequency tubing sealer, as described above. The perforated border 12 is then manually torn to physically separate the sample chamber 10 from the fluid collection bag 11. As illustrated in FIG. 3, a plurality of sample chambers 10 and insulating sleeves 2 may be used to obtain multiple fluid samples. This alternative embodiment optionally includes a collection bag hanger 14 for hanging the collection bag 11, also as illustrated.
FIG. 4 illustrates yet another alternative embodiment of the present invention. In this alternative preferred embodiment, a sample tube 15, with an insulating sleeve 2 installed thereon, is connected at the proximal end to a fluid line 16. The sample tube 15 is a typical flexible thermoplastic medical tube. During sample collection, a clamping means 18 positioned near the proximal end of the sample tube 15 is opened, and trapped air escapes through a hydrophobic filter 17 enclosed within a plastic cap 19, positioned at the distal end of the sample tube 15. After sample collection, the clamping means 18 is closed and the sample tube 15 is hermetically sealed and separated from the fluid line 16 using a radio frequency tubing sealer, as described above. As illustrated in FIG. 4, a plurality of sample tubes 15 and insulating sleeves 2 may be used to obtain multiple fluid samples, either simultaneously or periodically throughout the collection process. The insulating sleeve 2 may be positioned above or below the clamping means 18 relative to the fluid line 16. Also as illustrated, this alternative embodiment optionally includes a sample port, such as a rubber septum 20, to remove test samples for analyses.
FIG. 5 illustrates a vacuum tube collection device, such as a Vacutainer™-brand collection tube and a Vacutainer™-brand holder, in combination with the sample bag 1 and tubular insulating sleeve 2 of the present invention. The vacuum tube holder 24 comprises a needle 21 encapsulated within a resealable elastomeric sheath 22 and a cylindrical plastic shield 23 to prevent fluid leakage and contact with the needle. The vacuum tube 26 is an evacuated tube closed by a septum, such as a Vacutainer™-brand collection tube. A Luer adapter 25 can be used to affix the Vacutainer™-brand holder 24 to the sample bag 1, as shown in FIG. 5. The Vacutainer™-brand tube 26 is inserted into the Vacutainer™-brand holder 24 to remove a test sample for analysis. A system such as shown in FIG. 5 retains the strict nature of a closed system while providing samples for laboratory analysis without the danger of inadvertent fluid spillage or needle sticks.
FIG. 6 illustrates an alternative embodiment of the present invention comprising a vacuum tube collection device in combination with the sample bag 1. The vacuum tube collection device is preferably a Vacutainer™-brand collection tube and a Vacutainer™-brand holder, as described above. In this alternative preferred embodiment, a sample inlet tube 15, with a clamping means 18 and an insulating sleeve 2 installed thereon, is connected at its proximal end to a fluid line 16 or a fluid collection receptacle such as receptacle 11 in FIG. 3. The sample bag 1 is connected to the vacuum tube collection device by a sample outlet tube 27. Both sample inlet tube 15 and a sample outlet tube 27 are typical flexible thermoplastic medical tubes. During sample collection, fluid flow into sample bag 1 is controlled using a clamping means 18. After sample collection, the clamping means 18 is closed and the sample tube 15 is optionally sealed and separated from the fluid line 16 using a radio frequency tubing sealer, as described above. To withdraw a sample for analysis, an evacuated collection tube 26, such as a Vacutainer™-brand collection tube, is inserted into the vacuum tube holder 24. The needle 21 then pierces the resealable elastomeric sheath 22 and the penetrable rubber septum 28, thus allowing fluid flow into the collection tube 26. If desired, an insulating sleeve 2, such as shown in FIG. 6, can be used to seal the sample bag 1 from the vacuum tube collection device after a sample has been withdrawn for analysis. Although the embodiment illustrated in FIG. 6 comprises an insulating sleeve 2 on each of the sample inlet tube 15 and the sample outlet tube 27, both insulating sleeves are optional. Moreover, the insulating sleeve 2 on sample tube 15 may be positioned either above or below the clamping means 18 relative to the sample bag 1.
In each of the embodiments of the present invention, one or more additional seals may be made with the radio frequency tubing sealer at locations separated from but closely adjacent to the insulating sleeve 2 to form two seals that have thick webs that are not easily tearable. Such seals would normally be made before making the seal at the insulating sleeve 2, in order to provide additional security against exposure to blood or blood products.
Obviously, many modifications and variations of the present invention are possible and will be evident to those of ordinary skill in the art. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced in ways other than as specifically described herein. | A method and device for sampling biological fluids during collection without opening the functionally closed collection system, thereby compromising the sterility of the collected fluid. A sample bag connected to a fluid line or collection reservoir is filled coincident with fluid collection, then hermetically sealed and physically separated from the collection system using a radio frequency tubing sealer. A vacuum tube collection device is attached to the sample bag to minimize exposure to the fluid during sample handling and processing. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
BACKGROUND OF INVENTION
[0001] 1. Technical Field
[0002] The invention relates to tools and methods of treatment of well-bores that are used, for example, in the exploration and production of oil and gas. The present invention is related to a device for delivering fluids into a geologic zone in a well. In a particular example, the device is used for hydraulic fracturing, including a method for delivering treatment fluids into a geologic zone in a well. In another example, water may be injected into a zone for the purpose of disposal.
[0003] 2. Discussion of the Background
SUMMARY OF SOME EXAMPLES OF THE INVENTION
[0004] In one example, a system is disclosed for selectively treating zones in a cased well-bore, the system including: a downhole tool, having a body, an inner bore therethrough, an inner surface of the body formed by the inner bore, and an outer surface; at least one treatment port disposed on the outer surface of the body; means for selectively isolating the inner bore from the outer surface, the means for selectively isolating the inner bore comprising a sliding sleeve disposed within the inner bore of the body; means for isolating, the means comprising an annular chamber between inner surface of the body and an outer surface of the sliding inner sleeve, the chamber in isolation from the inner bore and the outer surface; means for maintaining the inner sliding sleeve in an open position, the means for maintaining disposed within the annular chamber; and means for maintaining the inner sliding sleeve in a closed position.
[0005] In one example. the system further includes: means for holding the inner sliding sleeve in an open position, the means comprising a collet disposed around the outer surface of the inner sleeve; at least one finger on the collet shaped to engage the inner surface for holding the sleeve in an open position; and where the inner surface is shaped at a predetermined location for engagably receiving the collet.
[0006] In one example. the means for isolating the annular chamber includes: a first seal disposed in a fixed position on the inner surface of the body, the outer surface of the inner sliding sleeve being slidably disposed on the first seal, the first seal disposed in a position on the inner surface that is longitudinally proximate to a first end of the inner sliding sleeve when the inner sleeve is positioned in the open position; and a second seal disposed in a fixed position on the inner surface of the body, the outer surface of the inner sliding sleeve being slidably disposed on the second seal, the second seal disposed in a fixed position on the inner surface that is longitudinally proximate to a second end of the inner sliding sleeve when the inner sleeve is positioned in the closed position; and where the first seal and the second seal are disposed in longitudinal positions such that the annular chamber maintains isolation when the inner sleeve is positioned in either the open position or in the closed position.
[0007] In one example, the system further includes: a seal disposed in a fixed position on the inner surface of the assembly body, the outer surface of the inner sliding sleeve being slidably disposed on the third seal, wherein the third seal is disposed in a fixed position on the assembly body that is longitudinally proximate to the one (first) end of the inner sliding sleeve when the inner sleeve is positioned in the closed position.
[0008] In one example, the system further includes means for lubricating the sliding engagement of the outer surface of the inner sleeve with the inner surface of the body, the means for lubricating comprising lubricating ports disposed on the outer surface of the tool, forming an orifice bore to the inner bore of the body, disposed longitudinally between the first and third seals and isolated (not in fluid communication) from communication with the annular (locking) chamber.
[0009] In one example, a system is disclosed for selectively treating zones in a cased well-bore, the system including: a downhole tool, having a body, an inner bore therethrough, an inner surface of the body formed by the inner bore, and an outer surface; at least one treatment port disposed on the outer surface of the tool, providing fluid communication between the inner bore the outer surface; means for selectively isolating the inner bore from the outer surface, the means for selectively isolating the inner bore comprising a sliding sleeve disposed within the inner bore, the inner sliding sleeve positioned in a closed position or open position with respect to the at least one treatment port; means for maintaining the inner sliding sleeve in an open position, the means comprising a collet disposed around an outer surface of the inner sleeve; at least one finger on the collet shaped to engage the inner surface for maintaining the sleeve in an open position, the inner surface shaped at a predetermined location for engagably receiving the collet; and means for maintaining the inner sliding sleeve in a closed position.
[0010] In one example, a system is disclosed for selectively treating zones in a cased well-bore, the system including: a downhole tool, having a body, an inner bore therethrough, an inner surface of the body formed by the inner bore, and an outer surface; at least one treatment port disposed on the outer surface of the tool, providing fluid communication between the inner bore and the outer surface; means for selectively isolating the inner bore from the outer surface, the means for selectively isolating the inner bore comprising a sliding inner sleeve disposed within the inner bore, the inner sliding sleeve positioned in a closed position or open position with respect to the at least one treatment port;
[0011] means for maintaining the inner sliding sleeve in a closed position, the means comprising a first groove disposed on the outer surface of the inner sliding sleeve and a shear pin disposed radially through the assembly body into the inner bore, engagable to the first groove; means for holding the inner sliding sleeve in an open position, the means comprising: a compression spring disposed in an inner wall formed by the inner bore, and a locking pin urged against the compression spring and protruding into the inner bore, engagably received by a second groove disposed on the outer surface of the inner sleeve; and where the second groove is disposed longitudinally distal from the first groove, relative to the treatment port.
[0012] In one example, the system further includes a means for isolating, the means comprising an annular chamber between the inner surface of the body and the outer surface of the sliding inner sleeve, the chamber in isolation from the inner bore and the outer surface.
[0013] In one example, a system is disclosed for selectively treating zones in a cased well-bore, the system including: a downhole tool, having a body, an inner bore therethrough, an inner surface of the body formed by the inner bore, and an outer surface; at least one treatment port disposed on the outer surface of the tool, providing fluid communication between the inner bore the outer surface; means for selectively isolating the inner bore from the outer surface, the means for selectively isolating the inner bore comprising a sliding sleeve disposed within the inner bore, the inner sliding sleeve positioned in a closed position or open position with respect to the at least one treatment port; means for maintaining the inner sliding sleeve in an open position; means for maintaining the inner sliding sleeve in a closed position; and means for lubricating the sliding engagement of the outer surface of the inner sleeve with the inner surface of the body.
[0014] In one example, a system is disclosed for protecting treatment ports in a downhole treatment tool, the treatment tool having an outer surface and an inner bore, the inner bore in fluid communication with the outer surface through one or more treatment port orifices disposed on the outer surface of the treatment tool, the system including: a dissolvable treatment port cover disposed in the fluid communication path of the treatment port.
[0015] In one example, disclosed is a cover configured to dispose over a treatment port of a downhole treatment tool, the cover comprising a dissolvable material.
[0016] In one example, disclosed is a downhole treatment tool collet, the collet including a unitary hollow cylindrical member; one or more individual cantilevered beams having a first end and a second end, the first end of each cantilevered beam disposed on the cylindrical member in longitudinal orientation circumferentially about the axis of the cylindrical member; a compression surface and a locking surface disposed on the second end of each cantilevered beam, the compression surface and the locking surface protruding radially outward relative to the axis of the cylindrical member; and where each cantilevered beam is flexible in a radial direction relative to the axis of the cylindrical member and where each beam is configured to receive a predetermined stress due to an applied inward deflection. In one example, the locking surface is disposed at an angle less than perpendicular relative to the longitudinal axis in the direction of the first end of the beam. In one example, disclosed is a collet and receiving system including the disclosed collet and a retaining groove disposed on an inner surface of a treatment tool where each cantilevered beam includes a locking member disposed on the outer face of the cantilevered beam and where the shape of the retaining groove is matched to fitably receive the one or more cantilevered beams of the collet.
[0017] In one example, disclosed is a method for treatment of a well, the method including: locating a treatment tool in a well; setting an activation tool in the well; placing a treatment; unsetting the activation tool; and where the treatment tool includes: a body having an inner bore therethrough, an inner surface of the body formed by the inner bore, and an outer surface; at least one treatment port disposed on the outer surface of the tool, providing fluid communication between the inner bore the outer surface; means for selectively isolating the inner bore from the outer surface, the means for selectively isolating the inner bore comprising a sliding sleeve disposed within the inner bore, the inner sliding sleeve positioned in a closed position or open position with respect to the at least one treatment port; means for maintaining the inner sliding sleeve in an open position; and means for maintaining the inner sliding sleeve in a closed position.
[0018] In one example of the method, the treatment tool further includes a means for isolating, the means comprising an annular chamber between inner surface of the body and an outer surface of the sliding inner sleeve, the chamber in isolation from the inner bore and the outer surface. In one example, the annular chamber is a constant volume chamber when the inner sliding sleeve is in any position.
[0019] In one example, disclosed is a method for treatment of a well, the method including: locating a treatment tool in a well, the treatment tool having a treatment port and a cover over the treatment port; setting an activation tool in the well; placing a treatment, including applying pressure to rupture cover; unsetting the activation tool.
[0020] In one example, disclosed is a method for treatment of a well, the method including: locating a treatment tool in a well, the treatment tool having a treatment port and a dissolvable cover over the treatment port; setting an activation tool in the well; placing a dissolving fluid across the cover; placing a treatment; unsetting the activation tool.
[0021] In one example, disclosed is a method for treatment of a well, the method including: locating a treatment tool in a well; setting an activation tool in the well; placing a treatment; unsetting the activation tool; and where the treatment tool comprises: a body having an inner bore therethrough, an inner surface of the body formed by the inner bore, and an outer surface; at least one treatment port disposed on the outer surface of the tool, providing fluid communication between the inner bore the outer surface; means for selectively isolating the inner bore from the outer surface, the means for selectively isolating the inner bore comprising a sliding sleeve disposed within the inner bore, the inner sliding sleeve positioned in a closed position or open position with respect to the at least one treatment port; means for maintaining the inner sliding sleeve in an open position; means for maintaining the inner sliding sleeve in a closed position; means for isolating, the means comprising an annular chamber between inner surface of the body and an outer surface of the sliding inner sleeve, the chamber in isolation from the inner bore and the outer surface; and means for repeatably placing the inner sliding sleeve in an open or closed position, the means comprising a collet disposed around the outer surface of the sliding sleeve and a receiving groove disposed on the inner surface of the body. In one example, the annular chamber is a constant volume chamber when the inner sliding sleeve is in any position.
[0022] A system is disclosed for selectively treating zones in a cased well-bore, the system including: a downhole casing assembly housing, having an inner bore therethrough and an outer diameter; a plurality of treatment ports disposed on the outer surface of the assembly; means for selectively isolating the inner bore of the casing assembly from the outer diameter of the assembly, the means for selectively isolating the inner bore comprising a sliding inner pipe sleeve disposed within the inner bore of the assembly; a means for isolating including an annular chamber between the assembly and the sliding inner sleeve, the chamber in isolation from the inner bore of the pipe and the outer diameter of the housing; means for holding the inner sliding sleeve in an open position, the means for holding disposed within the annular chamber (locking chamber); and means for holding inner sliding sleeve in a closed position.
[0023] In one example of the invention, disclosed further are means for holding the inner sliding sleeve in an open position, the means comprising a collet ( 202 ) disposed around the outer surface of the inner sleeve; a plurality of fingers on the collet ( 501 ) shaped to engage the inner diameter wall/surface of the casing assembly housing/body for holding the sleeve in an open position, where the inner diameter wall/surface of the casing assembly/body is shaped at a predetermined location for engagably receiving the collet.
[0024] A system is disclosed for selectively treating zones in a cased well-bore, the system including: a downhole casing assembly housing, having an inner bore therethrough and an outer diameter; a plurality of treatment ports disposed on the outer surface of the assembly, providing fluid communication between the inner bore of the assembly and the outer diameter of the assembly housing; means for selectively isolating the inner bore of the casing assembly from the outer diameter of the assembly, the means for selectively isolating the inner bore comprising a sliding pipe sleeve ( 201 ) disposed within the inner bore of the assembly, the inner sliding sleeve positioned in a closed position or open position with respect to the treatment ports; means for holding the inner sliding sleeve in an open position, the means comprising a collet ( 202 ) disposed around the outer surface of the inner sleeve; a plurality of fingers on the collet ( 501 ) shaped to engage the inner diameter wall/surface of the casing assembly housing/body for holding the sleeve in an open position, the inner diameter wall/surface of the casing assembly shaped at a predetermined location for engagably receiving the collet; and means for holding inner sliding sleeve in a closed position.
[0025] In a further example, the means for holding in a closed position includes a plurality of shear pins disposed radially through the assembly housing into the inner bore, with engaging grooves disposed on the outer surface of the inner sleeve. In a further example, the means for holding in a closed position comprises a self-sealing shear pin.
[0026] A system is disclosed for selectively treating zones in a cased well-bore, the system including: a downhole casing assembly housing ( 1401 / 1402 ), having an inner bore therethrough and an outer diameter; a plurality of treatment ports disposed on the outer surface of the assembly, providing fluid communication between the inner bore of the assembly and the outer diameter of the assembly housing; means for selectively isolating the inner bore of the casing assembly from the outer diameter of the assembly, the means for selectively isolating the inner bore comprising a sliding pipe sleeve ( 1403 ) disposed within the inner bore of the assembly, the inner sliding sleeve positioned in a closed position or open position with respect to the treatment ports; means for holding the inner sliding sleeve in a closed position, the means comprising a locking pin shear (first) groove ( 1501 ) disposed on the outer surface of the inner sliding sleeve and a shear pin ( 1404 ) disposed radially through the assembly housing into the inner bore, engagable to the locking pin shear (first) groove ( 1501 ); means for holding the inner sliding sleeve in an open position, the means comprising a compression spring ( 1603 ) disposed within the inner wall/surface of the assembly housing/body, a locking pin ( 1601 ) urged against the compression spring and protruding into the inner bore of the assembly housing, engagably received by a locking (second) groove ( 1502 ) disposed on the outer surface of the inner sleeve. The locking groove is disposed longitudinally distal from the locking pin shear (first) groove, relative to the treatment port. In one example, compression spring ( 1603 ) is replaced by pressure provided from outside the assembly housing.
[0027] In one example of the invention, means for isolating the annular chamber includes a first seal disposed in a fixed position on the inner surface of the assembly, the outer surface of the inner sliding sleeve being slidably disposed on the first seal, the first seal disposed in a position on the assembly that is longitudinally proximate to one (first) end of the inner sliding sleeve when the inner sleeve is positioned in the open position; and a second seal disposed in a fixed position on the inner surface of the assembly, the outer surface of the inner sliding sleeve being slidably disposed on the second seal, the second seal disposed in a fixed position on the assembly that is longitudinally proximate to the other (second) end of the inner sliding sleeve when the inner sleeve is positioned in the closed position. The seals are disposed in longitudinal positions such that the annular chamber maintains isolation when the inner sleeve is positioned in either the open position or in the closed position.
[0028] In one example, the first seal comprises a lip seal disposed in an open-faced outward position with respect to the end of the inner sleeve.
[0029] In one example, the second seal comprises a lip seal disposed in an open-faced outward position with respect to the end of the inner sleeve.
[0030] In one example, the system further includes a (third) seal disposed in a fixed position on the inner surface of the assembly, the outer surface of the inner sliding sleeve being slidably disposed on the third seal, the third seal disposed in a fixed position on the assembly that is longitudinally proximate to the one (first) end of the inner sliding sleeve when the inner sleeve is positioned in the closed position. In a further example, the third seal is an energized seal ring. In one example, the treatment ports are positioned between the first and third seals.
[0031] In one example, the first seal comprises an energized seal ring.
[0032] In one example, the second seal comprises an energized seal ring.
[0033] In one example, the system includes a means for excluding debris existing outside the assembly housing from entering the treatment port. In one example, the means for excluding includes a cover disposed on the outer diameter of the assembly housing over the treatment port. In one example, the means for excluding includes a cover disposed in the fluid communication path of the treatment port. In one example, the cover is ruptured upon applying pressure from the inner bore of the assembly housing. In one example, the treatment port cover is comprised of a dissolvable material. In one example, the treatment port cover includes means for permeating dissolving solution to both sides of the cover. In one example, the treatment port cover includes one or more orifices. In one example, the means for permeating includes one or more orifices in the treatment cover.
[0034] In one example, the system includes means for lubricating the sliding engagement of the outer surface of the inner sleeve with the inner surface of the assembly housing. In one example, the means for lubricating includes lubricating ports disposed on the outer surface of the assembly housing, forming an orifice bore to the inner bore of the housing, disposed longitudinally between the first and third seals and isolated (not in fluid communication) from communication with the annular (locking) chamber. In one example, the lubricating ports include plugs.
[0035] In one example, a system is disclosed for protecting treatment ports in a downhole treatment tool, the treatment tool having an outer surface and an inner bore, the inner bore in fluid communication with the outer surface through one or more treatment port orifices disposed on the outer surface of the treatment tool, the system including a dissolvable treatment port cover disposed in the fluid communication path of the treatment port. In one example, the dissolvable cover is dissolvable by a corresponding dissolvent injected through the inner bore and through the treatment port. In one example, the treatment port cover includes means for permeating dissolving solution to both sides of the cover. In one example, the treatment port cover includes one or more orifices. In one example, the means for permeating includes one or more orifices in the treatment cover.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] In the following, preferred embodiments of the invention are depicted with reference to the accompanying Figures, in which:
[0037] FIG. 1 shows a 3-D perspective external view of the treatment valve assembly incorporating one example of the present invention;
[0038] FIG. 2A shows a cross-sectional view of the treatment valve assembly incorporating one example of the present invention in the closed valve position;
[0039] FIG. 2B shows a cross-sectional detail-view of the Treatment Port Seal Assembly;
[0040] FIG. 2C shows a cross-sectional detail-view of the Upper Chamber Seal Assembly;
[0041] FIG. 2D shows a cross-sectional detail-view of the Lower Chamber Seal Assembly;
[0042] FIG. 2E shows a cross-sectional detail-view of the Shear Screw in Housing;
[0043] FIG. 3 shows a cross-sectional view of the treatment valve assembly incorporating one example of the present invention in the open and locked position;
[0044] FIG. 4A shows a cut-away partial 3-D perspective view of, in one example, the exterior of the treatment valve assembly, detailing the Treatment Port, Treatment Port Recess and Treatment Port Cover prior to placement;
[0045] FIG. 4B shows a cut-away partial 3-D perspective view of, in one example, the exterior of the treatment valve assembly, detailing the Treatment Port Cover installed in the Treatment Port Recess, over the Treatment Valve;
[0046] FIG. 5A shows a 3-D perspective view of one example of the Collet used to lock the Treatment Valve, in the open position;
[0047] FIG. 5B shows a Cross-sectional view of one example of the Collet;
[0048] FIG. 5C shows a cut-away partial 3-D perspective detail-view of, in one example, the Collet Head;
[0049] FIG. 6A shows a 3-D perspective external view of one example of the Collet installed on the Inner Sleeve;
[0050] FIG. 6B shows a cross-sectional view of one example of the Collet installed on the Inner Sleeve;
[0051] FIG. 6C shows a cross-sectional detail-view of one example of threads affixing the Collet to the Inner Sleeve;
[0052] FIG. 6D shows a cross-sectional detail-view of one example of the Collet Head positioned over an Inner Sleeve Collet Relief Groove;
[0053] FIG. 6E -shows a cross-sectional detail-view of one example of the Inner Sleeve Landing Surface;
[0054] FIG. 7A shows a cross-sectional view of one example of the treatment assembly Housing member;
[0055] FIG. 7B shows a cross-sectional detail-view of one example of the Housing Locking Face;
[0056] FIG. 8A shows a cross-sectional view of one example of the treatment valve assembly in the closed position;
[0057] FIG. 8B shows a cross-sectional detail-view of one example of the Collet Head positioned in the Housing Collet Relief Groove;
[0058] FIG. 8C shows a cross-sectional view of one example of the treatment valve assembly in the open and locked position;
[0059] FIG. 8D shows a cross-sectional detail-view of one example of the Collet Head positioned with the Collet Locking Face engaged with the Housing Locking Face;
[0060] FIG. 9A shows a cross-sectional view of one example of the treatment valve assembly in the shouldered position;
[0061] FIG. 9B shows a cross-sectional detail-view of one example of the Collet Head positioned in the Housing in the shouldered position;
[0062] FIG. 9C shows a cross-sectional detail-view of one example of the Inner Sleeve Landing surface urged onto the Bottom Sub Landing Surface in the shouldered position;
[0063] FIG. 10A shows a partial cross-sectional view of one example of the treatment valve assembly in the closed position detailing the Lubricated Region;
[0064] FIG. 10B shows a cross-sectional detail-view of one example of the Treatment Port Seal Assembly;
[0065] FIG. 10C shows a cross-sectional detail-view of one example of the Upper Chamber Seal Assembly;
[0066] FIG. 10D shows a cross-sectional detail-view of one example of the Upper Lubrication Groove;
[0067] FIG. 10E shows a cross-sectional detail-view of one example of the Lower Lubrication Groove;
[0068] FIG. 11A shows a 3-D perspective view of one example of a multi-cycle Collet used to lock and unlock the Treatment Valve, to and from the open position;
[0069] FIG. 11B shows a Cross-sectional view of one example of the multi-cycle Collet;
[0070] FIG. 11C shows a cut-away partial 3-D perspective detail-view of, in one example, the multi-cycle Collet Head;
[0071] FIG. 12A shows a cross-sectional view of one example of the treatment valve assembly Housing for multi-cycle use;
[0072] FIG. 12B shows a cross-sectional detail-view of one example of multi-cycle Housing Open Retaining Face;
[0073] FIG. 13A shows a cross-sectional detail-view of one example of a multi-cycle treatment valve assembly with multi-cycle components in the shouldered position;
[0074] FIG. 13B shows a cross-sectional detail-view of one example of the Multi-Cycle Collet Head positioned in the Multi-Cycle Housing Collet Relief Groove;
[0075] FIG. 13C shows a cross-sectional detail-view of one example of a multi-cycle treatment valve assembly with multi-cycle components in the open and locked position;
[0076] FIG. 13D shows a cross-sectional detail-view of one example of the Multi-Cycle Collet Upper Compression Face engaged with the Multi-Cycle Housing Retaining Face;
[0077] FIG. 14A shows a cross-sectional view of one example of the treatment valve assembly configured to use locking pins;
[0078] FIG. 14B shows a cross-sectional detail-view of one example of the Treatment Port Seal Assembly;
[0079] FIG. 14C shows a cross-sectional detail-view of one example of the Upper Chamber Seal Assembly;
[0080] FIG. 14D shows a cross-sectional detail-view of one example of the Lower Chamber Seal Assembly;
[0081] FIG. 14E shows a cross-sectional detail-view of one example of the Locking Pin Mechanism;
[0082] FIG. 15A shows a 3-D perspective external view of one example of the Locking Pin Inner Sleeve;
[0083] FIG. 15B shows a cross-sectional view of one example of the Locking Pin Inner Sleeve;
[0084] FIG. 16A shows a 3-D perspective external view of one example of the Locking Pin;
[0085] FIG. 16B shows a 3-D perspective external view of one example of the Belleville Disc Spring; FIG. 16C shows a cross-sectional view of one example of the Belleville Disc Spring;
[0086] FIG. 16D shows a cross-sectional view of one example of the Locking Spring Stack;
[0087] FIG. 17A shows a cross-sectional view of one example of the treatment valve assembly configured to use locking pins, shown in the closed position;
[0088] FIG. 17B shows a cross-sectional detail-view of one example of the Locking Mechanism in the closed position;
[0089] FIG. 18A shows a cross-sectional view of one example of the treatment valve assembly configured to use locking pins, shown in the open and locked position;
[0090] FIG. 18B shows a cross-sectional detail-view of one example of the Locking Mechanism in the open and locked position;
[0091] FIG. 18C shows a cross-sectional detail-view of one example of a shoulder stop surface, shouldering Locking Pin Inner Sleeve in Locking Pin Bottom Sub;
[0092] FIG. 19 shows a flowchart describing an example of the method of operation of the Treatment Valve.
DETAILED DESCRIPTION
[0093] FIG. 1 shows a 3-D perspective external view of the treatment valve assembly incorporating one example of the present invention. FIG. 1 is an external view of the Treatment Valve 100 , and shows, in one example, its three major external components. A Ported Top Sub 101 is attached to a Bottom Sub 103 by a Housing member 102 . In this example, these components form the tool body. In one example, these parts making up the body of the tool are secured together with threaded connections. Treatment Valve 100 is deployed into the wellbore by placing it in-line with a production string. In one example, this is done by threading Bottom Sub 103 of assembled Treatment Valve 100 into the production string as it is deployed into the wellbore, then threading the production string into Ported Top Sub 101 , and continuing to deploy the production string into the wellbore.
[0094] An Inner Sleeve 201 (as shown in FIG. 2A ) is radially disposed inside Treatment Valve 100 and held in place by Shear Screws 104 which are inserted through and secured to Housing member 102 . Shear Screws 104 are used to maintain the position of Inner Sleeve 201 until Treatment Valve 100 is opened. Treatment Port(s) 208 are used to communicate fluids from the inside of the Treatment Valve 100 to the outside, similar in function to perforations that are placed in production strings with explosive charges. In one example, Treatment Port(s) 208 are oval in shape, and in that example the length and width of the Treatment Port 208 determine the flow area and velocity profile of the treatment fluid placed through the Treatment Port(s) 208 . In one example, the size and shape of Treatment Port(s) 208 and the number of Treatment Ports 208 are selected to optimize the placement of the treatment fluid into the formation(s). Each formation encountered has unique properties, which may require the size and shape of the Treatment Port(s) 208 to be adjusted to facilitate placing the desired treatment. In one example, Lubrication Ports/Plugs 105 are used to provide lubrication to the actuating parts of the Treatment Valve to increase the reliability of the assembly.
[0095] FIG. 2A shows a cross-sectional view of the treatment valve assembly incorporating one example of the present invention in the closed valve position. FIG. 2A is a cross-sectional view of the assembled Treatment Valve 100 in the closed position (denoted as Treatment Valve 200 ), as it is run into the wellbore. An Inner Sleeve 201 , runs the length of the Treatment Valve 200 from the Treatment Port Seal Assembly as shown in FIG. 2B , to the Lower Chamber Seal Assembly as shown in FIG. 2D . In one example, Inner Sleeve 201 serves two functions in this position. First, it isolates the inside of Treatment Valve 200 from the outside of the Treatment Valve 200 by isolating Treatment Port 208 . Second, it is the inner member that forms the inner wall of the Locking Chamber, 299 . A Collet 202 is radially disposed on the outside of the Inner Sleeve 201 and, in one example, is used to maintain the Treatment Valve in the open position. Examples of Collet 202 , and its function are further detailed in FIGS. 5A-C , 6 A-E, 8 A-D, 9 A-D. Orings 203 are placed to seal the threaded connection at the Ported Top Sub 101 and Housing 102 and the threaded connection at Housing 102 and Bottom Sub 103 . In one example, a Locator Groove 211 is placed radially inward in Bottom Sub 103 , located longitudinally near the bottom of the sub, and, in one example, is used to provide a means of locating the sleeve. A mechanical collar locator is known in the art as a means of locating upsets in wellbore tubulars, and can be used to locate the treatment valve assembly (the tool) by catching in Locator Groove 211 .
[0096] FIG. 2B shows a cross-sectional detail-view of the Treatment Port Seal
[0097] Assembly. FIG. 2B shows the Treatment Port Seal Assembly which is radially disposed of inwardly in Ported Top Sub 101 , located longitudinally above the Treatment Port 208 and is comprised of an Energizing Ring, 204 and a Seal Ring 205 which seals on Inner Sleeve 201 . In one example, Energizer Ring 204 is a Viton oring and Seal Ring 205 is a carbon filled Teflon ring. This seal assembly is capable of holding pressure in both directions, which is to say that it will maintain the isolation of the inside and outside of the Treatment Valve 100 , regardless of which pressure is higher. In one example, Seal Ring 205 seals on the outside diameter of Inner Sleeve 201 and is well-suited for this application because it will not roll or be pulled out of the seal groove when pressure is applied and when Inner Sleeve 201 is shifted downward. In one example, Seal Ring 205 provides the required seal by being forced onto Inner Sleeve 201 . Due to practical limitations in machining, Energizer Ring 204 is used to provide the force to engage the seal properly. In typical oring seals, the oring is compressed, which forces it onto the two parts being sealed; however, typical oring seals are known to roll in the groove and/or pull out of the groove when a part is moved under pressure. In a preferred embodiment, two individual seals, Seal Ring 205 and Energizer Ring 204 , combine into the seal assembly (shown in FIG. 2B ) to yield a seal that is much better suited to the application of the Treatment Valve 100 .
[0098] FIG. 2C shows a cross-sectional detail-view of the Upper Chamber Seal Assembly. FIG. 2C shows the Upper Chamber Seal Assembly which is radially disposed of inwardly with the open face of the seal oriented upward in Ported Top Sub 101 , located longitudinally below the Treatment Port 208 , and is comprised of a Lip Seal 206 and a Backup Ring, 207 . In one example, Lip Seal 206 is a Viton seal and Backup Ring 207 is a Moly Glass Teflon Ring. In one example, Lip Seal 206 seals on Inner Sleeve 201 and is capable of holding pressure in only one direction. In examples, lip seals are available in a variety of configurations and offered under a variety of commercial names, such as, lip seals and U cup seals. A predominate, defining characteristic of this type of seal is an open face elastomeric feature that is oriented towards the applied pressure. In examples, an energizer is placed in the open face to force the lip onto the part being sealed. Example energizers include springs, orings and X rings. Backup Ring 207 is placed on the low pressure side of the seal, and, in one example, is used to provide additional support to Lip Seal 206 , increasing the working pressure of the seal. Elastomeric seals are susceptible to extrusion, which is to say they push out into the gap between the parts being sealed. A seal will not hold the applied pressure and/or will interfere with the movement of the parts of the assembly when the seal extrudes through a gap to a point where it no longer is compressed onto the parts or is pulled out of the seal groove when the sealing parts are moved. Implementing a backup ring, for example Backup Ring 207 , provides additional support for the elastomeric seal by limiting the gap between the parts being sealed. In one preferred example, the lip seal configuration is particularly suited for this application because it is a pressure energized design, meaning that applied pressure to the open face acts to further engage Lip Seal 206 on Inner Sleeve 201 . In this example, a primary function of the seal is to isolate Locking Chamber 299 from the external wellbore pressure on the outside of Treatment Valve 100 .
[0099] FIG. 2D shows a cross-sectional detail-view of the Lower Chamber Seal Assembly. In one example, the Lower Chamber Seal is radially disposed of inwardly with the open face of the seal oriented downward in the Bottom Sub 103 and located longitudinally near the top of the Bottom Sub 103 where it will engage Inner Sleeve 201 while Treatment Valve 100 is in the closed position 200 . In one example, the Lower Chamber Seal is comprised of the same components as the Upper Chamber Seal for the same functionality.
[0100] FIG. 2E shows a cross-sectional detail-view of the Shear Screw in Housing. FIG. 2E shows Shear Screw 104 engaged in both Housing member 102 and Inner Sleeve 201 . In one example, Shear Screw 104 is placed radially on the exterior of Housing member 102 and is located longitudinally near the top where it can engage a Shear Screw Groove 601 of the Inner Sleeve 201 . Shear Screw 104 is used to maintain Inner Sleeve 201 in the closed position until a predetermined downward force is applied to Inner Sleeve 201 , thus shearing the screws and allowing relative movement of Inner Sleeve 201 inside Treatment Valve 100 . Shear Screw(s) 104 used, in one example, are self sealing. In one example, an Oring Seal 210 is affixed to Shear Screw 104 , in a groove, and provides isolation in both directions. In one example, Oring Seal 210 in made of Viton. It is important to note that in one preferred example, the seal is maintained even after the screw itself is sheared during operation.
[0101] In one example, Locking Chamber 299 is an annular region of the tool where features related to retaining Treatment Valve 100 in the desired closed and locked positions are located. In one example of Treatment Valve 100 , the Locking Chamber 299 is sealed from all wellbore fluids and associated debris to ensure that the locking features remain free of debris to enhance the reliability of operation. In one example, Locking Chamber 299 is constructed such that it is a constant-volume chamber, meaning that the volume of the chamber does not change when Treatment Valve 100 (inner sliding sleeve 201 ) is moved through its various positions. In one example, Locking Chamber 299 is defined by four major components: Ported Top Sub 101 , Housing member 102 , Bottom Sub 103 , and Inner Sleeve 201 . The exterior surface of Inner Sleeve 201 defines an inner wall of the annular area and the combination of the interior surface walls of Ported Top Sub 101 , Housing member 102 , and Bottom Sub 103 define an outer wall of the annular area. The annular region is sealed on the up-hole end by the Upper Chamber Seal Assembly, as shown in FIG. 2C , and the Oring 203 at the threaded connection of Ported Top Sub 101 and Housing member 102 . The down-hole end of Locking Chamber 299 is sealed by the Lower Chamber Seal, as shown in FIG. 2D , and the other Oring 203 at the threaded connection of Housing member 102 and Bottom Sub 103 . In one example, the final seal(s) isolating Locking Chamber 299 include an Oring Seal 210 , located on Shear Screw(s) 104 .
[0102] In one example of Treatment Valve 100 , this chamber is an atmospheric chamber, meaning that the pressure in Locking Chamber 299 is maintained at the atmospheric pressure when the tool was assembled. This can result in particularly high pressure differentials across the Upper and Lower Chamber Seals, as shown in FIGS. 2C and 2D . Consequently, the pressure energized design of Lip Seal 206 utilized in the Upper and Lower Chamber Seals, as shown in FIGS. 2C and 2D , is considered to greatly improve the overall reliability of Treatment Valve 100 .
[0103] FIG. 3 shows a cross-sectional view of the treatment valve assembly (the tool) incorporating one example of the present invention in the open and locked position. In one example, the FIG. 3 cross-sectional view of the assembled Treatment Valve 100 , in the open and locked position 300 , is the final position of Treatment Valve 100 after being actuated and the treatment placed. This position is attained by applying a downward force to Inner Sleeve 201 which is sufficient to shear Shear Screw(s) 104 . Once Shear Screw(s) 104 are sheared, Inner Sleeve 201 moves down and disengages the Treatment Port Seal Assembly, as shown in FIG. 2B , exposing Treatment Ports 208 . Treatment Ports 208 are exposed to provide fluid access to the reservoir behind the production string, and communicate the inside of the production string to the fluids in the reservoir. This communication enables both placing the treatment and producing the reservoir.
[0104] FIG. 4A shows a cut-away partial 3-D perspective view of, in one example, the exterior of the treatment valve assembly, detailing the Treatment Port, Treatment Port Recess and Treatment Port Cover prior to placement. FIG. 4A shows a detailed view of Treatment Port 208 and Treatment Port Cover 402 , which is used to shield Treatment port 208 from debris while being run in the wellbore and maintaining the lubrication of the valve. Also shown in FIG. 2A is a Treatment Port Recess 401 in which Treatment Port Cover 402 is placed.
[0105] FIG. 4B shows a cut-away partial 3-D perspective view of, in one example, the exterior of the treatment valve assembly (the tool), detailing the Treatment Port Cover installed in the Treatment Port Recess, over the Treatment Valve. FIG. 4B shows Treatment Port Cover 402 placed in Treatment Port Recess 401 . In one example, Treatment Port Cover 402 is adhered to Treatment Port Recess 401 by a suitable adhesive or solder. While being run in the wellbore, Treatment Valve 100 will be in contact with the wellbore or other tubular walls in both a sliding and rotating motion; therefore, in one example, Treatment Port Recess 401 is important because it protects Treatment Port Cover 402 from being pulled off Treatment Valve 100 due to contact with the wellbore or other tubulars in which it is conveyed through. In one example, the treatment port cover thickness and material combination provide a limited strength that can be ruptured by applying pressure from fluids pumped from the inner bore. In a preferred example, Treatment Port Cover 402 is constructed from a material that is dissolvable by a fluid that is compatible with the formation. In one example, the dissolvable fluid is selected from those fluids that are capable of dissolving the cover and yet are non-damaging to the wellbore formation of interest. In one example, the dissolving fluid is 15% Hydrochloric Acid. In one example, the treatment port cover thickness and material combination provide a limited strength that can be ruptured, after applying the dissolving fluid, by applying pressure from fluids pumped from the inner bore. In one example, Treatment Port Cover 402 is constructed of aluminum and, in further example, is 0.007 inch thick with, in further example, two 1/16 inch holes placed on the centerline. In one example, the holes placed in Treatment Port Cover 402 facilitate contact of the dissolving fluid with Treatment Port Cover 402 , in one example, by preventing a dead volume. In one example, Treatment Port Cover 402 is constructed, positioned, and arranged to keep debris out of the valve actuation area. In one example, Treatment Port Cover 402 is constructed, positioned, and arranged to maintain the lubrication placed in Treatment Valve 100 , at surface, which is introduced through Lubrication Port/Plug(s) 105 .
[0106] FIG. 5A shows a 3-D perspective view of one example of the Collet used to lock the Treatment Valve in the open position. FIG. 5A is an overall view of Collet 202 which is used to lock Treatment Valve 100 in the open position 300 . In one example, Collet 202 is a cylindrical component that is constructed to create individual Collet Fingers 501 which, in one example, is comprised of sixteen individual Collet Fingers 501 , in one example, disposed in longitudinal orientation circumferentially about the axis of the collet.
[0107] In one example, Collet 202 is a hollow cylindrical member. In one example, Collet 202 is a unitary cylindrical member. Collet 202 is shaped, positioned, and arranged to allow it to slide through Housing member 102 , which, in one example, has a smaller inside diameter than the outside diameter of Collet 202 . In one example, this is accomplished by machining individual Collet Fingers 501 , which can be viewed as individual cantilevered beams that will deflect under load. This deflection allows Collet Finger 501 to deflect inward and pass through a smaller diameter restriction of Housing 102 and spring back to the original outside diameter past the restriction. In one example, an additional feature of Collet 202 is that is can support longitudinal loads once engaged in a suitable retaining groove.
[0108] In one example, the length, width and thickness of Collet Fingers 501 are selected to match its operational requirements, as these parameters determine the stress induced in individual Collet Fingers 501 when deflected inward while shifting the Treatment Valve 100 . The combination of those characteristics and the yield strength of the material used to construct Collet 202 are selected to ensure that Collet Finger 501 is flexible enough to spring back after being compressed, which is to say that the stress due to the applied inward deflection does not exceed the yield strength of the material used to construct Collet 202 . In one example, Collet Finger 501 is of substantial enough strength to withstand the longitudinal loads applied during operation.
[0109] FIG. 5B shows a Cross-sectional view of one example of the Collet.
[0110] FIG. 5B shows the Collet Thread 502 , used to fix Collet, 202 to Inner Sleeve 201 at Inner Sleeve Thread 602 .
[0111] FIG. 5C shows a cut-away partial 3-D perspective detail-view of, in one example, the Collet Head 503 . A Collet Compression Face 504 is used to compress the collet in the downward movement by contacting Housing Compression Face 702 . In one example, Compression Face 504 is a surface on the free end of the cantilevered beam (finger), the compression surface forming part of the head that protrudes radially outward relative to the axis of the collet. Collet Locking Face 505 is machined to match a Housing Locking Face 703 in Housing member 102 , preventing Treatment Valve 100 from closing after being opened. In one example, Locking Face 505 is a surface on the free end of the cantilevered beam (finger), the locking surface forming part of the head that protrudes radially outward relative to the axis of the collet. In one example, the locking surface is disposed with a negative rake, for example, disposed at an angle less than 90 degrees from the longitudinal axis and in the direction of the first end of the beam, as illustrated in FIG. 5C . In one example, Collet Locking Face 505 has an angle of 30 degrees, for example, 30 degrees from the longitudinal axis and in the direction of the first end of the beam. In one example, to simplify machining, Collet Locking Face 505 has an angle of 35 degree, for example, 35 degrees from the longitudinal axis and in the direction of the first end of the beam.
[0112] In one example, the term collet refers to the physical appearance of the member, but does not necessarily require the collet member to squeeze the inner sleeve for secure holding. Rather, in one example, the collet member is secured to the inner sleeve by other means, such as threads, and the collet member functions to provide outwardly expanding fingers to urge stops, or locking faces, outward towards the inner surface wall of the assembly housing or body. The fingers are compressible radially inwards, allowing locking faces to be longitudinally inserted in position, longitudinally past diameter restrictions on the inner face of the assembly housing/body.
[0113] FIG. 6A shows a 3-D perspective external view of one example of the Collet installed on the Inner Sleeve. Collet 202 is shown installed on Inner Sleeve 201 . Collet 202 is placed radially on Inner Sleeve 201 , longitudinally located on an Inner Sleeve Thread 602 , with Collet Head(s) 503 oriented downward from Threads 502 and 602 .
[0114] FIG. 6B shows a cross-sectional view of one example of the installed on the Inner Sleeve. Collet 202 is shown installed on Inner Sleeve 201 . A Shear Screw Groove 601 is a groove radially placed on Inner Sleeve 201 , placed longitudinally such that Shear Screws 104 , inserted and retained in Housing 102 , can be engaged.
[0115] FIG. 6C shows a cross-sectional detail-view of one example of threads affixing the Collet to the Inner Sleeve. Threads 502 and 602 , as shown are used to affix Collet 202 to Inner Sleeve 201 .
[0116] FIG. 6D shows a cross-sectional detail-view of one example of the Collet Head positioned over an Inner Sleeve Collet Relief Groove. Collet Head 503 , as shown, is located on Inner Sleeve 201 . The Inner Sleeve Collet Relief Groove 603 is a small relief placed on the exterior of Inner Sleeve 201 to allow for proper deflection of Collet Head 503 as it is compressed while moving longitudinally through Housing 102 , such that Collet Head 503 does not contact Inner Sleeve 201 as the Treatment Valve 100 is moved from the closed position.
[0117] FIG. 6E -shows a cross-sectional detail-view of one example of the Inner Sleeve Landing Surface. An Inner Sleeve Landing Surface 604 is shown on Inner Sleeve 201 , in one example, is used to limit the movement of Inner Sleeve 201 within Treatment Valve 100 . Inner Sleeve Landing Surface 604 will come in contact with the Bottom Sub Landing Surface 901 . In one example, Inner Sleeve Landing Surface 604 forms a contact shoulder against Bottom Sub Landing Surface 901 to limit further longitudinal movement of Inner Sleeve 201 .
[0118] FIG. 7A shows a cross-sectional view of one example of the treatment assembly Housing member. Housing member 102 is shown with detail of a Housing Collet Relief Groove 701 , which is a groove placed into Housing member 102 , allowing Collet Finger(s) 501 (as shown in FIG. 5A ) to be in a non-stressed state while Treatment Valve 100 is in the closed position 200 . In one example, the placement of Collet Head 503 in Housing Collet Relief Groove 701 is shown in FIG. 8B . A Housing Collet Compression Face 702 is shown, which acts on Collet Compression Face 504 (as shown in FIG. 5C ) to bend Collet Finger(s) 501 (not shown) as the Treatment Valve, 100 , is moved from the closed position, 200 .
[0119] FIG. 7B shows a cross-sectional detail-view of one example of the Housing Locking Face. A Housing Locking Face 703 is matched to Collet Locking Face 505 (shown in FIG. 5C ) to prevent Treatment Valve 100 from closing after actuation. The interaction of the two locking faces are further discussed using FIGS. 8D and 9B .
[0120] FIG. 8A shows a cross-sectional view of one example of the treatment valve assembly in the closed position. Treatment Valve 100 in the closed position 200 is included to show the location of Collet Head 502 relative to the treatment valve assembly in the closed position 200 .
[0121] FIG. 8B shows a cross-sectional detail-view of one example of the Collet Head positioned in the Housing Collet Relief Groove. Collet Head 503 is shown disposed in Housing Collet Relief Groove 701 , when Treatment Valve 100 is in the closed position, 200 . This relief groove allows the Collet to be placed in the assembly without stressing the Collet Finger(s) 501 . As Treatment Valve 100 is moved from the closed position 200 , Collet Compression Face 504 contacts Housing Compression Face 702 , forcing Collet Finger(s), 501 to deflect radially inward.
[0122] FIG. 8C shows a cross-sectional view of one example of the treatment valve assembly in the open and locked position. Treatment Valve 100 , in the open and locked position 300 , is included to show the location of Collet Head 503 relative to the treatment valve assembly in the open and locked position, 300 .
[0123] FIG. 8D shows a cross-sectional detail-view of one example of the Collet Head positioned with the Collet Locking Face engaged with the Housing Locking Face. Collet Head 503 is shown disposed in Housing member 102 , when the Treatment Valve 100 is in the open and locked position 300 . Collet Locking Face 505 is in contact with Housing Locking Face 703 . These two faces are in contact and, in one example, the 30 degree angle at which they are placed in the assembly prevent the Treatment Valve 100 from closing. An upward force placed on the Inner Sleeve 201 is transmitted to Collet 202 by the thread engagement at Collet Threads 502 and Seal Threads 602 . This force is further transmitted through Collet Finger 501 , and then to Housing member 102 by the engagement of Collet Locking Face 505 and Housing Locking Face 703 , thus preventing Treatment Valve 100 from closing. The angle of the locking faces act to lock Treatment Valve 100 by preventing Collet Finger(s) 501 from deflecting inward when an upward force is applied to Inner Sleeve 203 .
[0124] FIG. 9A shows a cross-sectional view of one example of the treatment valve assembly in the shouldered position. Treatment Valve 100 , in the shouldered position 900 , is included to show the location of Collet Head 503 relative to the treatment value assembly in the shouldered position 900 . In one example, shouldered position 900 is defined by the contact of Inner Sleeve 201 and Bottom Sub 103 , which prevents any further movement in the downward direction. Shouldered is meant to describe an arrangement where the two parts are touching but are not locked together.
[0125] FIG. 9B shows a cross-sectional detail-view of one example of the Collet Head positioned in the Housing in the shouldered position. Collet Head 503 is shown disposed in Housing member 102 when the Treatment Valve 100 is in the shouldered position, 900 . A Collet-Bottom Sub Gap 801 is formed by the space between Collet Head 503 and Bottom Sub 103 . The shouldered position 900 is achieved when Inner Sleeve 201 comes in contact with Bottom Sub 103 and prevents further downward movement of Inner Sleeve 201 in Treatment Valve, 100 . This position is important because, in one example, Collet Finger(s) 501 are slender items that cannot support significant longitudinal compression loading. If Collet Finger(s) 501 were to be loaded in compression longitudinally it is likely they would buckle and preventing Collet Locking Face 505 from engaging Housing Locking Face 703 and/or damage Collet Finger(s) 501 , preventing them from being able to support an upward load applied to Inner Sleeve 201 . If either of these two conditions existed, the Treatment Valve 100 could close after opening.
[0126] FIG. 9C shows a cross-sectional detail-view of one example of the Inner Sleeve Landing surface urged onto the Bottom Sub Landing Surface in the shouldered position. In one example, Inner Sleeve 201 shoulders onto Bottom Sub 103 . The engagement occurs at an Inner Sleeve Shouldering Face 604 and a Bottom Sub Shouldering Face 901 . The interaction of these two faces achieves the shouldered position 900 of Treatment Valve 100 and prevents any compression loading and subsequent damage of Collet Finger(s) 501 (not shown). In one example, the shouldered faces are placed at 60 degree angles.
[0127] FIG. 10A shows a partial cross-sectional view of one example of the treatment valve assembly in the closed position detailing the Lubricated Region. In one example, a Lubricated Region 1001 is an annular region defined by the exterior surface of Inner Sleeve 201 and the interior surface of Ported Top Sub 101 , between the Treatment Port Seal Assembly shown in FIG. 10A and the Upper Chamber Seal Assembly shown in FIG. 10B .
[0128] FIG. 10B shows a cross-sectional detail-view of one example of the Treatment Port Seal Assembly. FIG. 10B is a detail view of the Treatment Port Seal Assembly, which, in this example, is identical to FIG. 2B , and is included here to describe the upper boundary of Lubricated Region 1001 .
[0129] FIG. 10C shows a cross-sectional detail-view of one example of the Upper Chamber Seal Assembly. FIG. 10C is a detail view of the Upper Chamber Seal Assembly, which, in this example, is identical to FIG. 2C , and is included here to describe the lower boundary of Lubricated Region 1001 .
[0130] FIG. 10D shows a cross-sectional detail-view of one example of the Upper Lubrication Groove. In one example, an Upper Lubrication Groove 1002 is placed radially around the inside diameter of Ported Top Sub 101 and is located longitudinally below the Treatment Port Seal Assembly as shown in FIG. 10B , and longitudinally above Treatment Port 208 . In one example, Upper Lubrication Groove 1002 provides a low resistance channel for a lubricant that is to be introduced around the entire circumference of the Inner Sleeve. In one example, the lubricant is grease that does not cause damage to the formation or interact in the treatment fluid in a manner that causes a change to the fluid properties that would prevent a successful treatment. In one example, the lubricant is introduced to the lubrication groove, and subsequently the valve, through one or more of Lubrication Ports 105 . In one example, after the lubricant is introduced via Lubrication Port 105 , the port is sealed with a cap or plug. In one example, the lubricant is formulated to operate as a debris barrier. An added benefit of the lubrication acting as a barrier is that it prevents debris from entering this area of Treatment Valve 100 and, when used in conjunction with Treatment Port Cover 402 , ensures that the lubricant remains in place and fully prevents large debris from fouling Treatment Valve 100 .
[0131] FIG. 10E shows a cross-sectional detail-view of one example of the Lower Lubrication Groove. In one example, a Lower Lubrication Groove 1003 is placed radially around the inside diameter of Ported Top Sub 101 and is located longitudinally above the Upper Chamber Seal Assembly as shown in FIG. 10C , and longitudinally below Treatment Port 208 . In one example, the function of Lower Lubrication Groove 1003 is equivalent to that of Upper Lubrication Groove 1002 , as described with FIG. 10D .
[0132] FIG. 11A shows a 3-D perspective view of one example of a multi-cycle Collet used to lock and unlock the Treatment Valve, to and from the open position. In one example, a Multi-Cycle Collet 1101 is matched with a compatible Multi-Cycle Housing 1201 , allowing Treatment Valve 100 to be placed selectively into the open and closed positions a number of times. In one example, Multi-Cycle Collet 1101 is a cylindrical component constructed to create individual Collet Fingers 1102 which, in one example, is comprised of sixteen individual Collet Fingers 1102 . In one example, Multi-Cycle Collet 1101 is shaped, positioned, and arranged to allow it to slide through Multi-Cycle Housing 1201 , which has a smaller inside diameter than the outside diameter of Multi-Cycle Collet 1101 . This is accomplished by machining individual Collet Fingers 1102 , which can be viewed as individual cantilevered beams that will deflect under load. This deflection allows Collet Finger 1102 to deflect inward and pass through a smaller diameter of Multi-Cycle Housing 1201 and spring back to the original outside diameter. In one example, an additional feature of Multi-Cycle Collet 110 is that its composition, shape, position, and arrangement of fingers are designed to support longitudinal loads once engaged in a suitable retaining groove.
[0133] In one example, the length, width and thickness of Collet Finger 1102 are selected to match its operational requirements, as these parameters determine the stress induced in individual Collet Fingers 1102 when deflected inward while shifting the Treatment Valve 100 . The combination of those characteristics and the yield strength of the material used to construct Multi-Cycle Collet 1101 are selected to ensure that Collet Finger 1102 is flexible enough to spring back after being compressed, which is to say that the stress due to the applied inward deflection does not exceed the yield strength of the material used to construct Multi-Cycle Collet 1101 . In one example, Collet Finger 1102 is of substantial enough strength to withstand the longitudinal loads applied during operation.
[0134] FIG. 11B shows a Cross-sectional view of one example of the multi-cycle Collet. In one example, a Collet Thread 1103 is used to fix Multi-Cycle Collet 1101 to Inner Sleeve 201 (not shown).
[0135] FIG. 11C shows a cut-away partial 3-D perspective detail-view of, in one example, the multi-cycle Collet Head. A Multi-Cycle Collet Head 1104 is disposed on Multi-Cycle Collet 1101 . In one example, a Lower Collet Compression Face 1105 is disposed on Multi-Cycle Collet Head 1104 and is used to compress the collet in the downward movement as Treatment Valve 100 is opened. In one example, an Upper Collet Compression Face 1106 is used to compress the collet in the upward movement as Treatment Valve 1302 (shown in FIG. 13C ) is closed.
[0136] FIG. 12A shows a cross-sectional view of one example of the treatment valve assembly Housing for multi-cycle use. In one example, a Multi-Cycle Housing Collet Relief Groove 1202 is a groove placed into the Multi-Cycle Housing 1201 , which allows Multi-Cycle Collet Finger(s) 1102 (shown in FIG. 11A ) to be in a non-stressed state while Treatment Valve 100 , is in the closed position 200 . The placement of Multi-Cycle Collet Head 1104 in Housing Collet Relief Groove is shown in FIG. 13B . Also shown is Multi-Cycle Housing Collet Compression Face 1203 , which acts on Lower Multi-Cycle Collet Compression Face 1105 (shown in FIG. 11C ) to bend Multi-Cycle Collet Finger(s) 1102 (shown in FIG. 11A ) as Treatment Valve 100 is moved from the closed position 1301 .
[0137] FIG. 12B shows a cross-sectional detail-view of one example of multi-cycle Housing Open Retaining Face. In one example, a Multi-Cycle Housing Open Retaining Face 1204 is matched to Upper Multi-Cycle Collet Compression Face 1106 (one example shown in FIG. 11C ) to prevent Treatment Valve 100 from closing after actuation. The interaction of the two faces are further discussed using, and in the descriptions for, FIGS. 13C and 13D .
[0138] FIG. 13A shows a cross-sectional detail-view of one example of a multi-cycle treatment valve assembly with multi-cycle components in the shouldered position. In one example, a Treatment Valve 100 is shown in the shouldered position with Multi-Cycle components 1301 . In one example, this position is equivalent as that shown in FIG. 8A with Collet 202 replaced with Multi-Cycle Collet 1101 and Housing member 102 replaced with Multi-Cycle Housing 1201 .
[0139] FIG. 13B shows a cross-sectional detail-view of one example of the Multi-Cycle Collet Head positioned in the Multi-Cycle Housing Collet Relief Groove. In one example, Multi-Cycle Collet 1101 is shown in relation to Bottom Sub 103 and Multi-Cycle Housing 1201 with Treatment Valve 100 in position 1301 . In one example, a Multi-Cycle Collet Bottom Sub Gap 1303 is a standoff between the two components that prevent Multi-Cycle Collet Fingers 1102 from being loaded in compression, preventing, in one example, possible damage to Multi-Cycle Collet Fingers 1102 . Also shown are Upper Multi-Cycle Collet Compression Face 1106 and Multi-Cycle Housing Retaining Face 1204 . In one example, Multi-Cycle Housing Retaining Face 1204 and Multi-Cycle Collet Upper Compression Face 1106 are oriented at 60 degrees.
[0140] FIG. 13C shows a cross-sectional detail-view of one example of a multi-cycle treatment valve assembly with multi-cycle components in the open and locked position. In one example, Treatment Valve 100 is in the open position with Multi-Cycle components 1302 . This position is equivalent as that shown in FIG. 8C with Collet 202 replaced with Multi-Cycle Collet 1101 and Housing member 102 replaced with Multi-Cycle Housing 1201 .
[0141] FIG. 13D shows a cross-sectional detail-view of one example of the Multi-Cycle Collet Upper Compression Face engaged with the Multi-Cycle Housing Retaining Face. In one example, Multi-Cycle Collet 1101 is shown in relation to Multi-Cycle Housing 1201 , with the Treatment Valve 100 in position 1302 . Upper Multi-Cycle Collet Compression Face 1106 is shown in contact with Multi-Cycle Housing Retaining Face 1204 . In this position, any further upward movement of Inner Sleeve 201 requires force sufficient to compress Multi-Cycle Collet 1101 . In one example, the angle of Upper Multi-Cycle Collet Compression Face 1106 and Multi-Cycle Housing Retaining Face 1204 , along with the composition, thickness, width and length of Multi-Cycle Collet Finger(s) 1102 , determine the force required to compress Multi-Cycle Collet 1101 , allowing movement of Inner Sleeve 201 to close Treatment Valve 100 .
[0142] FIG. 14A shows a cross-sectional view of one example of the treatment valve assembly configured to use locking pins. In one example, a Locking Pin Treatment Valve in the closed position 1400 , is shown as is an alternate example of Treatment Valve 100 . In one example, one or more Locking Pins 1601 and one or more Locking Pin Spring Stacks 1603 are used to replace the function of Collet 202 . In one example, major components of Locking Pin Treatment Valve 1400 include: a Locking Pin Ported Top Sub 1401 , a Locking Pin Bottom Sub 1402 , and a Locking Pin Inner Sleeve 1403 . In this example, Locking Pin Ported Top Sub 1401 and Locking Pin Bottom Sub 1402 form the tool body. Locking Pin Top Sub 1401 and Locking Pin Bottom Sub 1402 are secured together with a threaded connection. In one example, Locking Pin Treatment Valve 1400 is deployed into a wellbore by placing it in-line with a production string. In one example, this is done by threading Locking Pin Bottom Sub 1402 of the assembled Locking Pin Treatment Valve 1400 into the production string as it is deployed into the wellbore, then threading the production string into Locking Pin Ported Top Sub 1401 , and continuing to deploy the production string into the wellbore.
[0143] In one example, a Locking Pin Inner Sleeve 1403 is radially disposed inside Treatment Valve 1400 and held in place by Shear Screw(s) 1404 which are inserted through Locking Pin Ported Top Sub 1401 . Shear Screw(s) 1404 are used to maintain the position of Locking Pin Inner Sleeve 1403 until Locking Pin Treatment Valve 1400 is opened. In one example, Lubrication Ports/Plugs (in one example, similar to those shown in FIG. 1 ) are used to provide lubrication to the actuating parts of Locking Pin Treatment Valve 1400 to increase the reliability of the assembly. In one example, the Lubrication Ports/Plugs are located and functionally equivalent to Lubrication Ports/Plugs 105 , as described in FIGS. 10A, 10D and 10E .
[0144] In one example, Locking Pin Inner Sleeve 1403 runs the length of Locking Pin Treatment Valve 1400 , from the Treatment Port Seal Assembly as shown in FIG. 14B , to the Lower Chamber Seal Assembly as shown in FIG. 14D . The Locking Pin Inner Sleeve 1403 serves two functions in this position. First, it isolates the inside of Treatment Valve 1400 from the outside of the Treatment Valve 1400 by isolating Treatment Port 1405 . Second, it is the inner member that forms the inner wall of Locking Chamber 1499 . In one example, Locking Chamber 1499 is equivalent in function and location as Locking Chamber 299 , which is described in detail in FIGS. 2A, 2B, 2C, 2D and 2E . In one example, another Oring Seal 1702 is used on Retaining Screw 1701 to seal Locking Chamber 1499 .
[0145] FIG. 14B shows a cross-sectional detail-view of one example of the Treatment Port Seal Assembly. FIG. 14B shows an example of the Treatment Port Seal Assembly, which is equivalent in function and location to the Treatment Port Seal Assembly shown and described in FIG. 2B .
[0146] FIG. 14C shows a cross-sectional detail-view of one example of the Upper Chamber Seal Assembly. FIG. 14C shows an example of the Upper Chamber Seal Assembly, which is equivalent in function and location to the Upper Chamber Seal Assembly shown and described in FIG. 2C .
[0147] FIG. 14D shows a cross-sectional detail-view of one example of the Lower Chamber Seal Assembly. FIG. 14D shows the Lower Chamber Seal Assembly, which is equivalent in function and location to the Lower Chamber Seal Assembly shown and described in FIG. 2D .
[0148] FIG. 14E shows a cross-sectional detail-view of one example of the Locking Pin Mechanism. FIG. 14E is a detailed view of the locking mechanism employed in Locking Pin Treatment Valve 1400 . The individual components and operation of the locking mechanism are described in detail in FIGS. 15, 16, 17 and 18 .
[0149] FIG. 15A shows a 3-D perspective external view of one example of the Locking Pin Inner Sleeve. FIG. 15A is an overall view of Locking Pin Inner Sleeve 1403 , which is used to isolate Locking Pin Treatment Ports 1404 , and embodies features to retain Locking Pin Inner Sleeve 1403 in various positions during operation.
[0150] FIG. 15B shows a cross-sectional view of one example of the Locking Pin Inner Sleeve. FIG. 15B is a cross-sectional view of Locking Pin Inner Sleeve 1403 and shows the details of features used to maintain the longitudinal position of Locking Pin Inner Sleeve 1403 in the various desired positions. A Locking Pin Shear Screw Groove 1501 is located near the top of Locking Pin Inner Sleeve 1403 and is located such that Shear Screw(s) 1404 , inserted through Locking Pin Ported Top Sub 1401 , can engage the groove. In one example, a Locking Groove 1502 is located longitudinally below Locking Pin Shear Screw Groove 1501 and is used to engage Locking Pin 1601 (as detailed in one example in FIGS. 17A and 17B ). In one example, a Locking Pin Running Surface 1503 is located longitudinally below Locking Pin Groove 1502 and is the surface that Locking Pin 1601 rides on while Locking Pin Treatment Valve is moved from the closed position 1400 to the open and locked position 1800 . In one example, a Locking Pin Inner Sleeve Landing Shoulder 1504 is equivalent in function and location to Inner Sleeve Landing Shoulder 604 .
[0151] FIG. 16A shows a 3-D perspective external view of one example of the Locking Pin. In one example, a Locking Pin 1601 is used to engage Locking Pin Groove 1502 . In one example, Locking Pin 1601 is a cylindrical member. The functionality of the Locking Pin in the overall locking mechanism are further discussed using, and in the descriptions for, FIGS. 17B and 18B .
[0152] FIG. 16B shows a 3-D perspective external view of one example of the Belleville Disc Spring. In one example, a Belleville Disc Spring is used for Locking Spring 1602 . A Belleville Disc Spring is a specially formed washer that deflects when loaded in compression, much like a typical compression spring. One of the advantages of the design is that Belleville Disc Springs typically provide spring constants larger than those attainable with wire wrapped springs of the same diameter. Another advantage of Belleville Disc
[0153] Springs is that they can be stacked in a variety of combinations to yield the desired deflection, or an increase in working load, or a combination of the two. One example of stacking is further discussed using, and in the description for, FIG. 16D .
[0154] FIG. 16C shows a cross-sectional view of one example of the Belleville Disc Spring. FIG. 16C shows one example of the formed shape of Locking Spring 1602 . In one example, Locking Spring 1602 is composed, shaped, positioned and arranged to deflect downward and have a subsequent reduction in height when subjected to a compressive force.
[0155] FIG. 16D shows a cross-sectional view of one example of the Locking Spring Stack. Locking Spring Stack 1603 is comprised of two or more Locking Springs 1602 , deployed as part of the locking mechanism for Locking Pin Treatment Valve 1400 . In one example, the stack arrangement is a series stack, meaning that each individual spring is stacked in an alternating orientation. A series stack is used to retain the working load of a single Belleville Disc Spring, or equivalent, while increasing the working deflection. In one example, a parallel stack is formed by arrangement where individual springs are stacked in the same orientation, retaining the working deflection of a single Belleville Disc Spring, or equivalent, while increasing the working load. In one example, a parallel-series combination stack is deployed, having a combination of individual springs, some stacked in parallel and some in stacked in series, resulting in both a working load and working deflection larger than a single Belleville Disc Spring, or equivalent.
[0156] FIG. 17A shows a cross-sectional view of one example of the treatment valve assembly configured to use locking pins, shown in the closed position. FIG. 17A is a cross-sectional view of the Locking Pin Treatment Valve in the closed position 1400 and is included to provide the location of the Locking Pin Mechanism, as shown in FIG. 17B , while the Locking Pin Treatment Valve is closed.
[0157] FIG. 17B shows a cross-sectional detail-view of one example of the Locking Mechanism in the closed position. FIG. 17B is a detail view of the Locking Pin Mechanism. The Locking Pin 1601 and Locking Spring Stack 1603 are radially disposed of in the Locking Pin Ported Top Sub 1401 and retained in place with a Retaining Screw 1701 . An Oring Seal 1702 is radially disposed on Retaining Screw 1701 to seal Locking Chamber 1499 . In the closed position 1400 , the Locking Pin 1601 is in contact with the Locking Pin
[0158] Running Surface 1503 of Locking Pin Inner Sleeve 1403 and Locking Spring Stack 1603 is compressed. When a downward force is applied to Locking Pin Inner Sleeve 1401 , sufficient to break Shear Screws 1404 , the Locking Pin Inner Sleeve 1403 will shift downward and Locking Pin(s) 1601 will ride on Locking Pin Running Surface 1503 .
[0159] FIG. 18A shows a cross-sectional view of one example of the treatment valve assembly configured to use locking pins, shown in the open and locked position. FIG. 18A is a cross-sectional view of the Locking Pin Treatment Valve in the open and locked position 1800 and is included to provide the location of the Locking Pin Mechanism, as shown in FIG. 18B , and the shouldering features in FIG. 18C , while the Locking Pin Treatment Valve is closed.
[0160] FIG. 18B shows a cross-sectional detail-view of one example of the Locking Mechanism in the open and locked position 1800 . Locking Pin 1601 is engaged in Locking Groove 1502 of Locking Pin Inner Sleeve 1403 . Locking Spring Stack 1603 is shown in an extended state, which forces Locking Pin 1601 into Locking Groove 1503 . In this state Locking Pin 1601 is engaged in both Locking Pin Ported Top Sub 1401 and Locking Groove 1503 , which prevents further movement of Locking Pin Inner Sleeve 1403 , thus retaining the Locking Pin Treatment Valve in the open and locked position 1800 .
[0161] FIG. 18C is a detailed view that shows the shouldering of the Locking Pin Inner Sleeve, 1403 , in the Locking Pin Bottom Sub, 1402 . The engagement occurs at the Locking Pin Inner Sleeve Shouldering Face 1504 and the Locking Pin Bottom Sub Shouldering Face 1801 . The interaction of these two faces achieve the open and locked position 1800 of the Locking Pin Treatment Valve 1400 .
[0162] FIG. 18C shows a cross-sectional detail-view of one example of a shoulder stop surface, shouldering Locking Pin Inner Sleeve 1403 in Locking Pin Bottom Sub 1402 . The contact engagement occurs at Locking Pin Inner Sleeve Shouldering Face 1504 and Locking Pin Bottom Sub Shouldering 1801 . In one example, the interaction of the two faces control the longitudinal positioning of Locking Pin Inner Sleeve 1403 , preventing any downward loading of Locking Pin(s) 1601 . In one example, the shouldered faces are placed at 60 degree angles.
[0163] FIG. 19 shows a flowchart describing examples of the method of operation of the Treatment Valve. In one example, the treatment valve assembly is assembled, in one example, in a shop (step 1901 ), and then deployed it in a wellbore, in one example, using a production string (step 1902 ). In one example, the treatment valve assembly is run in the wellbore with an activation tool (step 1903 ). In one example, the activation tool is a service packer. In one example, a service packer is deployed and set in the Treatment Valve 100 . In one example, the service packer is deployed with Coiled Tubing. In one example, the service packer is deployed with jointed pipe. In one example, Treatment Valve 100 is first located by using Locator Groove 211 or equivalent marker (step 1904 ). After locating Treatment Valve 100 , and setting the service packer, Treatment Valve 100 is shifted open (step 1905 ) and the treatment placed (steps 1906 , 1907 ). In one example, if the treatment cannot be initiated, a dissolving fluid is placed across Treatment Valve 100 and forced through Treatment Port Cover 402 (steps 1908 , 1909 ), and then the treatment is placed (step 1907 ). After the treatment has been placed the service packer is unset (step 1910 ). If there are more Treatment Valves 100 to be utilized, the process is started again at locating the Treatment Valve 100 (step 1904 ). If there are no more Treatment Valves 100 to be utilized, the service packer is pulled out of hole (step 1911 ).
[0164] While this invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention disclose.
[0165] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive and it is not intended to limit the invention to the disclosed embodiments. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used advantageously. Any reference signs in the claims should not be construed as limiting the scope of the invention. | A cover configured to dispose over a treatment port of a downhole treatment tool, the cover comprising a dissolvable material. A system for protecting treatment ports in a downhole treatment tool, the treatment tool having an outer surface and an inner bore, the inner bore in fluid communication with the outer surface through one or more treatment port orifices disposed on the outer surface of the treatment tool, and a dissolvable treatment port cover disposed in the fluid communication path of the treatment port. A method for treatment of a well including the steps of locating a treatment tool in a well, the treatment tool having a treatment port and a cover over the treatment port; setting an activation tool in the well; placing a treatment, applying pressure to rupture the cover; and unsetting the activation tool. | 4 |
[0001] This Application is a division of and claims priority of copending U.S. patent application Ser. No. 11/427,486 filed on Jun. 29, 2006.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of semiconductor devices; more specifically, it relates to FinFET device structures and methods of fabricating FinFET structures.
BACKGROUND OF THE INVENTION
[0003] FinFET (Fin field-effect-transistor) is an emerging technology, which allows smaller and higher performance devices. FinFET structures comprise narrow isolated bars of silicon (fins) with a gate(s) on the sides of the fin. Prior art FinFET structures are formed on silicon-on-insulator (SOI) substrates. However, FinFETs fabricated on SOI substrates suffer from floating body effects. The floating body of a FinFET on an SOI substrate stores charge, which is a function of the history of the device. As such, floating body FinFETs experience threshold voltages which are difficult to anticipate and control, and which vary in time. The body charge storage effects result in dynamic sub-Vt leakage and Vt mismatch among geometrically identical adjacent devices. FinFETs fabricated on bulk silicon substrates do not experience floating body effects, but they do experience greatly increased source/drain to substrate capacitance. Increased source-drain to substrate capacitance is a parasitic effect, which degrades performance (speed).
[0004] Therefore, there is a need for FinFET devices and methods of fabricating FinFET devices without floating body effects and with reduced parasitic capacitance.
SUMMARY OF THE INVENTION
[0005] A first aspect of the present invention is a structure comprising: a finFET having a silicon body formed on a bulk silicon substrate; a body contact between the silicon body and the substrate; and first and second source/drains formed in the silicon body and insulated from the substrate by a dielectric layer under the fins.
[0006] A second aspect of the present invention is a structure, comprising: a single crystal silicon fin extending in a first direction parallel to a top surface of a bulk silicon substrate, the fin having a channel region between first and a second source/drains; an electrically conductive gate electrode extending in a second direction parallel to the top surface of the substrate and crossing over the channel region, the second direction different from the first direction; a gate dielectric between the gate electrode and the fin; at least a portion of the channel region of the fin in direct physical and electrical contact with the substrate; and a dielectric layer between at least a portion of the first source/drain and the substrate and between at least a portion of the second source/drain and the substrate.
[0007] A third aspect of the present invention is a method, comprising: forming a silicon fin on a top surface of a silicon substrate; forming a gate dielectric on opposite sidewalls of the fin; forming a gate electrode over a channel region of the fin, the gate electrode in direct physical contact with the gate dielectric layer on the opposite sidewalls of the fin; forming a first source/drain in the fin on a first side of the channel region and forming a second source/drain in the fin on a second side of the channel region; removing a portion of the substrate from under at least a portion of the first and second source/drains to create a void; and filling the void with a dielectric material.
BRIEF DESCRIPTION OF DRAWINGS
[0008] The features of the invention are set forth in the appended claims. The invention itself, however, will be best understood by reference to the following DETAILED DESCRIPTION of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
[0009] FIGS. 1A through 1F are cross-sectional views illustrating initial steps in the fabrication of FinFETs according to embodiments of the present invention;
[0010] FIG. 2 is a three dimensional isometric view of the structure illustrated in FIG. 1F ;
[0011] FIG. 3 is a three dimensional isometric view of the structure illustrated in FIG. 2 after additional fabrication steps;
[0012] FIG. 4 is a top view and FIGS. 5A , 5 B, 5 C and 5 D are cross-sectional views through respective lines 5 A- 5 A, 5 B- 5 B, 5 C- 5 C and 5 D- 5 D of the structure illustrated in FIG. 3 ;
[0013] FIG. 6 is a top view and FIGS. 7A , 7 B, 7 C and 7 D are cross-sectional views through respective lines 7 A- 7 A, 7 B- 7 B, 7 C- 7 C and 7 D- 7 D of the structure illustrated in respective FIGS. 4 , 5 A, 5 B, 5 C and 5 D after additional processing;
[0014] FIG. 8 is a top view and FIGS. 9A , 9 B, 9 C and 9 D are cross-sectional views through respective lines 9 A- 9 A, 9 B- 9 B, 9 C- 9 C and 9 D- 9 D of the structure illustrated in respective FIGS. 6 , 7 A, 7 B, 7 C and 7 D after additional processing; and
[0015] FIG. 10 is a top view and FIGS. 11A , 11 B, 11 C and 11 D are cross-sectional views through respective lines 11 A- 11 A, 11 B- 11 B, 11 C- 11 C and 111 D- 11 D of the structure illustrated in respective FIGS. 8 , 9 A, 9 B, 9 C and 9 D after additional processing.
DETAILED DESCRIPTION OF THE INVENTION
[0016] FIGS. 1A through 1F are cross-sectional views illustrating initial steps in the fabrication of FinFETs according to embodiments of the present invention. In FIG. 1A , formed on a bulk silicon substrate 100 is a pad silicon oxide layer 105 and formed on the pad oxide layer is a pad silicon nitride layer 110 . A bulk silicon substrate is defined as a monolithic block of single-crystal-silicon. Formed through pad silicon oxide layer 105 and pad silicon nitride layer 110 is a dielectric shallow trench isolation (STI) 115 . An optional dielectric liner 120 around the sides and bottom surfaces, but not the top surface, of STI 115 is shown. STI 115 may be formed, by photolithographically defining openings in the pad silicon oxide 105 and silicon nitride 110 layers, etching (for example, by reactive ion etch (RIE)) a trench into substrate 100 where the substrate is not protected by the pad layers, backfilling the trenches with dielectric and performing a chemical-mechanical-polish (CMP) so a top surface of the STI is co-planar with a top surface of the pad silicon nitride layer.
[0017] In one example, pad oxide layer 105 is formed by thermal oxidation of substrate 100 and between about 5 nm and about 20 nm thick. In one example, pad silicon nitride layer 110 is formed by chemical-vapor-deposition (CVD) and is between about 50 nm and about 500 nm thick. In one example, STI 115 comprises a CVD oxide such as tetraethoxysilane (TEOS) or high-density-plasma (HDP) oxide. In one example, liner 120 comprises less than 50 nm of silicon oxide, silicon nitride or a dual layer of silicon oxide under silicon nitride. In one example, STI 115 is between about 50 nm and about 500 nm thick. Pad silicon nitride layer 110 is then stripped selective to oxide and STI 115 is planarized to be approximately flush with the top surface of pad oxide layer 105 .
[0018] In FIG. 1B , an etch stop layer 125 is deposited over pad silicon oxide 110 , STI 115 and exposed edges of liner 120 if present, and a mandrel layer 130 is deposited over the etch stop layer. In one example, etch stop layer comprises CVD silicon nitride and is between about 2 nm and about 10 nm thick. In one example, mandrel layer 130 is CVD oxide described supra, and is between about 100 nm and about 500 nm thick. The thickness of mandrel layer determines the height of the silicon fin (above the current bulk silicon 100/pad silicon oxide layer 125 interface) that will be formed subsequently.
[0019] In FIG. 1C , a trench 135 is etched through mandrel layer 130 and etch stop layer 125 to expose substrate 100 in the bottom of the trench. In one example, trench 135 has a width “W” of between about 20 and about 100 nm wide. The width “W” defines the width of the silicon fin (less any subsequent sidewall oxidations, if any) to be subsequently formed.
[0020] In FIG. 1D , a single-crystal silicon fin 140 covered by a cap 145 is formed in trench 135 . Fin 140 may be formed by selective epitaxial growth to above the top surface of mandrel layer 130 followed by planarization and a recess RIE. In one example, the top of fin 140 is recessed between about 20 nm and about 100 nm below the top surface of mandrel layer 130 . In one example, cap 145 may be formed by CVD deposition of silicon nitride of sufficient thickness top overfill the recess followed by a CMP so a top surface of cap 145 is coplanar with a top surface of mandrel 130 . Alternatively, a polysilicon fin may be formed instead of a single-crystal silicon fin.
[0021] In FIG. 1E , mandrel 130 (see FIG. 1D ) is removed. In one example, when mandrel layer 130 is oxide and cap 145 and etch stop layer 125 are silicon nitride, the mandrel is removed with an RIE selective to etch oxide faster than silicon nitride. Alternatively, mandrel layer 130 may be removed by a wet etching process (i.e. aqueous hydrofluoric acid when mandrel 130 is a silicon oxide). Then etch stop layer 125 is removed with a RIE selective to etch silicon nitride faster than silicon oxide, in which case cap 145 (see FIG. 1D ) is thinned to form cap 145 A.
[0022] In FIG. 1F , a gate dielectric layer 150 is formed on the sidewalls of fin 140 . In the present example, gate dielectric 150 is a thermally grown silicon oxide, so a thin region of exposed substrate 100 is also oxidized. Alternatively, gate dielectric 150 may be deposited. In the example of a deposited gate dielectric, gate dielectric 150 may be a high K (dielectric constant) material, examples of which include but are not limited metal oxides such as Ta 2 O 5 , BaTiO 3 , HfO 2 , ZrO 2 , Al 2 0 3 , or metal silicates such as HfSi x O y or HfSi x O y N z or combinations of layers thereof. A high K dielectric material has a relative permittivity above about 10. In one example, gate dielectric 150 is between about 0.5 nm and about 20 nm thick.
[0023] Next a gate 155 is formed crossing over fin 140 and a capping layer 160 formed on the top (but not the sidewalls of the gate (see FIG. 2 ). In one example, gate 155 comprises doped or undoped polysilicon or a highly silicided metal layer and is at least thick enough to cover the sidewalls of fin 140 . In one example, capping layer 160 is silicon nitride and is between about 100 nm and about 500 nm thick.
[0024] FIG. 2 is a three dimensional isometric view of the structure illustrated in FIG. 1F . In FIG. 2 , gate 155 and capping layer cross fin 140 . In one example, fin 140 and gate 155 are orthogonal to each other. In one example, fin 140 and gate 155 may cross at an angle defined by a crystal plane of the fin. In one example, gate 155 and capping layer 160 are formed by blanket CVD deposition of the gate, followed by a CMP, followed by blanket CVD deposition of the capping layer followed by a photolithographic and etch process to define the gate and capping layer.
[0025] FIG. 3 is a three dimensional isometric view of the structure illustrated in FIG. 2 after additional fabrication steps. In FIG. 3 , source/drains 180 are formed by ion implantation and then a first protective layer 165 is formed on the exposed sidewalls of fin 140 and gate 155 , a second protective layer 170 formed over first protective layer 165 on the sidewalls of gate 155 and a spacer 175 formed on top edges of first and second protective layers 165 and 170 adjacent to capping layer 160 . Formation of first and second protective layers 165 and 170 and spacer 175 may be accomplished, in one example by:
[0026] (1) performing a blanket CVD deposition of silicon nitride to form a blanket of layer first protective layer 165 ;
[0027] (2) performing a blanket deposition of a CVD oxide (as described supra) to form a blanket layer of second protective layer 170 over the blanket of layer first protective layer 165 ;
[0028] (3) performing a CMP of the CVD oxide to expose capping layer 160 ;
[0029] (4) performing a RIE recess etch to recess the CVD oxide below the top surface of capping layer 160 ;
[0030] (5) performing a blanket CVD silicon nitride deposition followed by a spacer RIE to form spacers 175 ; and
[0031] (6) performing a RIE to remove all CVD oxide not protected by spacers 175 .
[0032] FIG. 4 is a top view and FIGS. 5A , 5 B, 5 C and 5 D are cross-sectional views through respective lines 5 A- 5 A, 5 B- 5 B, 5 C- 5 C and 5 D- 5 D of the structure illustrated in FIG. 3 . It should be noted in FIGS. 5B , 5 C and 5 D that the boundaries of source/drains 180 are indicated by the small-dash dashed lines. In FIGS. 5A and 5D , the interface between substrate 100 and fin 140 is indicated by the large-dash dashed line even though this interface is not detectable since the fin was grown epitaxially. It is shown for reference purposes. Also in FIGS. 5A and 5D , a channel region 185 exists under gate 155 in fin 140 .
[0033] FIG. 6 is a top view and FIGS. 7A , 7 B, 7 C and 7 D are cross-sectional views through respective lines 7 A- 7 A, 7 B- 7 B, 7 C- 7 C and 7 D- 7 D of the structure illustrated in respective FIGS. 4 , 5 A, 5 B, 5 C and 5 D after additional processing. FIGS. 7A and 7D are identical to respective FIGS. 5A and 5D . In FIGS. 6 , 7 B and 7 C a trench 7 C has been etched into substrate 100 a depth “D” using, for example, an RIE selective to etch silicon faster than silicon dioxide and silicon nitride wherever the substrate is exposed (see FIGS. 4 , 5 B and 5 C). In one example “D:” is between about 50 nm and about 250 nm. In one example, “D” is about one half the thickness of STI 115 (or the thickness of STI 115 and liner 120 , if liner 1120 is present). Fin 140 is protected from etching by cap 145 A, gate dielectric 150 and protective layer 165 while gate 155 is protected from etching by first and second protective layers 165 and 170 as well as cap 160 and spacers 175 .
[0034] FIG. 8 is a top view and FIGS. 9A , 9 B, 9 C and 9 D are cross-sectional views through respective lines 9 A- 9 A, 9 B- 9 B, 9 C- 9 C and 9 D- 9 D of the structure illustrated in respective FIGS. 6 , 7 A, 7 B, 7 C and 7 D after additional processing. FIG. 9A is identical with FIG. 7A . In FIGS. 8 , 9 B, 9 C and 9 D a wet etch of silicon has been performed to enlarge trench 190 (see, FIGS. 7B and 7C ) to form trench 190 A and undercut fin 140 in source/drains 180 leaving a pedestal 195 of silicon connecting fin 140 to substrate 100 in channel region 185 . Pedestal 195 has an edge 200 indicated by the dashed line in FIG. 8 . Depending upon the amount of undercutting, source/drain regions 180 may be completely or partially undercut and the cross-sectional area of pedestal 195 may vary. There may or may not be undercutting of channel region 185 . As an example, channel region 185 is partially undercut and the source/drains (not shown in FIG. 9D ) are completely undercut and not present in FIG. 9D . A portion of substrate 100 and fin 140 is removed in the undercutting process. The undercutting may be performed isotropically, for example, by wet etching in a mixture of nitric and hydrofluoric acids or by RIE using CF 4 or SF 4 . Alternatively, the undercutting may be performed an-isotropically by wet etching in an aqueous or alcoholic solution of a strong base such as potassium hydroxide or tetrametylammonium hydroxide which etches the [001] crystal plane of silicon faster than the [001] crystal plane. Pedestal 195 provides an electrically conductive body contact between channel region 185 and substrate 100 , effectively eliminating floating body effects.
[0035] FIG. 10 is a top view and FIGS. 11A , 11 B, 11 C and 11 D are cross-sectional views through respective lines 11 A- 11 A, 11 B- 11 B, 11 C- 11 C and 11 D- 11 D of the structure illustrated in respective FIGS. 8 , 9 A, 9 B, 9 C and 9 D after additional processing. In FIGS. 10 , 11 A, 11 B, 11 C and 11 D a dielectric layer 205 is deposited, filling (shown) or partially filling (not shown) the undercut regions of trench 190 A. A top surface of dielectric layer 205 is coplanar with a top surface of capping layer 160 . In one example, dielectric layer 205 is formed by conformal CVD oxide deposition (such as TEOS or HDP) followed by a CMP. It is permissible not to completely fill undercut regions 190 A and leave voids because the remainder of dielectric layer 205 will seal any voids. The distance “T” between fin 140 and substrate 100 under source/drains 180 (see FIG. 11D ) whether completely filled or containing voids, greatly reduces parasitic capacitance between the fin and the substrate. In one example, “T” is between about 50 nm and about 250 nm.
[0036] Contacts (not shown, but well known in the art) may be formed to the finFET by forming contact via holes through dielectric 205 and capping layers 145 A and 160 to source-drains 180 and gate 155 , filling the via holes with metal (e.g. barrier liner and tungsten) and performing a CMP. Next, standard processing including formation of levels of wiring and intervening dielectric layers are formed through completion of an integrated circuit chip containing finFET devices according to embodiments of the present invention.
[0037] Thus, the embodiments of the present invention provide FinFET devices and a method of fabricating FinFET devices without floating body effects and with reduced parasitic capacitance.
[0038] The description of the embodiments of the present invention is given above for the understanding of the present invention. It will be understood that the invention is not limited to the particular embodiments described herein, but is capable of various modifications, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore it is intended that the following claims cover all such modifications and changes as fall within the true spirit and scope of the invention. | A finFET structure and a method of fabricating the finFET structure. The method includes: forming a silicon fin on a top surface of a silicon substrate; forming a gate dielectric on opposite sidewalls of the fin; forming a gate electrode over a channel region of the fin, the gate electrode in direct physical contact with the gate dielectric layer on the opposite sidewalls of the fin; forming a first source/drain in the fin on a first side of the channel region and forming a second source/drain in the fin on a second side of the channel region; removing a portion of the substrate from under at least a portion of the first and second source/drains to create a void; and filling the void with a dielectric material. The structure includes a body contact between the silicon body of the finFET and the substrate. | 7 |
FIELD OF THE INVENTION
The present invention relates to memory devices and, in particular, those memory devices which have a power-down mode, and relates to methods and apparatus for inhibiting and/or preventing address transition detection signals from causing potential access time push-outs within such devices at a power-up transition from such a mode.
BACKGROUND
Memory devices that include so-called power-down modes have been developed in an attempt to reduce the amount of current drawn by the device when not actively being used. An example of such a memory device 10 is shown is FIG. 1. Memory device 10 includes a data input path in which data signals 12 received at input pins of the device are conditioned (e.g., converted to appropriate internal levels, usually CMOS) in data buffers 14. In response to internal write signals 16 (which may be generated in response to appropriate external control signals), the data signals arc driven, using bus drivers 18, onto selected bit lines 20a and 20b. The bits lines 20a and 20b are associated with a particular column of memory cells 22, the column corresponding to the particular bit line pair being driven. When memory device 10 is not being actively written to or read from, the bit lines are equalized through the use of static and/or dynamic bit line pull up circuits 24, as is well known in the art. The read path circuitry of memory device 10 is not shown in detail, however, it may include conventional elements such as sense amplifiers and appropriate interface circuitry to provide signals from the memory cells to the output pins of the device.
Also shown in FIG. 1 is a portion of the address path circuitry for memory device 10. Address signals 26 are conditioned in associated address input buffers 28. The address signals may be provided to appropriate decoding circuitry, such as the row predecoders 30, in order to access selected rows (wordlines) of memory device 10. Further details regarding the row decoding circuitry is not shown in order not to obscure the diagram.
In addition to driving the word-line decoding circuitry, signals from the address input buffers 28 are provided to individual address transition detection (ATD) signal generators 32 to produce individual ATD signals 34. The individual ATD signals 34 provide an indication that an address switching event has occurred at the input of the memory device. Such address switching events are generally associated with read and write operations, and the associated ATD pulses are often used in memory devices to perform functions such as bit line equalization. For example, prior to any read, bit lines of the memory device must be properly equalized so as not to provide initial false readings to the associated sense amplifiers. The individual ATD signals 34 may be combined at an ATD combination stage 36 to produce a global ATD signal 38 which may be used for such functions. The ATD signal 38, together with appropriate block decoding and write detect signals 40 and 42, respectively, may be provided to the control circuitry 44 to control the dynamic bitline pullups, to enable/disable the sense amplifiers, as appropriate, and/or to allow write access to the bit lines from the data write bus drivers 18. Further details regarding such circuitry may be found in U.S. Pat. No. 5,825,715, incorporated herein by reference.
In addition to using the individual ATD signals 34, the ATD combination block 36 relies on a signal provided by a chip enable input buffer 46 of memory device 10. Chip enable input buffer 46 receives a chip enable (e.g., CE, active low) signal 48, which is typically provided to an input pin of the memory device 10. In response, input buffer 46 provides an output signal 50, which may be delayed by an appropriate period (τ 2 ) through a delay block 52 before being passed to the ATD combination block 36. In this way appropriate timing for the global ATD signal 38 may be provided, simultaneously with its activation during standby, usually for bitline equalization purposes.
Chip enable input buffer 46 also provides a fast power-up signal 54 to thc address input buffers 28. This fast power-up signal 54 is used to indicate that the memory device 10 is about to enter a power-down mode, in which the outputs of the address input buffers 28 are brought to a predetermined logic state, or is powering-up from such a power-down mode. In some cases, the fast power-up signal 54 may also be provided to the row predecoders 30, for example through an appropriate delay (τ 1 ) 56.
In operation, when memory device 10 is placed in a power-down mode, indicated by the memory device being deselected (i.e., CE at a high logic level), the address input buffers 28 are forced to a predetermined state so that in case the address is changed externally (e.g., as may be the case where a different memory device is selected). the input buffers do not toggle, and thus the power consumption is kept lower. When the address buffers are placed in such a state, a corresponding address (e.g., address 00 . . . 00) might be active within memory device 10. As a result, when the memory device is powered-up and a new address is selected, an ATD pulse will be generated.
The generation of such an ATD pulse presents a problem in that the normal device access time will be pushed out. For example, consider that a normal access time (Taa) is a function of the normal ATD pulse width. However, at power-up the ATD signal itself is not produced until the fast power-up signal 54 is received from the chip enable input buffer 46. In other words, the access time due to the chip enable function (Tace) is a function of the delay within the chip enable input buffer 46 plus the regular access time Taa. Thus, Tace becomes a limiting factor for the speed of memory device 10 and, generally, this not an acceptable condition.
Although others have recognized this access timing problem associated with memory devices that allow for power-down modes, the solutions that have been proposed to date are generally unacceptable. For example, Shinohara et al., proposed a chip select speed-up circuit that accelerated the trailing edge of an ATD signal within a memory device. See, Shinohara et al., A 45-ns 256 k CMOS Static RAM with a Tri-Level Wordline, IEEE Journal of Solid-State Circuits, vol. SC-20, No. 5, pp. 929-34, at 931 (October 1985). Although the acceleration of the trailing edge of the ATD signal may improve access time somewhat, it does not eliminate the problem posed by the Tace push-out. Indeed, because the solution proposed by Shinohara et al., does not eliminate the ATD signal generated at power-up, one can expect the Tace condition to always remain a limiting factor for memory devices incorporating such a solution.
A second solution that has been proposed by Flannagan et al., uses what appears to be rather complex circuitry in an effort to correlate various internal signals within the memory device. See Flannagan et al., IEEE Journal of Solid State Circuits Vol. SC-21, No. 5, pp. 692-703, at 697-98 (October 1986). In their design, Flannagan et al. proposed inhibiting the ATD signal which would be otherwise generated at power-up but failed to discuss any details regarding how this inhibiting function is performed. In addition, it appears that the solution proposed by Flannagan et al. may suffer from push-out penalties of its own if the first access after the stand-by mode is made to the same column of memory cells as was addressed by the predetermined power-down address, especially where data of the opposite logic state is to be read.
Moreover, given the logic circuitry shown by Flannagan et al. (see FIG. 10 at p. 697), it does not appear that an ATD signal will be inhibited only if a proper bit line equalization has been assured during the power-down state. To elaborate, consider that the Flannagan design uses separate ATD and chip enable signal paths that are ultimately combined in a summation OR-type gate. This design dictates that the block (no label is provided for this block) in the ATD signal path determines the duration of the ATD pulse. Also, the minimum duration of the stand-by equalization pulse cannot help but be determined by the block (again unlabeled) in the chip enable signal path. At the very least, such a design would make it difficult to assure proper bit line equalization during stand-by.
Accordingly, what is needed is a solution for the Tace condition described above that overcomes the failings of previously posed solutions therefor.
SUMMARY OF THE INVENTION
In one embodiment, a method that includes detecting a power-up transition at a memory device having a power-down mode and inhibiting, in response to the power-up transition, an address transition detection (ATD) signal within the memory device is provided. Importantly, in this embodiment the ATD signal is inhibited at power-up, but making sure a perfect bit line equalization took place during power-down within the memory device. In addition, the wordlines of the memory device may be disabled during the power-down mode and subsequently enabled (e.g., after a delay synchronized with the valid address delay) in response to the power-up transition. The ATD signal itself may be inhibited by generating a pulse of sufficient time duration to decouple one or more individual ATD pulse generators. As a result, the ATD combined pulse is prevented from activating the dynamic bit line equalization control circuitry within the memory device. Such a pulse may be generated by combining a pair of signals produced in response to the power-up transition, at least one of the signals being delayed in time with respect to the other. This combination may be accomplished by circuitry which provides a logical NOR operation.
In a further embodiment, a method that includes disabling, during a power-down mode, one or more wordlines of a memory device and, in response to a power-up transition, enabling the wordlines and inhibiting an ATD signal within the memory device is provided. As above, the wordlines may be enabled following a delay tracking the address path delay, in order to ensure that a valid address is available. Also, the ATD signal may be inhibited by decoupling one or more ATD signal generators from the dynamic bit line equalization control circuitry within the memory device. Such decoupling may include removing power from a logic gate within the ATD signal generator for a time sufficient to mask the ATD signal that would otherwise be generated. This may be accomplished, for example, by gating a transistor coupled between a power source and the logic gate.
In yet another embodiment, a method that includes preventing an ATD signal from being produced within a memory device at a power-up transition from a power-down mode by latching the addresses at the memory device following an indication that the memory device is about to enter the power-down mode is provided. Such latching may be performed in response to a power-down signal provided within the memory device; the power-down signal being provided after a delay sufficient to ensure a stable valid address will be available.
In still another embodiment, a memory device is provided and includes a first circuit configured to inhibit an ATD signal at a power-up transition from a power-down mode. The memory device may also include a second circuit configured to enable one or more wordlines of the memory device in response to the power-up transition. In some cases, the first circuit may be a pulse generator that is configured to combine a pair of signals produced in response to the power-up transition, one of the pair of signals being time delayed with respect to the other. Such a combination may be provided using a logical NOR gate within the pulse generator. The output of the NOR gate may be provided to a third circuit which is configured to decouple the ATD signal from bit line equalization circuitry within the memory device. Such a third circuit may include a logic gate coupled to receive an address signal and to produce an ATD signal in response thereto, the logic gate being decoupled from an associated power source by the output signal of the NOR gate. Such decoupling may be accomplished by gating a transistor coupled between the power source and the logic gate.
In other cases, the first circuit of the memory device may be an address buffer configured to store an address input thereto in response to an indication that the memory device is about to enter a power-down mode. Such an address buffer may include a level-triggered storage device coupled to receive a delayed version of the power-down signal. or an edge-triggered flip-flop coupled to receive such a signal.
Other features and advantages provided by the present invention will be described with reference to the accompanying drawings in the discussion below.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example, and not limitation, in the figures of the accompanying drawings in which:
FIG. 1 illustrates a conventional memory device which may have an associated power-down mode when not actively selected;
FIG. 2 illustrates a portion of the address input path for the memory device of FIG. 1;
FIG. 3 illustrates an individual ATD signal generator within the address path of the memory device shown in FIG. 1;
FIG. 4 illustrates a transition detection pulse generator for the individual ATD signal generator shown in FIG. 3;
FIG. 5 is a timing diagram for the transition detection pulse generator shown in FIG. 4;
FIG. 6 illustrates a portion of the address input circuitry of a memory device configured in accordance with one embodiment of the present invention;
FIG. 7 illustrates a pulse generator for use in the address path circuitry of FIG. 6 in accordance with one embodiment of the present invention;
FIG. 8 is a timing diagram for the pulse generator shown in FIG. 7;
FIG. 9 illustrates an individual ATD signal generator with disable capability for use in the address path circuitry shown in FIG. 6, in accordance with an embodiment of the present invention;
FIG. 10 illustrates a transition detection pulse generator with disable capability for use in the individual ATD signal generator shown in FIG. 9, in accordance with an embodiment of the present invention;
FIG. 11 is a timing diagram for the individual ATD signal generator shown in FIG. 9;
FIG. 12 illustrates an embodiment of an address input buffer for use in a memory device in accordance with yet another embodiment of the present invention;
FIG. 13 is a timing diagram for the address input buffer shown in FIG. 12;
FIG. 14 illustrates an alternative embodiment for an address input buffer for use in a memory device in accordance with still a further embodiment of the present invention;
FIG. 15 is a timing diagram for the address input buffer shown in FIG. 14; and
FIG. 16 illustrates the improvement in Tsce that may be experienced as a result of inhibiting an ATD pulse at power-up in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
In a following discussion, an example of the present invention which utilizes an input-buffer-driven ATD-inhibit structure to prevent an extended access time at power-up is presented. Within the scheme, a wordline disable function may be incorporated so as to prevent an access to a predetermined power-down address. This avoids wordline glitches (e.g., through an address corresponding to a predetermined state stored during a power-down mode), which may otherwise be experienced at power-up. Additionally. alternative embodiments in which an address input buffer is used to store a true logic value of its input shortly after a memory device is switched into a power-down mode arc discussed. Although such schemes represent examples of the present invention, they should not be viewed as limiting the broader spirit and scope thereof. For example, after reviewing the various schemes presented below, those of ordinary skill in the art will recognize that various modifications may be made thereto, without altering the fundamental ideas behind the present invention. Accordingly, the claims which follow this discussion should not be deemed as limited by the examples presented below.
As described above with reference to FIG. 1, in those memory devices which are capable of being placed in a stand-by or powered-down mode, the chip enable access time (Tace) may be extended beyond a normal access time (Taa) as a result of the combined effects of a delayed power-up (chip enable activated) signal provided to the address buffers, and a correspondingly delayed ATD pulse. In order to more fully appreciate the advantages offered by the present invention, some further details regarding the circuitry shown in FIG. 1 is appropriate. For example, FIG. 2 shows a portion of the address input path illustrated in FIG. 1. Address input path 60 includes a number of address input buffers 28. The number, n, of address input buffers 28 is determined by the number address lines 26 provided to the memory device 10. Address input buffer 28 also receives the fast power-up signal 54 from the chip enable input buffer 46. In response, address input buffer 28 provides address signals An and An, 62a and 62b, respectively, which usually are delayed and level-conditioned, true and complement counterparts of the address input signal 26. These signals are provided to predecoding circuitry, including the wordline (row) pre-decoders 30 as described above, and to the input of an individual ATD signal generator 32. The individual ATD signal generator provides an ATD signal 34 to the ATD combined block 36, where n such signals are combined to produce the global ATD signal, as discussed above with reference to FIG. 1.
FIG. 3 illustrates various details of the individual ATD signal generator 32 in greater detail. As shown, each individual ATD signal generator 32 is made up of a transition detection pulse (TDP) generator 66 and an associated pull-down transistor (e.g., an n-channel transistor) 68. For the complete memory device 10, n such individual ATD signal generators 32 will be present. In operation, TDP generator 66 uses the true and complement address signals 62a and 62b to produce output signal TDP, which gates pull-down transistor 68. Thus, when signal TDP is active (logic high) pull-down transistor 68 pulls the logic level of the individual ATD signal 34 low. Such a signal indicates an address transition on the address line 26 input to the corresponding address input buffer 28.
As shown in FIG. 4, signal TDP is produced using a logic gate 70, which receives as inputs true and complement signals TDn and TDn, 72a and 72b respectively. Signals TDn and TDn are the same signals as the address signals An and An, 62a and 62b, respectively, with one of those signals having passed though a delay block τ so that it is delayed in time with respect to the other. Either of these address signals may be delayed with respect to the other according to whether the address input signal 26 is transitioning from logic high to logic low or logic low to logic high. Thus, the presence or absence of a particular delay block X in the signal path of either of these address signals 62a or 62b is shown though the use of dotted outlines. In one example, shown in FIG. 5, the signal TDn is delayed with respect to its logic complement TDn. Thus, signal
TDn has the same profile as the address input signal An, and signal TDn has the same profile as address input signal An, but is delayed in time with respect to An by a time τ.
For the case where logic gate 70 is a NOR gate, signal TDP will be produced when both signals TDn and TDn are logic low, as shown in FIG. 5.
Notice also that logic gate 70 is powered from a power source, Vcc. Thus, when signal TDP is active, pull-down transistor 68 is turned on and the associated individual ATD 34 is produced. This individual ATD signal is provided to the ATD combined block 36 as shown in FIG. 1, thus contributing to the global ATD signal 38. As indicated above, global ATD signal 38 is provided to the dynamic bit line equalization control circuitry 44, which may act to equalize bit lines such as 20a and 20b prior to a read operation in memory device 10. During the bit line equalization, the bit lines might be made inaccessible to a write operation, cutting off the two n-channel pass gates shown in FIG. 1 between DW and DW and the bitlines. See, e.g., U.S. Pat. No. 5,825,715.
Now, to prevent an ATD signal which would otherwise be generated by the above described circuitry at a power-up transition (i.e., in response to switching from the standby predetermined state to the true value of the corresponding address input of the memory device 10), the circuitry shown in FIG. 6 is introduced in the address input path of memory device 10. This address input path with ATD disable capability 80 includes the familiar address input buffer 28, which receives address input signals 26 and the power-up signal 54 from chip enable input buffer 46. As before, the address input buffer provides the true and complement versions of the address signals An and An, 62a and 62b, respectively, which may be provided to the predecoders. Unlike the above described address input path 60, however, this new address input path 80 includes a pulse generator 82 and individual ATD signal generator with disable capability 84. In one embodiment, each address input buffer 28 may have a corresponding pulse generator 82. while in other embodiments, a single pulse generator 82 may be associated with n address input buffers for memory device 10. Of course, in still other embodiments, a single pulse generator 82 may be included for each of m address input buffer 28, where there are a total of n/m groups of address input buffers 28 for the memory device 10.
Pulse generator 82 is triggered by the power-up signal 54 from the chip enable input buffer 46 to inhibit the potential individual address ATD pulse which might otherwise occur immediately after power-up of memory device 10. As discussed above. this individual address ATD signal may be produced as a result of the output of the address buffer 28 transitioning from the predetermined logic state, assumed during the power-down mode, to the true logic value of the corresponding input address. Without the use of pulse generator 82 (or equivalents thereof), or other schemes, as discussed below and contemplated within the scope of the present invention, such an address transition would otherwise occur even if the address itself was not changed while the memory device was in stand-by, merely because the logic value of the address may be opposite to the predetermined stand-by mode internal address value. As indicated, the number of pulse generators 82 used may be anywhere between 1 (for the entire memory device) up to the number of address inputs. The former case provides the advantage of a lower load for chip enable input buffer 46, while the latter tends to ensure a better delay match between the chip select path and address path of the memory device, for each individual address buffer 28. This delay matching of the address path tracks over changes in temperature, technologies, voltages, etc.
In operation, pulse generator 82 produces an ATD disable signal 86, which inhibits the production of the individual ATD signal 34. In one embodiment, ATD disable signal 86 is produced as a logical combination of a pair of signals as shown in FIG. 7. This pair of signals 88a and 88b are each developed from the power-up signal 54 provided by the chip enable input buffer 46. In this example, power-up signal 54 is provided to the input of an inverting delay 90, having an associated delay τ iD . The output of the inverting delay block 90 is provided to one input of a logic gate 92 (e.g., a NOR gate) as input signal 88a, and to the input of an inverting delay block 94 having an associated delay τ ND . The output of the inverting delay block 94 is the other input signal 88b to logic gate 92. Thus, as shown in FIG. 8, when the power-up signal 54 from the chip enable input buffer 46 transitions from a logic high to a logic low (e.g., signaling the beginning of a power-down mode for memory device 10), input signal 88a to logic gate 92 follows that transition after a delay τ iD associated with the inverting delay block 90. Of course, because of the action of the inverting delay block 90. input signal 88a is the logic inverse of power-up signal 54. Likewise, input signal 88b will follow the logic transition of power-up signal 54, but in this case such a transition is delayed by the combined time of τ iD and τ ND . The inverting delay block 94 may be implemented using an even number of logic inverters, and hence the logic state of input signal 88b will be the same as the logic state of power-up signal 54, as shown. Because of the logical NOR function provided by logic gate 92, there is no effect on the ATD disable signal 86 provided by the power-down transition. Thus, the regular activation of the global ATD signal may be expected as the chip enters the power-down mode. This takes place not only as a result of the address input buffers being forced to the power-down state, but mainly through the direct action of signal 50--which, in general, may be the same as the fast power-up signal 54--through the delay τ 2 provided by block 52, on the ATD combined block 36 in FIG. 1. It is required that the ATD combined block 36 provides an at-least same duration global ATD signal 38 pulse as a regular address transition, in order to ensure that perfect equalization is provided throughout memory device 10 during the power-down mode.
At power-up, however, when power-up signal 54 transitions from logic low to logic high, a difference is noted. In this case, input signal 88a follows the power-up transition after a time τ iD (the logic state of input signal 88a is opposite to that of power-up signal 54). Likewise, input signal 88b will follow the power-up transition after the time τ ND +τ iD associated with blocks 90 and 94. Thus, as shown in FIG. 8, there is a period of time during which both input signals 88a and 88b to logic gate 92 are logic low. Because of the action of logic gate 92, this will mean that the ATD disable signal 86 will be a logic high pulse. This pulse is the ATD disable signal 86 that is provided to the individual ATD signal generator with disable capability 84 and will ensure that no additional ATD signal is provided at the power-up transition. Hence, the start time and width of the ATD disable pulse 86 may be adjusted by adjusting τ iD and τ ND to provide desired start time and pulse width, respectively. Note, because the bit lines of memory device 10 were equalized during the power-down mode, as described above, no additional ATD signal is needed at power-up to ensure this equalization. Indeed, as discussed above, any such ATD signal would merely extend the access time unnecessarily, resulting in Tace being greater than Taa.
FIG. 9 now shows the details of one example of the individual ATD signal generator with disable capability 84. Notice that the true and complement address signals An and An, 62a and 62b, are provided to a transition detection pulse generator 94 as before. However, transition detection pulse generator 94 is also provided with the ATD disable signal 86 and includes disable capability not found in prior TDP generators. TDP generator 94 again produces output signal TDP which gates a pull-down transistor (e.g., an n-channel transistor) 96 to produce the individual ATD signal 34. However, when ATD disable signal 86 is active, output signal TDP is masked, thus preventing pull-down transistor 96 from providing an individual ATD signal 34.
To understand how this function is accomplished, refer to FIG. 10. As shown. TDP generator 94 includes delay blocks τ which may be activated into or out of the true and complement address signal path according to whether the address bit is transitioning from a logic high to logic low or logic low to logic high. The resulting signals are TDn and TDn, 98a and 98b, respectively. Signals TDn and TDn, are again provided as inputs to a logic gate 100 (e.g., a NOR gate) which provides signal TDP at its output. Unlike the prior TDP generator 66, however, TDP generator 94 includes disable capability. In the example, this disable capability is provided through the use of transistors 102 and 104. Transistors 102 and 104 are each gated by the ATD disable signal 86 such that when the ATD disable signal 86 is active (e.g., logic high) logic gate 100 is decoupled from its power source (Vcc) and output signal TDP is pulled low. Thus, in this example transistor 102 is a p-channel transistor coupled between the power source and the Vcc power terminal of the logic gate 100, and transistor 104 is an n-channel transistor coupled between the output of logic gate 100 and ground.
FIG. 11 shows the timing involved with these various signals and components of TDP generator 94. For convenience, the usually small propagation delay through the inactive delay block τ is not explicitly shown. As before, address signals An and An transition in response to a change in state of the address input signal 26. Thus, signals TDn and TDn follow, with one of these signals being delayed by a time τ. Ordinarily. that is with the TDP generator of the past, this would result in output signal TDP being produced (as shown in dotted outline). However, because of the action of ATD disable signal 86, which starts early enough and is of sufficient width to decouple logic gate 100 from its power source for at least the delay time a, the TDP output signal is masked and remains in a logic low state. Thus, transistor 96 is not switched on at the power-up transition and, as a result, no individual ATD signal 34 is generated. In operation this means that at the power-up time, no global ATD signal 38 will be produced and, as a result, no unnecessary extension of the bit line equalization period will be provided. Thus, Tace will be less than (or in a worst case equal to) Taa, and the timing parameters of memory device 10 are improved.
The present scheme thus ensures that no extra or unnecessary ATD signals are produced at power-up. In addition, the ATD combined circuit 36 will still activate the global ATD signal 38 at power-down, so as to ensure proper bit line equalization during the stand-by mode. Further, the row predecoders disable the wordlines during stand-by. as may also be true in some prior devices (e.g., as shown in dotted outline in FIG. 1). It should be noted that with such a solution, an earlier trailing edge of the ATD combined signal 38 may be experienced, which translates to an earlier sense amp enable. Thus, the sense amp enable timing should be correlated with the duration necessary to develop correct data on the bit lines after the wordline becomes active. That is, the signal developed on the bit lines when the sense amps are enabled should be similar for both Taa and Tace. An example of a possible mechanism for adjusting this timing is the delay circuit 52 in the chip enable input path driving the ATD combined block 36 as shown in FIG. 1.
In some cases, it may be impossible to ensure that power-down results in a global ATD signal 38 being developed to ensure proper equalization. Or, in other cases the row predecoders 30 of the memory device may not be provided with the capability of deactivating the wordlines in response to a power-down signal from the chip enable input buffer 46. In such cases, the above solution may be augmented by or replaced with an alternative solution. This same solution may be used in applications where address transitions at the memory device are not allowed to occur in stand-by later than in the vicinity of the power-down transition. Such a solution involves the use of a latched address input buffer 10, as shown in FIG. 12. The latched address input buffer 110 is capable of avoiding unnecessary internal address transitions at power-up, because the state of the address is stored prior to entering the power-down mode. Thus, during standby, rather than outputting a predetermined logic value the latched address input buffer 110 provides the true address value strobed a short time interval (e.g., as given by the propagation delay time between the chip enable input pin and the chip enable input buffer 46 output signal 54) after the stand-by command time instant. The fact that the logic value of the input is stored in such a way is important because this will reduce the probability of an undesired extended global ATD pulse 38 being produced. This happens, of course, because the true address value is stored and output by the latched address input buffers, rather than some predetermined address value, and thus there will be no input buffer output transition at power-up.
Latched address input buffer 110 includes an input buffer 112 which receives the address input signal 26 and the power-up signal 54 from the chip enable input buffer 46. The power-up signal 54 is also provided as the clock input for a storage device 114, which in this example is an edge-triggered D-type flip-flop. The triggering edge is actually the power-down transition of the fast power-up signal 54. Also, the fast power-up signal 54 is used as a select input for a multiplexer 116. In operation, as shown in FIG. 13, an active low chip enable signal 48 transition from a logic low to logic high indicates that the power-down mode is to be entered. This results in the power-up signal 54 being produced, after some delay associated with the chip enable input buffer 46. In accordance with its designation, as fast power-up signal 54, the power-up transition delay is drawn smaller than the power-down transition delay. If, during the time between the CE input 48 power-down transition and the associated logic transition of the power-up signal 54 the logic value of the address input 26 is switched, the new address will still be latched in the storage device 114. Then, during power-down as well as after power-up, this will be the output signal of multiplexer 116, if the logic value of the address input signal 26 does not change again. Latched address input buffer 110 may also include an inverting hysteresis stage 118, as is customary in the art.
A simplified implementation of the latched address input buffer scheme could be used by targeting only the functionality of the circuit illustrated in FIG. 12. Such a latched address input buffer 120 is illustrated in FIG. 14. It should be apparent that a level-triggered latch 122 which is clocked by the power-down transition of power-up signal 54 may be used to capture the address input 26 in the vicinity of a CE input 48 power-down transition. For example, as shown in timing diagram of FIG. 15, when the CE signal 48 transitions to indicate a power-down mode, the propagation delay time between the chip enable signal and the power-up signal 54 provides an opportunity to still capture the new logic state of the address input 26, in spite of its switching. Thus, the true address value is captured in storage device 122, and there will be no individual ATD signal generated at power-up.
It should also be noted that by using the ATD-inhibit solutions discussed above not only is Tace improved, but Tsce (i.e., a chip enable controlled write access timing parameter defining a period from CE going low to the end of the write) benefits as well. for memory devices that used ATD-gated bit line access (such as memory device 10 illustrated in FIG. 1). The relative improvement is shown in FIG. 16 and has to do with the time interval an internal write has available to access the bit lines. In the past, the access time interval began at a time instant A old , when the ATD combined signal (i.e., the global ATD signal, extended as a result of the delay through the CE buffer, and the subsequent individual ATDs, triggered by the addresses having the true value opposite to the power-down predetermined state) transitioned to a logic high (inactive state). The access time ended at a time instant A end , when (in the worst case) the address was switched simultaneously with the end of the write (THA=0). This presented an inherent drawback in that Tsce had to have a larger value than the Tpwe specification (the WE pulse width).
The proposed solutions now allow the write to access the bit lines earlier, at time A new , because the ATD that would otherwise have occurred as a result of the chip enable signal becoming active is inhibited. This provides an extended period of time for the write to be completed. Thus, Tsce is reduced, eliminating the need to have a larger Tsce (as compared to Tpwe) write parameter specification.
Thus, a scheme for inhibiting ATD signals at power-up in a memory device having a stand-by mode has been presented. As indicated at the outset of this description, although the scheme was illustrated by way of example through the use of the accompanying figures, the broader spirit and scope of the invention should only be measured in terms of the claims which follow. | In a memory device having a power-down mode, an address transition detection (ATD) signal within the memory device is inhibited at a power-up transition, provided that a power-down transition which proceeded the power-up transition ensured bit line equalization. The wordlines of the memory device may be disabled during the power-down mode and subsequently enabled (e.g., after an address-matched delay, to ensure a valid address is available for the first access following power-down) in response to the power-up transition. The ATD signal may be inhibited by generating a pulse having an appropriate starting time, and of sufficient duration to decouple an ATD pulse generator from dynamic bit line equalization control circuitry within the memory device. Such a pulse may be generated by combining a pair of signals produced in response to the power-up transition, at least one of the signals being delayed in time with respect to the other. In some cases, the ATD signal may be prevented by latching an address at the memory device, following an indication that the memory device is about to enter the power-down mode. | 6 |
This is a continuation-in-part application of Ser. No. 07/534,035, filed Jun. 6, 1990, now U.S. Pat. No. 5,008,087.
This invention relates to ozone generation using electrical discharges and more particularly to tubular type ozone generator apparatus and methods of ozone generation using such apparatus.
BACKGROUND OF THE INVENTION
Reference may be made to the following U.S. patents of interest: U.S. Pat. Nos. 3,214,364; 4,417,966; 3,967,131; 3,984,697; 4,504,446; 4,818,498; 4,234,800; 4,774,062; 4,954,321.
Ozone has been used as a disinfectant and oxidant in industrial, commercial, municipal and recreational water use for over 80 years. One technique for producing ozone uses elongated tubular electrodes concentrically spaced from each other with an elongated tubular dielectric member concentrically spaced in between the inner and outer electrodes. In some cases, the inner electrode may consist of a surface plating on the inside surfaces of the elongated dielectric member. A feed gas, such as air or oxygen is inserted at one end of the ozone generator and in the annular gap between the outer electrode and the dielectric member. Applying a high voltage between the electrodes creates a corona discharge of the gas through the dielectric member and thereby creates ozone.
Generally, a cooling water jacket surrounds the grounded outer electrode to provide cooling for the unit. The dielectric member is typically constructed of glass or ceramic material, tubular shaped, and is supported by spring members contacting the tubular outer glass surface between the electrodes.
The corona discharge between the electrodes creates a substantial amount of heat which not only can lead to cracks in the dielectric member, but also results in inefficient ozone generation. Thus, one of the problems inherent in the typical ozone generator herein discussed is failure of the electrode assembly due to cracks in the dielectric member. Hot spots in the glass at the support spring locations and other heat induced stresses cause cracks and burn throughs leading to eventual failure of the dielectric member. This results in equipment shutdown and requires costly and time consuming repairs of the unit.
In addition, the ozone which is formed during the discharge is subject to being destroyed if maintained in the discharge zone at temperatures greater than about 130° Farenheit (54° Centigrade). Therefore it is desired for maximum efficiency of ozone production to maintain the gas temperatures less than 130° Farenheit (54° Centigrade), and preferably between about 70°-90° Farenheit (21°-32° Centigrade). Some degree of cooling is afforded by the presence of the cooling water acting on the outer electrode, but this has a minor cooling effect on the dielectric member. Secondly, while there is some cooling afforded by the feed gas which is split for simultaneously traversing in one direction the annular gaps between the outer electrode and the dielectric member, and between the dielectric member and the inner electrode, inefficient ozone production and low operating life of the dielectric member limit the usefulness of prior ozone generators.
Accordingly, it is desired to provide improved ozone generator apparatus and methods of ozone generation featuring increased reliability and high ozone generation efficiency wherein the following problems of prior units and the operation thereof are reduced or eliminated:
1. Reducing the stress and hot spots on the dielectric member due to the heat build-up during corona discharge so as to extend the life of the electrode assembly; and
2. Increasing the efficiency of ozone production.
SUMMARY OF THE INVENTION
An improved tubular type ozone generator with reversing gas direction apparatus and method of operation is provided. An improved support for the dielectric member is provided which eliminates the need for support members between the inner and outer electrodes.
In accordance with one aspect of the present invention, there is provided a tubular type ozone generator unit with elongated inner and outer concentrically spaced electrodes and an elongated tubular dielectric member supportedly spaced between the electrodes with improved support means. Opposite ends of the tubular dielectric member extend beyond the inner electrode ends and are supported by insulating end support blocks. No spring support members are needed to support the dielectric member between the electrodes.
Means are provided for supplying a gas such as air under pressure to the annular inner gap between the inner electrode and the dielectric member such that all of the gas traverses from a first gas feed end of the ozone generator to the opposite gas return end so as to produce ozone and also cool the inner surface of the dielectric member. At the opposite end, sealing means are provided to reverse the flow of ozone and feed gas and to direct it into the annular outer gap between the dielectric member and the outer electrode to produce more ozone. All of the gas is passed back to its starting point at the gas feed end of the ozone generator and the developed ozone can be collected from a suitable outlet at that point. The reversing gas flow cools the outer surface of the dielectric member to desirably reduce the temperature differential between the inside and the outside of the dielectric thereby reducing the stress on the dielectric member and extending the life of the electrode assembly.
It has been found that using the total gas flow in one direction first to develop ozone and to cool off the inside surface of the dielectric member and then reversing all of the gas to the opposite direction to develop more ozone and cool off the outside surface of the dielectric, as well as eliminating the spring support members between the electrodes, provides a resulting reduction in temperature differential between the inside and outside surfaces of the dielectric and eliminates hot spots and stresses--which leads to a significant increase in dielectric reliability.
Additionally, it has been found that the reversing gas direction apparatus and method of the present invention results in an increased production of ozone output and concentration of about 50% or more compared to prior units due to an increase in the effective surface area of the dielectric. Thus, increased ozone output and concentration are achieved without increasing the number of electrodes in order to obtain a desired ozone output. If desired, a plurality of tubular type ozone generators according to the invention can be coupled together in the same cabinet with suitable input and output gas manifolds.
In an alternative embodiment of the invention, a hollow inner electrode is provided and the feed gas is supplied to the interior at one end of the inner electrode with the gas efficiently cooling the inside surface of the inner electrode. Then, as in the first embodiment, the gas direction is reversed to cool both the inner and outer surfaces of the dielectric. The gas traverses the annular inner gap between the inner electrode and the dielectric member towards one end of the electrode assembly where sealing means are provided to again reverse the direction of the gas so that all of the gas traverses the annular outer gap between the dielectric member and the outer electrode and arrives at the opposite end where the ozone may be removed through a suitable outlet port.
In a preferred hollow inner electrode embodiment, the feed gas inlet and the ozone outlet are at opposite ends of the ozone generator. The feed gas is coupled from an inlet, preferably at the top of the ozone generator, through electrode and dielectric support means to the top of the inner electrode for conveying gas under pressure to the inner electrode interior. An opposite apertured end wall in the electrode enables the feed gas to exit the electrode interior at the bottom end, reverse direction and traverse upwardly in the inner space between the inner electrode and the dielectric member. At the ozone generator top end the gas passes through an apertured end cap supporting the dielectric member, reverses direction and traverses downwardly in the outer space between the dielectric member and the outer electrode to exit the ozone outlet at the bottom.
An insulating support rod extends through the apertured end cap and is mounted to the ozone generator support frame and to the top of the inner electrode to communicate the feed gas through a passageway from a gas inlet port to the hollow interior of the inner electrode and to support the inner electrode and the dielectric member. A support insulator assembly at the ozone generator bottom end supports the dielectric member and the inner electrode and forms a reversing input gas chamber feeding gas to the inner space to develop ozone, while also forming an ozone outlet chamber for receiving ozone from the outer space. The support insulator assembly includes a ceramic plug portion to inhibit high voltage breakdown of the insulator in the space between the grounded support frame and a high voltage conductor connection to the inner electrode. A bleed hole in the support insulator assembly permits any contaminant buildup in the inner space between the inner electrode and the dielectric member to exit the inner space so as to prevent degrading the quality of the developed ozone.
In all of the embodiments the input and output ports may be reversed so that the feed gas may be supplied to the original output port and the resulting ozone concentrated gas may be withdrawn from the original input port.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of this invention which are believed to be novel are set forth with particularity in the appended claims. The invention may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements in the several figures and in which:
FIG. 1 is a longitudinal cross-sectional fragmented view of a tubular type ozone generator constructed in accordance with the principles of the present invention;
FIG. 2 is a cross-sectional view taken along section lines 2--2 of FIG. 1;
FIG. 3 is a cross-sectional view taken along section lines 3--3 of FIG. 1;
FIG. 4 is a longitudinal cross-sectional fragmented view illustrating an alternative embodiment of the invention;
FIG. 5 is a schematic view illustrating a plurality of ozone generators according to the invention located in a single cabinet enclosure;
FIG. 6 is a schematic view illustrating the plurality of ozone generators of FIG. 5 joined together with input and output manifolds;
FIG. 7 is a longitudinal cross-sectional fragmented view illustrating another alternative embodiment of the invention; and
FIG. 8 is a schematic view illustrating a plurality of ozone generators of FIG. 7 joined together with input and output manifolds.
DETAILED DESCRIPTION
Reference may be made to the drawings wherein there is illustrated a tubular type ozone generator 10 which includes a high voltage electrode assembly for generating ozone from a feed gas comprising an elongated inner electrode 12 spacially separated from an elongated tubular outer electrode 14 with an elongated tubular dielectric member 16 therebetween. Electrodes 12, 14 are formed of stainless steel. Dielectric member 16 is formed of a glass dielectric material, such as borosilicate.
The electrodes and the dielectric member are mounted in a housing 18 so that there is an elongated annular inner gap 20 between inner electrode 12and dielectric member 16 and an elongated annular outer gap 22 between dielectric member 16 and outer electrode 14. Housing 18 may be formed of an aluminum extrusion in the form of an elongated cylindrical member with a plurality of support legs 24.
As shown in FIG. 2, the diameter of housing 18 is much larger than the diameter of outer electrode 14 so as to form a gap 26 for a cooling water jacket around the electrode assembly. A cooling water inlet 28 is providedat one end of housing 18 for supplying cooling water to gap 26 and outer electrode 14 so that the water can cool the outer electrode and exit through a cooling water outlet 30. Respective housing end caps 32, 34 are provided at opposite ends of the housing with suitable O-ring seals to seal the ends of housing 18 to the respective ends of the outer electrode and thereby maintain the cooling water within gap 26.
At the gas feed end of the ozone generator, there is provided a support rod36 formed of an insulating material and with one threadable end 38 for threadably engaging inner electrode 12 and an opposite end which extends through a support frame 40. Support frame 40 also forms a gas sealing end cap at one end of the ozone generator and includes a spacer tube 42 mounted with suitable O-rings to end cap 32 at one end and to a sealing support plate 44 at the other end. Support plate 44 includes an aperture 46 adapted to accommodate support rod 36. A lock washer and mounting nut combination 48 threadably engage the end of rod 36 to maintain inner electrode 12 supportedly mounted at one end and within housing 18.
Rod 36 includes an air or gas inlet 50 coupled to an elongated passageway 52 and four transverse passageways 54 leading to an annular antechamber 56. Antechamber 56 is bounded within a dielectric member end extension 58,with inner electrode 12 at one end and a support/sealing block 60 supporting extension 58 at the other end. As seen in FIG. 1, the end of extension 58 is inserted into an annular groove 59 with an O-ring seal in block 60. Aperture 61 in block 60 is adapted to snugly fit on support rod 36 so as to supportedly mount dielectric member 16 at one end and within housing 18. Gas inlet 62 leads the input gas in antechamber 56 to inner gap 20 between inner electrode 12 and dielectric member 16 to develop ozone in gap 20.
At the opposite gas return end of the electrode assembly, a dielectric member end extension 64 is supportedly mounted in housing 18 by an apertured end cap 66 mounted to extension 64 similar to the mounting of block 60 on extension 58. Cap 66 includes an aperture 65 and an annular groove 67 for receiving the end of extension 64. Both block 60 and cap 66 are formed of insulating material, such as an elastomeric resin.
Cap 66 also includes a plurality of apertures 68 (see FIG. 3) to enable thefeed gas in inner gap 20 to exit through apertures 68 and enter a gas return chamber 70. The total area of apertures 68 is sized to be much larger than the area of gas inlet 50 so there is no restriction in the gaspassing through apertures 68 and entering chamber 70.
Gas return chamber 70 is formed by a support frame 72 similar to support frame 40 and includes a spacer tube 74 and an end plate 76 with suitable O-ring seals for sealing the respective end of the electrode assembly and defining gas return chamber 70 at the electrode assembly gas return end. In addition, end plate 76 includes aperture 78 which is adapted to receivean insulating rod 80 having a center conductor rod 82 threadably engaging inner electrode 12 at one end and having a high voltage terminal 84 at theother end.
Gas return chamber 70 has an annular passageway 86 which communicates chamber 70 with outer gap 22 between dielectric member 16 and outer electrode 14 so that the produced ozone and feed gas reverses direction and traverses the length of the electrode assembly from the gas return endback to the gas feed end. Further ozone production is of course obtained ingap 22. At the opposite gas feed end of the electrode assembly, outer gap 22 ends in a second annular passageway 88 which couples the ozone developed in gaps 20 and 22 along with the remaining feed gas into an ozone outlet chamber 90 defined within support frame 40. An ozone-gas outlet port 92 in spacer tube 42 enables the ozone collected in outlet chamber 90 along with the remaining feed gas to exit the ozone generator for storage and use.
Electrical power to the ozone generator 10 is controlled by a variable-voltage, high reactance transformer. A high voltage transformer is used to increase the primary voltage of 110 VAC or 220 VAC, 50/60 Hz tothe 7,000-15,000 volts required for ozone production. One end of the outputof the high voltage transformer is connected to terminal 84 and the other end is securely attached to housing 18 through which the outer electrode is grounded.
Reversing of the feed gas between inner gap 20 and outer gap 22 has been found to significantly increase the ozone production and the useful life of the electrode assembly. It is believed that these unexpected results are due to the more efficient cooling of both the inner and the outer surfaces of the dielectric member to reduce the temperature differential between these surfaces. In addition the unexpected results are believed due to the technique of passing all of the feed gas initially through inner gap 20 to enable ozone production, and then reversing the gas flow and passing the entire combination of developed ozone and feed gas throughouter gap 22 to develop a much larger amount of ozone than is attained in astandard one-time through unit or even in a split gas, one-time through unit.
In a constructed embodiment of the invention, the following physical dimensions and operating values resulted in the following indicated ozone output production:
Length of electrodes 12 and 14--273/4 in. (70.5 cm)
Length of dielectric member 16--291/2 in. (74.9 cm).
Outer diameter of electrode 12--1.25 in. (3.18 cm).
Inner diameter of electrode 14--1.70 in. (4.32 cm).
Width of inner gap 20--0.100 in. (2.54 mm).
Width of outer gap 25--0.166 in. (4.22 mm).
Eight Apertures 68 in cap 66, each 0.140 in. diameter (3.56 mm) for a totalaperture area of 0.123 sq.in. (79.36 sq.mm).
Inlet 50--0.25 in. diameter (6.35 mm) for a total inlet area of 0.049 sq.in. (31.62 sq.mm).
Four passageways 54, each 0.156 in. diameter (3.96 mm).
Magnetic high reactance transformer with 14,000 volts between electrodes 12, 14.
Input air flow--0.167 CFM (5.09 CCM).
Output ozone--21 gms/cm or 5.9 gms/hour.
An alternative embodiment 93 of the present invention is illustrated in FIG. 4. Notice that this embodiment utilizes the same aspect of the invention involving reversing of the total air flow between the inner electrode and the dielectric member and between the dielectric member and the outer electrode as in the first embodiment. However, in the embodimentof FIG. 4, electrode 94 is hollow and is threadably mounted to an insulating support rod 96 at the gas feed end. This permits gas through inlet 98 to enter passageway 100 of rod 96 and thereby communicate with a passageway 102 in a conduit 104 which is supportedly mounted within annular recess 105 in rod 100 at the gas feed end.
The feed gas is conveyed through conduit 104 to the opposite first gas return end of the electrode assembly where conduit end 105 is open to enable the feed gas to enter the hollow inner electrode interior 106. The feed gas therefore reverses direction and traverses the interior 106 of electrode 94 from the first gas return end back to the gas feed end to cool the inner electrode more efficiently.
At the gas feed end of electrode 94, apertures 108 are provided for reversing the gas flow so that the gas passes out of the interior 106 of electrode 94 and into antechamber 105 formed by sealing block 107. Block 107 also supports one end of the dielectric member on rod 96.
The feed gas now is directed to inner gap 110 between inner electrode 94 and dielectric member 112 to produce further ozone in gap 110. As in the first embodiment, the gas traverses the length of inner gap 110, exits through an apertured, dielectric member supporting end cap 111 at the second gas return end of the electrode assembly, again reverses direction and traverses outer gap 114 between dielectric member 112 and outer electrode 116 on its way to the gas feed end of the electrode assembly. The ozone produced in gaps 110 and 114 along with the remaining gas then exits through a suitable outlet port 92. This reversing of the total feed gas between inner gap 110 and outer gap 114 enables a higher ozone production and a more efficient cooling of both surfaces of the dielectricmember. A water jacket may be provided for this embodiment as illustrated similar to that illustrated and described for the first embodiment.
Therefore, both of the above-described embodiments provide a total gas flowtraversing the inner gap between the inner electrode and the dielectric member, reversing direction and traversing the outer gap between the dielectric member and the outer electrode. The significant advantage of this total gas reversing technique is that ozone is produced in both directions with the total gas flow. Thus, more feed gas is utilized in thedischarge zones between the electrodes to produce more ozone than in prior devices, while also permitting the total gas flow to enable more efficientcooling of the electrode assembly. This unique apparatus and method provides a significant improvement in ozone production over prior available units.
Rather than initially passing the gas from the inner gap and then to the outer gap, it is possible to reverse this sequence. Accordingly, one may initially pass the feed gas through the outer gap between the outer electrode and the dielectric member and then reverse the gas direction andpass the feed gas between the inner gap formed between the dielectric member and the inner electrode. As in the illustrated embodiment of the invention herein, ozone from the total gas will be produced in both gaps. However, it is not believed that the best electrode assembly cooling conditions will be attained in this alternative outer-inner gap embodiment. Thus, the illustrated embodiments of the invention in FIGS. 1-4 herein with the gas passing first from the inner gap and then to the outer gap is the preferred configuration.
Referring now to FIGS. 5 and 6, there is schematically illustrated a combination of several ozone generators 120 which can be comprised of either the generator 10 of FIGS. 1-3 or the generator 93 of FIG. 4. Each of the ozone generators 120 are suitably mounted within a cabinet 122. FIG. 6 illustrates an intake manifold 124 for coupling a feed gas such as air to the respective feed gas input lines 126. Similarly, an output manifold 128 receives the respective ozone concentrated gas from each ozone output line 130 so that the total output ozone from manifold 128 comprises the total ozone produced by combining the outputs of ozone generators 120.
An alternative hollow inner electrode embodiment 132 of the present invention is illustrated in FIG. 7. This embodiment utilizes the same aspect of the invention involving reversing of the total air flow between the inner electrode and the dielectric member and between the dielectric member and the outer electrode as in the embodiments of FIGS. 1-3 and of FIG. 4, and is similar in many respects to the hollow inner electrode embodiment of FIG. 4. Thus, in the embodiment 132 of FIG. 7, feed gas is inserted in the inner gap 110 between a hollow inner electrode 134 and a dielectric member 112, exits the inner gap, reverses direction, and traverses the outer gap 114 between dielectric 112 and outer electrode 116to issue from ozone outlet port 136.
In the preferred embodiment 132 of FIG. 7, the ozone generator is arranged vertically with feed gas inlet 98 at the top and ozone outlet port 136 at the bottom. Feed gas passes through passageway 100 directly into the interior 138 of the inner electrode. An apertured end cap 140 is sealably mounted to and supports dielectric member 112. End cap 140 includes central aperture 142 for accommodating insulating support rod 96 and also includes a plurality of apertures 143 for enabling gas in inner gap 110 toexit, reverse direction and enter into outer gap 114.
The input feed gas at the top of inner electrode 134 is passed into the hollow interior 138 and traverses downwardly towards the bottom of the interior so as to exit from inner electrode apertured closure wall 144 having apertures 146. At the bottom end of the ozone generator, there is provided a support insulator assembly which includes a dielectric support insulator 148 and a high voltage insulator 150.
Dielectric support insulator 148 is sealably mounted to dielectric member 112 and to the inner electrode apertured closure wall 144 so as to define an input gas chamber which reverses the direction of the feed gas exiting through apertures 146 and directs the feed gas to inner gap 110. The dielectric support insulator 148 also is sealably mounted to end plate 77 of the support frame 72 at the ozone generator bottom end so as to define an ozone outlet chamber 152. Dielectric support insulator 148 further includes an elongated central aperture adapted to accommodate center conducting rod 82 for supporting the inner electrode at the bottom ozone generator end.
High voltage insulator 150 is formed of ceramic material and includes a protruding plug portion 154 sized to enter into snug-fit engagement withina cavity of dielectric support insulator 148. It is preferred that high voltage insulator 150 be formed of a suitable material having high voltageelectrical insulating properties, such as ceramic. Therefore, ceramic plug portion 154 suitably electrically insulates the high voltage present between conducting rod 82 and end plate 77 so as to inhibit voltage breakdowns which might otherwise occur.
In the preferred configuration of embodiment 132, the feed gas is supplied to the top of the ozone generator, such as schematically illustrated in FIG. 8 wherein there is shown a combination of several ozone generators 132. In this preferred configuration, any contaminants within inner gap 110 may accumulate during ozone generation and tend to collect at the bottom of dielectric 112, adjacent support insulator 148. A bleed hole 156is provided through support insulator 148 to communicate with inner gap 110so as to eliminate any contaminant buildup inside dielectric 112. As indicated with the prior embodiments, rather than initially passing the gas from the inner gap and then to the outer gap, it is possible to reverse this sequence, however the illustrated embodiment shown in FIG. 7 is the preferred configuration.
In the operation of the preferred embodiment of FIG. 7, feed gas at inlet 98 is coupled through passageway 100 into interior 138 of the inner electrode and proceeds downwardly to the bottom end while cooling the inner electrode. The feed gas now exists through apertures 146, reverses direction and passes upwardly through inner gap 110 to produce ozone and to cool the dielectric member. Passing out through apertures 143 the gas reverses direction, enters outer gap 114, and passes downwardly to generate more ozone and to cool the dielectric member, finally collecting at ozone outlet chamber 152 for exiting out the ozone outlet port 136.
The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as modifications will be obvious to those skilled in the art. | A tubular type ozone generator with inner and outer concentric electrodes and a middle dielectric member. One end is sealed to permit feed gas traversing the inner gap between the inner electrode and the dielectric member to reverse direction and to traverse the outer gap between the dielectric member and the outer electrode. A method for producing ozone using a tubular type ozone generator where first the total feed gas is passed in one direction between an electrode and the dielectric member for producing ozone, reversed, and then passed in the reverse direction between the dielectric member and the other electrode producing additional ozone. A hollow inner electrode permits more efficient cooling of the inner electrode. A plurality of ozone generators are combined with intake and output manifolds for the feed gas and produced ozone. | 2 |
TECHNICAL FIELD
[0001] The present disclosure relates generally to parametric audio systems. More particularly, some embodiments relate to inductive devices employed with ultrasonic emitters.
DESCRIPTION OF THE RELATED ART
[0002] Non-linear transduction results from the introduction of sufficiently intense, audio modulated ultrasonic signals into an air column. Self-demodulation, or down-conversion, occurs along the air column resulting in the production of an audible acoustic signal. This process occurs because of the known physical principle that when two sound waves with different frequencies are radiated simultaneously in the same medium, a modulated waveform including the sum and difference of the two frequencies is produced by the non-linear (parametric) interaction of the two sound waves. Parametric audio reproduction systems produce sound through the heterodyning of two acoustic signals in a non-linear process that occurs in a medium such as air. The acoustic signals are typically in the ultrasound frequency range. The non-linearity of the medium results in acoustic signals produced by the medium that are the sum and difference of the acoustic signals. Thus, two ultrasound signals that are separated in frequency can result in a difference tone that is within the 60 hz to 20,000 Hz range of human hearing.
[0003] While the theory of non-linear transduction has been addressed in numerous publications, commercial attempts to capitalize on this intriguing phenomenon have largely failed. Most of the basic concepts integral to such technology, while relatively easy to implement and demonstrate in laboratory conditions, do not lend themselves to applications where relatively high volume outputs are necessary. As the technologies characteristic of the prior art have been applied to commercial or industrial applications requiring high volume levels, distortion of the parametrically produced sound output has resulted in inadequate systems. Whether the emitter is a piezoelectric emitter or PVDF film or electrostatic emitter, in order to achieve volume levels of useful magnitude, conventional systems often required that the emitter be driven at intense levels. These intense levels have often been greater than the physical limitation of the emitter device, resulting in high levels of distortion or high rates of emitter failure, or both, without achieving the magnitude required for many commercial applications.
[0004] Efforts to address these problems include such techniques as square rooting the audio signal, utilization of Single Side Band (“SSB”) amplitude modulation at low volume levels with a transition to Double Side Band (“DSB”) amplitude modulation at higher volumes, and recursive error correction techniques. While each of these techniques has proven to have some merit, they have not separately, nor in combination, allowed for the creation of a parametric emitter system with high quality, low distortion, and high output volume. The present inventor has found, in fact, that under certain conditions some of the techniques described above actually cause more measured distortion than does a refined system of like components without the presence of these prior art techniques.
SUMMARY
[0005] Embodiments of the technology described herein include a pot core inductive device for use in ultrasonic audio systems. Although the embodiments are discussed in regards to ultrasonic audio systems, the embodiments are applicable for use in any system requiring an inductive device; particularly systems where electrical resonance is important for optimal performance. In various embodiments, the device includes a non-conductive or ferromagnetic housing composed of an iron or ferrite material and comprising two sections, a coil support member, a coil structure, and an elastomeric material. The two sections of the housing are configured to define a cavity within the housing. The coil support member and elastomeric material are disposed within the cavity. The device also comprises an adjustment mechanism configured to adjust an air gap, formed between the two sections of the housing, to achieve an optimal or near optimal inductive value. An adjustable means for securing the two halves may also be present.
[0006] Other features and aspects of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the features in accordance with embodiments of the invention. The summary is not intended to limit the scope of the invention, which is defined solely by the claims attached hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The present invention, in accordance with one or more various embodiments, is described in detail with reference to the following figures. The drawings are provided for purposes of illustration only and merely depict typical or example embodiments of the invention. These drawings are provided to facilitate the reader's understanding of the invention and shall not be considered limiting of the breadth, scope, or applicability of the invention. It should be noted that for clarity and ease of illustration these drawings are not necessarily made to scale.
[0008] Some of the figures included herein illustrate various embodiments of the invention from different viewing angles. Although the accompanying descriptive text may refer to such views as “top,” “bottom,” or “side” of an apparatus, such references are merely descriptive and do not imply or require that the invention be implemented or used in a particular spatial orientation unless explicitly stated otherwise.
[0009] FIG. 1 is a diagram illustrating an ultrasonic sound system suitable for use with the inductive device described herein.
[0010] FIG. 2 is a diagram illustrating an amplifier and emitter system utilizing a pot core inductive device in accordance with an embodiment of the technology disclosed herein.
[0011] FIG. 3 is a diagram illustrating an amplifier and transducer system utilizing a pot core inductive device in accordance with an embodiment of the technology disclosed herein.
[0012] FIG. 4 is a diagram illustrating an amplifier and transducer system utilizing a pot core inductive device in accordance with an embodiment of the technology disclosed herein.
[0013] FIG. 5 is a cross-sectional view of a typical pot core structure.
[0014] FIG. 6 is a flow diagram illustrating a method of optimizing a parametric transducer system in accordance with an embodiment of the technology disclosed herein.
[0015] FIG. 7 is a cross-sectional view of a pot core inductive device in accordance with an embodiment of the technology disclosed herein.
[0016] FIG. 8 is a diagram illustrating an exploded view of a pot core inductive device in accordance with an embodiment of the technology disclosed herein.
[0017] FIG. 9 is a diagram illustrating a pot core structure in accordance with an embodiment of the technology disclosed herein.
[0018] FIG. 10 is a diagram illustrating an assembled pot-core conductor in accordance with one embodiment of the technology disclosed herein.
[0019] FIG. 11 is a diagram illustrating an assembled pot-core conductor in accordance with one embodiment of the technology disclosed herein.
[0020] The figures are not intended to be exhaustive or to limit the invention to the precise form disclosed. It should be understood that the invention can be practiced with modification and alteration, and that the invention be limited only by the claims and the equivalents thereof.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0021] The present disclosure represents an improvement on a transducer system for use in ultrasonic audio production described in U.S. Pat. No. 8,391,514, issued Mar. 5, 2013 to the present inventor, which is herein incorporated by reference. Transducers convert a signal from one form of energy to another. In ultrasonic audio production, an audio system comprises an amplifier, processor circuitry, an inductive device, and an emitter coupled in an electrical circuit to convert an electrical signal into an acoustic signal, or sound. As discussed above, the present inventor discovered that many of the conventional methods for increasing the output of an ultrasonic emitter created greater distortion in the resultant audio signal. This distortion makes creation of a high quality parametric audio system difficult.
[0022] The present inventor discovered that by redesigning the transformer, electrical resonance could be achieved between an inductive device and an emitter, increasing the accuracy of the match between the electronic circuits and the emitters, thus eliminating much of the distortion resulting from physical limitations of conventional transducer devices. In one embodiment of the invention of U.S. Pat. No. 8,391,514, the invention utilized an inductive device housed within a pot core structure. Use of a pot core allowed for the inductive device to be physically located closer to the emitter, allowing the system to operate at a more efficient level by reducing the interference of the magnetic field of the inductive device with the emitter. At the same time, physically locating the inductive device closer to the emitter reduced the need for long runs of high voltage wiring to couple the inductive device to the emitter.
[0023] Although the patented design allowed for the production of a higher quality ultrasonic audio signal, the conventional design of a pot core structure limited the ability to fine-tune the resonant circuit for optimal audio output. The improvements described herein can be configured to provide a more responsive transducer to achieve the optimal output audio signal.
[0024] FIG. 1 illustrates a non-limiting signal processing system 10 that may be used with an embodiment of the invention. In this embodiment, various processing circuits or components are illustrated in the order (relative to the processing path of the signal) in which they are arranged according to one implementation. It is to be understood that the components of the processing circuit can vary, as can the order in which the input signal is processed by each circuit or component. The processing 10 can include more or fewer components or circuits than those shown.
[0025] A stereo audio signal enters the signal processing system 10 through audio inputs 12 a , 12 b . The source of the audio signal may be a microphone, memory, a data storage device, streaming media source, CD, DVD or other audio source. The audio content may be decoded and converted from digital to analog form, depending on the source. Equalizing networks 14 a , 14 b provide equalization of the signal. The equalization networks can, for example, boost or suppress predetermined frequencies or frequency ranges to increase the benefit provided naturally by the emitter/inductor combination of a transducer device.
[0026] Compressor circuits 16 a , 16 b compress the dynamic range of the incoming signal, effectively raising the amplitude of certain portions of the incoming signals and lowering the amplitude of certain other portions of the incoming signals. More particularly, compressor circuits 16 a , 16 b can be included to narrow the range of audio amplitudes. In one aspect, the compressors lessen the peak-to-peak amplitude of the input signals by a ratio of not less than about 2:1. Adjusting the input signals to a narrower range of amplitude can be done to minimize distortion, which is characteristic of the limited dynamic range of this class of modulation systems. The order of the compression and equalization circuits can be reversed.
[0027] Low pass filter circuits 18 a , 18 b can be included to provide a cutoff of high portions of the signal. High pass filter circuits 20 a , 20 b can provide a cutoff of low portions of the audio signals. The high pass filters 20 a , 20 b can be configured to eliminate low frequencies that, after modulation, would result in deviation of carrier frequency (e.g., those portions of the modulated signal that are closest to the carrier frequency). Also, some low frequencies are difficult for the system to reproduce efficiently and, as a result, much energy can be wasted trying to reproduce these frequencies. The low pass filters 18 a , 18 b can be configured to eliminate higher frequencies that, after modulation, could result in the creation of an audible beat signal with the carrier.
[0028] After passing through the low pass and high pass filter circuits, modulators 22 a , 22 b modulate the audio signals with a carrier signal generated by oscillator 23 . Use of a single oscillator to drive both modulators 22 a , 22 b allows an identical carrier frequency to be used for multiple channels, lessening the risk that any audible beat frequencies may occur. High pass filters 27 a , 27 b can be used to pass the modulated ultrasonic carrier signal to filter out remaining unwanted signals below a certain frequency. The resultant signal then reaches the amplifier through signal processing system outputs 24 a , 24 b.
[0029] FIG. 2 is a diagram illustrating an amplifier and emitter system utilizing a pot core inductive device in accordance with an embodiment of the technology disclosed herein. Referring now to FIG. 2 , the diagram illustrates an amplifier 26 a , a pot core inductor 28 a (configured as a transformer in this example), and an ultrasonic emitter 3 a four one channel of the audio system. Many conventional systems utilize a transducer system with an inductive device oriented in series with the emitter. The disadvantage to this arrangement is that such a resonant circuit must necessarily cause wasted current to flow through the inductor. The emitter 30 a will perform best at—or near—the point where electrical resonance is achieved in the circuit. The amplifier (e.g., amplifier 26 a in FIG. 2 ), however, introduces changes in the circuit, which can vary based on factors including temperature, signal variance, and system performance. These effects make it more difficult to achieve and maintain stable resonance in the circuit when an inductor is coupled in series with the emitter 30 a ( FIG. 2 ).
[0030] A variety of inductive devices are known to those having ordinary skill in the art. Physical limitations of inductive devices, however, cause difficulties in a conventional parametric system. Inductive devices generate magnetic fields, which may “leak” beyond the confines of the inductor. Accordingly, they may interfere with the operation and response of a parametric emitter if positioned in proximity thereto.
[0031] For at least these reasons, most conventional parametric systems physically locate the inductive device a considerable distance from the emitter. This distance between the inductive device and the emitter requires longer wires for connecting the inductive device and emitter. A significant complication resulting from this physical limitation arises from the fact that a high voltage is generally required to carry the signal from the inductive device to the emitter. In certain installations, long “runs” of high voltage wiring may be necessary, which can be dangerous and interfere with communication systems not related to the transducer.
[0032] The relationship between the amplifier and the emitter adds an additional obstacle to designing an optimized and efficient transducer. Generally, the higher a frequency that is processed by an amplifier, the higher impedance at which the amplifier is best suited to operate. In the present case, the impedance experienced by the amplifier is the result of the load introduced by the inductive device and emitter pair, and by the overall transducer. In the case of parametric sound production, the operative signal is generally in the range of 40 kHz or greater. Amplifiers working with frequencies in this range generally operate more optimally when experiencing load impedances on the order of 8-12 Ohms.
[0033] To account for this, it would be desirable to match the resonance of the inductive device and emitter pair to improve the performance of the system. Limited available parametric emitter designs, however, hinder the ability to adjust the load presented by the inductive device and emitter pair. This, in turn, hinders the ability to obtain optimum resonance between the inductive device/emitter pair without adversely affecting performance of the unit as a whole.
[0034] The present inventor discovered and invented several amplifier and emitter systems utilizing an inductive device coupled in parallel with the emitter. Exemplary systems are described in detail in U.S. Pat. No. 8,391,514, which is incorporated herein by reference in its entirety. By configuring the inductive device in parallel with the emitter, the current circulates through the inductive device and emitter, as represented by circulating current path 40 in FIG. 2 . Such a configuration results in more stable and predictable performance of the emitter, and significantly less power being wasted as compared to conventional series resonant circuits.
[0035] Use of a “pot core” to house the inductive device further alleviates the need for the inductive device to be physically located a distance from the emitter. It is possible to capitalize on the characteristics of a pot core structure to create achieve electrical resonance in the inductive device/emitter circuit, while simultaneously achieving sufficient impedance for optimal operation of the amplifier. Although not optimal, use of a pot core inductive device in accordance with the present invention may also be coupled in series with the emitter.
[0036] FIG. 5 illustrates a cross sectional view of one embodiment of a pot core structure in accordance with the technology described in U.S. Pat. No. 8,391,514. The inset at the bottom right of the drawing illustrates an external view of the 2 halves shown in the example of FIG. 5 .
[0037] Two ferrite halves 50 , 51 define a cavity 52 within which an inductive device is disposed. Current passing through the inductive device generates a magnetic field, which could interfere with the functionality of the emitter. The ferrite material of the pot core halves 50 , 51 serves to contain this magnetic field so that it does not “leak” into the system and cause distortion. Although ferrite is the most common material for pot core structures, the structure may be composed of other materials, such as vitreous metal, carbonyl iron, laminated silicon steel, or any other material capable of shielding magnetic fields. The selection of the pot core material depends on a number of factors, including but not limited to the geometry of the core, the potential size of the air gap, and the permeability of the material chosen.
[0038] The two halves 50 , 51 each comprise and outer wall 53 a , 53 b which substantially encloses the inductive device, and an inner wall 53 b , 54 b . An air gap 55 between the inner walls 53 b , 54 b increases the permeability of the pot core: the larger the air gap 55 , the greater the permeability. The number of windings of the inductive device (wound about the core formed by inner walls 53 b , 54 b ) required to maintain the same inductance, however, increases with the size of the air gap 55 . At the same time, this greater number of windings increases the impedance of the system. Therefore, by adjusting the air gap 55 in the pot core, one can maintain the same inductance to achieve electrical resonance with the emitter while simultaneously increasing the load seen by the amplifier, i.e. increasing the impedance of the system.
[0039] FIG. 2 illustrates one embodiment of a transducer system disclosed in U.S. Pat. No. 8,391,514 and applicable for use with an embodiment of the present invention. Signal processing system outputs 24 a , 24 b are coupled to an amplifier 26 a . After amplification, the signal is delivered to an inductive device/emitter assembly 32 a . The emitter 30 a is operable at ultrasonic levels. The inductive device 28 a is coupled in parallel with the emitter 30 a . The inductive device 28 a in this embodiment is an inductor element held within a pot core.
[0040] FIG. 3 illustrates another embodiment of a transducer system disclosed in U.S. Pat. No. 8,391,514, wherein a transformer configuration is employed. The transformer 39 comprises a pair of inductor elements. The inductor element, or winding, 42 serves as the primary winding of the transformer and is connected to the amplifier 26 a . The inductor element, or winding, 41 serves as the secondary winding of the transformer and is connected to the emitter 30 a . As current passes through the primary winding 42 a voltage is induced in the secondary winding 41 . In one embodiment, both the primary and secondary windings are contained within the pot core.
[0041] FIG. 4 illustrates another embodiment, wherein the primary and secondary windings are combined in what is commonly known as an autotransformer 39 ′, showing the secondary winding 41 ′ and the primary winding 42 ′ contained in a single winding. The operation and function of an autotransformer will be readily appreciated by one of ordinary skill in the art having possession of this disclosure. The autotransformer can be configured such that its windings can easily be contained within the pot core.
[0042] The use of a step-up transformer provides additional advantages to the present system. Because the transformer “steps-up” from the direction of the amplifier to the emitter, it necessarily “steps-down” from the direction of the emitter to the amplifier. The step-down process, minimizing the effect of any such event on the amplifier and the system in general, therefore reduces any negative feedback that might otherwise travel from the inductor and emitter pair to the amplifier.
[0043] The characteristics and dimensions of the pot core structure and inductive device utilized in U.S. Pat. No. 8,391,514 can be determined in accordance with the exemplary method of optimizing a parametric system illustrated in FIG. 6 . The method is applicable with the presently disclosed technology, as well. The first step 60 is determining the number of turns in the primary winding required to obtain the impedance load that is best for optimal amplifier performance. Once the number of windings required is known, the pot core structure may be designed to take advantage of the size of the air gap, as discussed above. For embodiments of the present invention that are configured to act as an inductor only—and, therefore, have only one winding—the first step 60 is not applicable and, instead, one would start on the second step 62 . The second step 62 is to select the number of turns required in the secondary winding required to achieve electrical resonance between the secondary winding and the emitter. The third step 64 is to determine the optimal physical size of the pot core to contain the inductive device. The form factor of the entire parametric audio system will influence the size limitations of the device. The fourth step 66 is to select a size of the air gap 55 between the inner walls 54 a , 54 b required to decrease the overall physical size of the pot core while avoiding saturation of the inductive device during operation of the emitter, and to fine tune the inductive device.
[0044] In the typical pot core structure utilized in embodiments of U.S. Pat. No. 8,391,514, the determination of the fourth step 66 cannot be changed once the pot core structure has been manufactured. As a result, any distortion of the resultant signal caused by imperfections in the transducer circuit or unforeseen artifacts from miscalculation of the required number of turns cannot be addressed without re-manufacturing the structure. The presently disclosed technology improves upon the typical pot core structure, allowing for adjustments in the size of the air gap 55 in the pot core structure to compensate for these types of distortions. This adjustment allows for additional tuning of the audio system to achieve the optimal sound, with reduced distortion caused by the intense levels at which ultrasonic emitters are operated.
[0045] In various embodiments, the pot core inductive device includes an adjustment mechanism that allows adjustment of the air gap. FIG. 7 is a cross-sectional view of an example embodiment providing such adjustability. FIG. 8 is a diagram illustrating an exploded view of a pot core inductive device such as that shown in FIG. 7 . Like the typical pot core structure, the structure in this embodiment comprises two halves 70 , 71 that define a cavity 72 . Although ferrite is the most common material for pot core structures, use of other suitable materials is possible, as discussed above. Each half 70 , 71 comprises an outer wall 73 a , 74 a and an inner wall 73 b , 74 b . Disposed inside the cavity 72 is a coil support structure 75 . A coil structure, or inductor element, 76 is wound around the coil support structure 75 . This coil structure 76 can be configured as an inductor, transformer, or autotransformer. The type of coil structure 76 utilized will depend on the type of inductive device is optimal for the user, depending on desired performance, cost of construction, and level of quality of the resultant audio signal. The air gap 77 is formed in the void between the inner walls 73 b , 74 b of the two halves 70 , 71 .
[0046] In various embodiments, an adjustment mechanism 78 is provided to adjust the positions of halves 70 , 71 relative to one another. For example, the adjustment mechanism can be provided to allow adjustment or setting of the spacing between halves 70 , 71 . In other words, the adjustment mechanism can be used to adjust the volume of cavity 72 and the air gap 77 formed between inner walls 73 b , 74 b . In some embodiments, an additional air gap 79 may be formed between outer walls 73 a , 74 a , which may also be adjusted by the adjustment mechanism 78 . In other embodiments, the two halves 70 , 71 may be constructed such that a projection 85 from the outer wall of one half 73 a slots inside the outer wall of the other half 74 a , such that the cavity 72 is completely enclosed by the outer walls 73 a , 74 a . An example of this is illustrated in FIG. 9 .
[0047] Adjustment mechanism 78 can comprise any of a number of mechanisms to allow the halves 70 , 71 to be adjusted relative to one another. Preferably, the adjustment mechanism 78 also allows the positioning to be maintained over time, for example by using an elastomeric member 80 to maintain pressure against the adjustment mechanism as explained below.
[0048] In the example illustrated in FIG. 7 , adjustment mechanism 78 can include a male threaded member 81 configured to mate with a female threaded member 82 to adjust the spatial relation of halves 70 , 71 . Tightening the threaded members 81 , 82 would cause halves 70 , 71 to move closer together and close the air gap 77 , while loosening threaded members 81 , 82 would cause halves 70 , 71 to move farther apart thereby widening the air gap 77 .
[0049] In yet another embodiment, the adjustment mechanism 78 can comprise a threaded elongated member (e.g., a bolt or other like configuration) and the inner walls 73 b , 74 b can be provided with complementary threads so that female threaded member is not required. The threads presented by half 71 can be threaded in reverse as compared to the threads presented by half 70 such that, turning threaded member 81 causes halves 70 , 71 to move in opposite directions to or from one another. In another embodiment, only one half is threaded, and it can be moved along threaded member 81 relative to the other half.
[0050] In various embodiments, an adjustable means for securing the two halves may be used. The adjustable means may comprise a clamp attached externally to the two halves 70 , 71 , or similar structures. Means may also include locking channels disposed on the external sides of the two halves 70 , 71 that function to hold the halves 70 , 71 together, or similar structures. In some embodiments, the adjustment mechanism 78 and the adjustable means for securing the two halves 70 , 71 may be the same component.
[0051] The components of the adjustment mechanism can be made from a nonconductive, ferromagnetic material so as not to interfere with the electrical properties of the transductor. For example, the components of the adjustment mechanism can be made from various plastics, polyester, nylon, phenolic, and other nonconductive materials.
[0052] In embodiments where the spacing between halves 70 , 71 are fixed at a known predetermined dimension, coil support structure 75 can be dimensioned to have a tight fit within the cavity 72 . However, where the spatial relation between halves 70 , 71 is adjustable (such as, for example, via an adjustment mechanism 78 ) coil support structure 75 cannot be dimensioned for a tight fit within the cavity 72 throughout the range of adjustment. Accordingly, elastomeric member 80 can be included to provide a snug or tight fit for support structure 75 within cavity 72 . Elastomeric member 80 can be provided at a thickness so as to prevent support structure 75 from moving inside the cavity 72 .
[0053] In various embodiments, elastomeric member 80 can be disposed on a first inner surface 83 of cavity 72 and be configured to expand to apply pressure on coil support structure 75 against the opposite inner surface 84 of cavity 72 . In other embodiments, to elastomeric members 80 can be provided, one on each of the top and bottom inner surfaces. For example, as illustrated in FIG. 7 , elastomeric member 80 is placed in the bottom of cavity 72 , on inner surface 83 , and is configured to expand in height, H, to hold coil support structure 75 against the upper inner surface 84 of cavity 72 . Elastomeric member 80 is further configured to be compressible in the dimension H such that when the adjustment mechanism 78 is adjusted to bring halves 70 , 71 closer together, elastomeric member 80 compresses (decreases in height, H), allowing the height of the cavity 72 to be decreased. Conversely, when the adjustment mechanism 78 is adjusted to increase the separation between halves 70 , 71 , elastomeric member 80 can expand in height, H, maintaining a tight fit of coil support structure 75 within cavity 72 . In other embodiments, one or more elastomeric members 80 may be positioned in the top or bottom of cavity 72 . Still further embodiments could employ more than one elastomeric member 80 , with at least one disposed in each of the bottom and top of cavity 72 . The elastomeric member(s) 80 may be secured in place using a glue, epoxy, tape, or other nonconductive adhesives or fixation mechanisms. In other embodiments, the elastomeric member 80 could be designed as a removable element to allow repair or replacement of the elastomeric member 80 , or to allow a selectable number of members 80 to be utilized.
[0054] In further embodiments, elastomeric member 80 can be configured to provide sufficient expansive force to cause halves 70 , 71 to exert pressure against the adjustment mechanism 78 to maintain spatial relation there between as set by the adjustment mechanism 78 . In this respect, elastomeric member 80 can be configured to act like a spring applying an outward pressure against halves 70 , 71 against the adjustment mechanism 78 . Elastomeric member 80 can be ring- or donut-shaped to conform to the inner dimensions of half 70 (or 71 ) on the lower surface of cavity 72 . Elastomeric member 80 can be made using open- or closed-cell foams or other elastomeric materials having a spring-like property. Preferably, elastomeric member 80 is made of a nonconductive material so as to not interfere with the electrical characteristics of the inductive device.
[0055] As the above-described example embodiments illustrate, the pot core inductive device may include an adjustment mechanism, which can be configured to allow the air gap 77 to be increased or decreased to tune its inductance and achieve resonance with the emitter.
[0056] Employing the pot core inductive device in place of a typical pot core structure allows tuning of the amplifier and emitter system. This can be particularly useful, for example, in situations where other components of the audio system might not be tightly controlled. For example, the coil structure 76 within support structure 75 may come from the manufacturer or supplier to varying degrees of tolerance. In situations where the air gap 77 and the relation between halves 70 , 71 is fixed, variations in the coil structure 76 from one device to the next will result in variations in the inductance value from one device to the next. This, in turn, can impact the ability of these devices to create a resonant circuit with the emitter. Accordingly, providing an adjustable inductive device, with an adjustment mechanism 78 allows the inductance value to be brought to specification to account for variations in the coil structure 76 .
[0057] After selecting the pot core in accordance with the method illustrated in FIG. 6 , dynamic adjustments are possible by changing the air gap 77 in response to distortion in the audio signal. When the air gap 77 needs to be decreased, the adjustment mechanism 78 compresses the elastomeric material 80 to allow the two halves 70 , 71 to adjust the size of the air gap 77 . When the air gap 77 needs to be increased, the adjustment mechanism 78 is reversed and the elastomeric material 80 decompresses, allowing the two halves 70 , 71 to move apart and increase the size of the air gap 77 .
[0058] In various embodiments, the transductor half 71 and member 82 may be secured such that they do not need to be separately held in place when adjustment mechanism 78 is turned to adjust the spacing. For example, transductor half 71 can be glued, adhered, affixed with screws or other fasteners, or otherwise secured to the printed circuit board on which it is mounted so that it doesn't rotate in response to torque applied to adjustment mechanism 78 . Similarly, member 82 could likewise be secured to the printed circuit board. Alternatively, member 82 could be disposed in a complementary recess (not shown) in transductor half 71 to hold member 82 in place when torque is applied to member 78 .
[0059] FIG. 10 is a diagram illustrating a view of an assembled pot core inductor in accordance with one embodiment of the technology disclosed herein. In this diagram, the first and second halves of the ferromagnetic housing are shown as being disposed in an opposing configuration, and partially enclosing the wire windings of an inductive element wound around a support structure or bobbin. The adjustment mechanism, which in this embodiment is a nylon screw, is shown to the left of the assembled pot core structure and is not yet in place. FIG. 11 , illustrates a similar pot core structure in accordance with one embodiment, but with a nylon screw in place and being adjusted by the tip of a flat blade screwdriver.
[0060] While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not of limitation. Likewise, the various diagrams may depict an example configuration for the invention, which is done to aid in understanding the features and functionality that can be included in the invention. The invention is not restricted to the illustrated example configurations, but the desired features can be implemented using a variety of alternative configurations. Indeed, it will be apparent to one of skill in the art how alternative configurations can be implemented to implement the desired features of the present invention.
[0061] Although the invention is described above in terms of various exemplary embodiments and implementations, it should be understood that the various features, aspects and functionality described in one or more of the individual embodiments are not limited in their applicability to the particular embodiment with which they are described, but instead can be applied, alone or in various combinations, to one or more of the other embodiments of the invention, whether or not such embodiments are described and whether or not such features are presented as being a part of a described embodiment. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments.
[0062] Terms and phrases used in this document, and variations thereof, unless otherwise expressly stated, should be construed as open ended as opposed to limiting. As examples of the foregoing: adjectives such as “conventional” and “typical” and terms of similar meaning should not be construed as limiting the item described to a given time period or to an item available as of a given time, but instead should be read to encompass conventional, traditional, normal, or standard technologies that may be available or known now or at any time in the future. Likewise, where this document refers to technologies that would be apparent or known to one of ordinary skill in the art, such technologies encompass those apparent or known to the skilled artisan now or at any time in the future. | An apparatus and method for optimizing a parametric emitter system having a pot core inductive device coupled between an amplifier and emitter. The pot core inductive device allows for adjustments of the air gap formed between the two halves of the pot core structure to adjust its inductive value. This post-manufacture adjustability allows for corrections of differences caused by operations of other components in the audio system and to account for slight differences in the electrical circuit of different amplifier/emitter combinations. As efficiency of the system is dependent on the functional relationship between the amplifier, inductive device, and emitter, this allows for fine tuning of the signal to obtain high quality. | 7 |
This invention is related to International Application PCT/SE95/00226 filed Mar. 3, 1995, entitled "Motor Vehicle Gearbox".
BACKGROUND OF THE INVENTION
The present invention relates to a motor vehicle gearbox comprising a housing with an input shaft and two countershafts lying in a plane offset from the input shaft and having gears in engagement with gears on the input shaft, at least one gear of each pair of mutually engaging gears on said shafts being disengageable from its shaft, one of said disengageable gears being mounted on one countershaft and being disposed to transmit torque in the first gear speed to a final drive unit.
DESCRIPTION OF THE RELATED ART
A gearbox of the above described type is known, for example, by SE-A-8601247-3. It has five gear speeds forward and one reverse. The torque is transmitted in reverse from the input shaft via one countershaft to the other countershaft. In this way, the need for a separate shaft for the idler gear for reverse is eliminated. Instead, the first mentioned countershaft is used as a reverse gear shaft. This provides a particularly compact, simple and inexpensive design, which, with its axially small dimensions is particularly suited for use together with transverse engines.
SUMMARY OF THE INVENTION
The purpose of the present invention, starting from the above described gearbox, is to achieve a gearbox, which in a five-speed version can be made even shorter, and, in a six-speed version, will be as short as the known five-speed gearbox.
This is achieved according to the invention by virtue of the fact that the input shaft has at least five gears in engagement with gears on the countershafts for transferring torque to the final drive unit for forward drive with at least five different gear ratios, and that the disengageable gear for transmitting torque in the first gear speed engages an additional gear which is disengageably carried on a fourth shaft and is disposed to transmit reversing torque to the final drive unit.
In a six-speed embodiment of the gearbox according to the invention, the input shaft has six gears in engagement with gears on the countershafts.
In this embodiment, a disengageable gear for the sixth gear speed can assume the place taken by the reverse disengageable gear in a five-speed gearbox, and the reverse disengageable gear can instead be carried by an extra shaft. In comparison with the above mentioned known five-speed gearbox, one gear is eliminated in the drive train in reverse by virtue of the fact that the reverse disengageable gear on the fourth shaft engages directly the disengageable gear for the first gear speed and now, as in the known design, a gear solidly joined to the hub of the disengageable gear for the first gear speed. This also provides optimally small masses to be synchronized and a suitable gear lever shift pattern is obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in more detail below with reference to examples shown in the accompanying drawing, where
FIG. 1 shows a schematic longitudinal section through a five-speed gearbox according to the invention,
FIG. 2 is a longitudinal section through one embodiment of a six-speed gearbox according to the invention, and
FIG. 3 is a schematic end view of the gearbox shown in FIG. 2, and
FIG. 4 shows the shift lever shift pattern.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In a gearbox housing generally designated 1, which also forms the housing for the clutch, an input shaft 2, a first countershaft 3, a second countershaft 4, and a reverse gear shaft 5 are rotatably mounted. The input shaft 2 has five gears 6, 7, 8, 9, 10 (FIG. 1), of which the gear 6, 7, 8 and 9 are non-rotatably fixed, while the gear 10 is a disengageable gear, i.e. it is rotatably mounted on the shaft 2 and can be locked in a conventional manner by means of an engaging sleeve 12 with associated synchronizing means. The countershafts have gear 15, 16, 17, 18, 19 (FIG. 1), of which the gears 15, 16, 17 and 18 are disengageable, being locked to their shafts by means of engaging sleeves 21 or 22 with associated synchronizing means. The reverse gear shaft 5 has a disengageable gear 23, which can be locked to the shaft by means of an engaging sleeve 24 with associated synchronizing means.
On the intermediate shafts 3 and 4, a pair of gears 25 and 26 of equal size are non-rotatably fixed, and engage the crown-wheel 27 of a final drive unit, generally designated 28, in the form of a differential. A gear 29 is non-rotatably fixed to the reverse shaft 5. The gear 29 has a somewhat smaller diameter than the gears 25 and 26 and also engages the crown-wheel 27 of the final drive unit 28.
It is evident from FIGS. 1 and 2 which gears engage each other in the respective gear speeds; only the torque transmission in the first gear speed and in reverse will be described in detail here. With the gear 15 locked to the countershaft 4 by means of the engaging sleeve 22 and with the other disengageable gears disengaged, the highest gear ratio is obtained for forward drive, i.e. first gear. When shifting from first to reverse, the gear 17 is disengaged and the reversing gear 23 is instead engaged by means of the engaging sleeve 24, and the disengageable gear 17 for the first gear speed, which engages the reverse gear 23, serves as an idler gear to impart to the reverse shaft 5 a direction of rotation opposite to the rotational direction of the countershafts 3, 4 when driving forward.
By placing the reverse gear 23 on a fourth shaft 5, the five-speed gearbox can be made even shorter than the very shortest known five-speed gearbox.
A six-speed embodiment of the gearbox according to the invention, which is shown in FIG. 2 and which will be described below, can be achieved by building onto the five-speed gearbox. The length of the six-speed gearbox does not need to exceed the length of the shortest known five-speed gearbox. In FIG. 2, all of the components with counterparts in FIG. 1 have been given the same reference numerals as in FIG. 1. Differences in size between the disengageable gears and the gears for the gear speeds 1-5 and reverse, which result in differences in gear ratios between the two types, will not be regarded here.
The gearbox shown in FIG. 2 has a somewhat longer input shaft 2 and countershaft 4 than the gearbox in FIG. 1. A gear 11 is freely rotatably mounted on the extension of the input shaft 2. Said gear 11 is lockable onto the shaft by means of the same engaging sleeve 12 which locks the gear 10. Via the engaged gear 11 and a gear 20 fixed to an extension of the countershaft 4 as well as the gear 26, torque is transmitted in the third gear speed. In this example, the gear 10 transmits torque in the fourth gear speed. Torque in fifth and sixth gear speed is transmitted by the disengageable gears 16 and 15, respectively, on the countershaft 3.
The invention has been described above with reference to preferred embodiments for a transverse engine, but the principle of the invention can of course also be applied to a gearbox for a longitudinally mounted engine. An advantage of using the disengageable gear 17 for the first gear speed as an intermediate gear for reverse is that a high gear ratio is obtained. The same gears are also used for those gear speeds (first and reverse) on which the same requirements are placed as regards torque, gear ratio, noise level etc. | Motor vehicle gearbox, comprising an input shaft (2) and two countershafts (3, 4) having six pairs of interengaging gears (7-11, 15, 16, 17-20) for first to sixth gear. The disengageable gear (17) for the first gear speed engages a disengageable gear (23) on the fourth shaft (5) for reverse. | 8 |
SUMMARY OF THE INVENTION
The present invention relates to pressure welding and more particularly, to cold pressure welding.
It is already known to join a pair of metal members, such as sheets, plates etc. capable of being cold pressure welded by a lap joint by applying pressure to the superposed members substantially at right angles to the interface or weld area through the use of suitably shaped impression tools or dies. As a result of the applied pressure, metal is caused to flow outwardly from under the pressure applying die surfaces or weld area, thereby causing a merging or intimate union of the adjoining metals equilvalent to a solid phase welding bond at that area.
In a method of the above character, the metal flow varies within substantial limits at different points of the usual strip-like or rectangular weld area, being greater at the edges of the strip or longer sides of the rectangular weld area and being reduced towards the center on account of the greater impedance offered to the flow of the metal from the center towards the edges of the area. As a result, substantial welding pressure becomes necessary to insure a sufficient metal flow over the entire weld area conductive to efficient cold pressure welding, the pressure required being furthermore dependent upon the degree of hardness of ductility of the metals being welded. This, in turn, results in a substantial deformation or distortion of the parts of members being welded at and adjacent to the weld spot or area. Commonly, thickness reductions in the members to be joined, of 60 percent or more of each member are required to insure efficient welding. This thinning seriously weakens the weld area. Furthermore, practical limitations imposed by the necessity of applying sufficient pressure may result in unacceptably low bonding speeds.
Among the objects of the present invention is the provision of an improved method of and means for joining a pair of pressure weldable metal members by a lap joint which substantially overcomes the aforementioned and related difficulties and shortcomings, which will afford a more uniform metal flow and, in turn, a more efficient weld over the entire weld area, and which can be carried out easily and reliably while involving a minimum of rejects or defective welds.
With the aforementioned objects in view, the invention involves generally the provision of means for and an improved method of welding a pair of pressure weldable metal members which comprises essentially positioning a sacrificial metal interlay between the faying surfaces to be bonded and compressing the assembly until the interlay is properly spread over the faying surfaces. The interlay has a cross-section designed to produce a highly differential flow when subjected to external compressive loads. This differential flow causes shear movement between the interlay and the faying surfaces which effects the weld.
The invention is especially suitable for lapjoining by cold pressure welding the end portions of a pair of overlapping plates, strips, sheets or similar metal parts, arranged with their edges in register with one another and with the parts extending in the same direction.
Besides many other applications, the invention has special advantages in attaching a cover to a hollow cylindrical member such as welding a lid to a can by cold pressure welding. Thus, the edge of a can of aluminum or other cold weldable metal is flared outwardly to provide taper or cone. A lid having a surface which fits on the taper is placed on top of the can and the lid is welded to the taper by suitable cold pressure welding tools which make a ring weld. The surfaces to be welded together are previously cleaned to remove the oxide film and other surface contamination and to provide clean metal surfaces at the interface to be welded. If the projecting weld is undesirable, this can be dressed down by forcing the whole can top downwards through a die, the weld area then lying close up against the side of the can.
DESCRIPTION OF THE DRAWINGS
The invention will be better understood from the following detailed description taken in conjunction with the accompanying drawings, forming part of this specification and wherein:
FIG. 1 shows partly in section, a tool setup for welding a lid to a can in accordance with the invention;
FIG. 2 shows, partly in section, a tool setup for welding the side seam of a can; and
FIGS. 3a-3f show, in cross-sectional views, several interlay configurations.
Like reference characters identify like parts in the different views of the drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there is shown a can 1 and lid 2, both of pressure weldable metal. The can is of circular or any other section and has a bottom 1a attached by a double lap seam 1b or any other method. An outwardly directed frusto-conical taper 1d has been formed in the free extremity of the can wall 1c and a mating complementary taper 2a has been formed in the lid 2.
The can 1 is held in a die 3, wherein the die base 3a is adapted to grip the can bottom seam 1b to prevent radial displacement of the can 1, while the die sidewalls 3b provide support for the can taper 1d. The die 3, which is mounted on the platen of a hydraulic press or the like, may comprise a single piece or may be assembled from component pieces as an aid to tool fabrication.
A co-operating punch 4 is also mounted in the press such that it moves rectilinearly and coaxially with respect to the can 1. The punch is adapted to hold the lid 2 while supporting the lid taper 2a.
In operation, the faying surfaces 5 of the can taper 1d and the lid taper 2a are cleaned, using a rotary steel wire brush or the like, and a metal interlay 6 is placed therebetween to form a weld assembly. The punch 4 is then brought down under pressure, compressing the assembly and causing the interlay 6 to deform and spread over the faying surfaces 5, thereby welding the assembly in a solid phase bond.
Referring to FIG. 2, there is shown a sheet 7 of pressure weldable metal, bent to form a hollow cylinder. The sheet 7 is constrained between concentric circular male 8 and female 9 dies with the axial edges 10 overlapping; the overlap being exposed by an opening 11 in the female die 9. The dies 8 and 9 are mounted on the platen of a hydraulic press or the like.
A co-operating punch 4 is also mounted on the press such that it moves rectilinearily and radially with respect to the cylindrically formed sheet 7.
In operation, the faying surfaces 5 of the sheet axial edges 10 are cleaned, using a rotary steel wire brush or the like, and a metal interlay 6 is placed therebetween to form a weld assembly. The punch 4 is then brought down under pressure, compressing the assembly and, causing the interlay 6 to deform and spread over the faying surfaces 5 thereby welding the assembly in a solid phase bond.
The interlay 6 has a cross-section which results in a highly differential flow when subjected to external compressive loads; the ratio of the rate of deformation measured along one axis to the rate of deformation measured along a perpendicular axis preferably being in the range of 5:1 to 30:1, with the highest ratio being most preferably. Although the mechanism is not fully understood, it appears that the differential rates of flow between the interlay 6 and the two faying surfaces 5 produce an intense interfacial or shear flow. This shear flow serves to scrape off any oxide coating which may have formed on the faying surfaces 5 after the preweld cleaning (the presence of oxygen in the atmosphere causes these oxides to begin forming immediately after the cleaning) and which would tend to reduce the quality of a cold pressure weld. The flow further serves to cause intense localized facial heating. Further heating results from the pressure exerted on the weld assembly. The heat, the pressure and the intimate contact between the faying surfaces 5 and the interlay 6 all combine to produce the desired weld.
The desired differential in the shear flow rates is dependent upon the relative hardness of the interlay 6 and the base metal, the desired degree of thickness reduction of the base metal, and the surface condition of the interlay 6 and the faying surfaces 5.
The desired differential may vary during the course of effecting the weld. For example, it may be desirable to initially have a relatively low shear differential to scrape off any oxide coating on the interlay 6 or the faying surfaces 5, followed by a relatively high differential to effect the weld. Further, it may be desirable to have different shear flow differentials at the two faying surfaces 5 if the underlying base metals are of different hardness.
It is therefore, necessary to choose an interlay 6 configured to provide the desired time/location pattern of shear flow differential.
FIGS. 3a-3f illustrates some of the possible interlay 6 cross-sections, including round, oval, diamond with depressions at opposing corners, arrow-head and rectangular with asymetrically placed void. These sections, when compressed between two faying surfaces 5, will produce the desired highly differential flow, each, however, producing a different pattern of flow differential. Improperly designed cross-sections, such as simple rectangles, undergo thickness reduction without such differential flow. Instead, the interlay material merely extrudes in the unrestrained directions.
The pressure necessary to effect the weld is dependent upon the shear resistance of the interlay 6 and the faying surfaces 5. Preliminary results indicate that a pressure of about 150 percent of the surface stress of the interlay material is sufficient, provided that this pressure produces contact stresses at the points of contact between the interlay 6 and the faying surfaces 5 sufficient to cause some localized flowing of the base metal underlying the surfaces 5.
The interlay 6 is preferably softer than the base metal. When the interlay hardness is equal to or greater than that of the base metal, the interlay 6 does not spread over the faying surfaces 5, but, rather, cuts into the base metal. The proper hardness for the interlay 6 must be determined experimentally and largely depends upon the desired thickness reduction in the base metal, the minimum reduction occurring when the interlay 6 is very soft as compared to the base metal. Experimental results indicate that an optimum weld is achieved when the interlay thickness has been reduced by 65-99 percent. This may be accompanied by a thickness reduction in the base metal of about 5 percent. The interlay 6 may also be formed of a soft filler metal 6a with several fine wires 6b of a stronger, harder metal disposed therein (see FIG. 3f). The presence of these wires 6b increases the differential flow of the interlay 6 during the deformation process and elevates the shear resistance of the accomplished bond. Thus, the strength characteristics of the bond may be talored through proper orientation of the wires 6b.
Preliminary results indicate that this process permits cold pressure bonding at speeds of 10 feet per second.
While the invention has been described herein with specific reference to cold pressure welding, i.e. welding at room temperature or without the use of any appreciable amount of external heat, it will be understood that some heat may be applied to the members being welded provided, however, that welding is essentially effected as a result of the heat and pressure-induced plastic flow of the metal, to effect merging or intimate welding at the interfaces in the manner described. The additional heat may be supplied by either heating the pressure welding tools, or the members to be welded may be heated either before or during welding.
In the foregoing the invention has been described by reference to a few illustrative tools and methods. It is to be understood, however, that variations and modifications of both the described tools and method steps, as well as the substitution of equivalent tools and steps, may be made without departing from the broad scope and spirit of the invention as set forth in the appended claims. The specification and drawings are accordingly to be regarded in an illustrative rather than in a limiting sense. | An improved pressure welding technique permits high speed room temperature seam bonding of metal sheets. A metal interlay is placed between the faying surfaces to be bonded and the assembly is compressed until the interlay is properly spread over the faying surfaces. The interlay has a cross-section designed to produce a highly differential flow when subjected to external compressive loads. This differential flow causes shear movement between the interlay and the faying surfaces which effects the weld. Joining speeds in excess of 10 feet per second are possible, with a reduction in sheet thickness of about 5 percent. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to voltage regulator circuits, and more particularly, to an NMOS voltage reference generator employing a differential amplifier and suitable for application in integrated circuits.
2. Description of the Prior Art
The advantages offered by NMOS technology are well known; e.g., higher density, greater yield, etc. Thus smaller NMOS device geometries permit a greater number of devices to be produced per unit area or, stated another way, a single NMOS device will occupy less space. This characteristic is extremely important in the design and fabrication of complex digital integrated circuits; for example, single chip microprocessors.
Whereas digital circuitry is generally characterized by its "ON/OFF" or "ONE/ZERO" nature, most measurements in the real world are inherently analog; e.g., temperature, pressure, speed, voltage, etc. Therefore, it is often necessary that digital circuitry communicate or interface with analog circuitry. The required interfacing may be accomplished by providing analog components which are external to the chip; however, such arrangement generally requires more current, a larger power supply and commonly present more opportunities for design and manufacturing errors. To avoid these disadvantages, complex analog circuits are being manufactured integrally with the digital circuitry; e.g., on the integrated circuit chip itself, and due to the complex nature of the digital circuitry, the inclusion of the analog devices on the same chip requires that the same manufacturing process be employed.
It is often necessary to generate a voltage with which digital logic signals may be compared in order to determine their state. Since, for example, TTL logical zero levels are generally at or above threshold for a 5 volt NMOS circuit, it is necessary to create a reference voltage of about 1.5 volts to compare to the logic levels.
Circuits are known which are capable of generating a reference voltage which varies directly with the device threshold voltage. One such circuit is shown and described in U.S. Pat. No. 3,806,742 issued Apr. 23, 1974 and assigned to the assignee of the present invention.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved NMOS voltage reference generator.
It is a further object of the invention to provide an NMOS voltage reference generator which regulates to a fixed voltage.
It is a still further object of the invention to provide an NMOS voltage reference generator which presents a relatively low output impedance to a capacitive load.
According to a broad aspect of the invention there is provided an MOS voltage regulating circuit for generating a stable reference voltage between ground and a source potential, comprising: a voltage divider coupled to said source potential for dividing said source potential down to a first voltage; a differential amplifier comprised of field effect transistors, said differential amplifier having inverting and non-inverting inputs and a non-inverting output, said non-inverting input coupled to said voltage divider for receiving therefrom said first voltage, said stable reference voltage appearing at said inverting input; feedback means coupled to said non-inverting output and to said inverting input for raising the voltage at said inverting input to said reference voltage; and voltage pull-down means coupled to said feedback means and to said inverting input for reducing the voltage at said inverting input to said reference voltage.
The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a first embodiment of the inventive voltage reference generator; and
FIG. 2 is a schematic diagram of a second embodiment of the inventive reference voltage generator.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there is shown a reference voltage generating circuit in accordance with the present invention, including a resistive voltage divider, a differential amplifier and an output feedback stage. The resistive divider comprises resistors 2 and 4 coupled in series between ground and a source of supply voltage V D and having an output node 6. With V D equal to 5 volts, a voltage at output node 6 of 1.5 volts may be achieved by properly scaling resistors 2 and 4.
A differential amplifier comprises MOSFETs 8, 10, 14, 16 and 22 having non-inverting and inverting inputs coupled to nodes 6 and 24 respectively, and having inverting and non-inverting outputs at nodes 9 and 20 respectively. MOSFETs 8 and 16 are of the depletion type, and MOSFETs 10, 22 and 14 are of the enhancement type. It should be noted that in the art, the acronym MOSFET is widely used to include within the scope of its meaning, all insulated gate field effect transistors, and this is the intended meaning of the term as used herein in the description of this invention. It should be recognized by those skilled in the art that a MOSFET may be of the P-channel type or N-channel type. While it is assumed herein that N-channel MOSFETs are used, it should be understood that P-channel MOSFETs may also be used. It is also well-known that a MOSFET is a bilateral device having two main electrodes which may interchangeably function as source or drain electrodes depending on which is at the more positive voltage. The convention adopted for the description herein is that the main electrodes will each be identified as either a source or drain although it is understood that during circuit operation any electrode identified as a source may function as a drain part of the time.
MOSFETs 8 and 10 are coupled with their source drain paths in series between the source of supply voltage V D and node 12. The gate of depletion MOSFET 8 is coupled to its source (the inverting output) and the gate of MOSFET 10 is coupled to node 6 (the non-inverting input). MOSFETs 16 and 22 are likewise coupled with their source drain paths in series between the source of supply voltage V D and node 12. The gate of MOSFET 16 is coupled to its source (the non-inverting output), and the gate of MOSFET 22 is coupled to node 24 (the inverting input) from which the reference voltage V Ref is taken. MOSFET 28 is of the enhancement type and functions as a source follower with its gate coupled to the gate of device 16 and to node 20. Its source is coupled to node 24, and its drain is coupled to the supply voltage V D . MOSFET 26 is also of the enhancement type and is coupled as a diode with its gate tied to its drain. MOSFET 26 acts as a DC load to ground to assure that device 28 remains in the active region. MOSFET 14 has its source-drain path coupled between ground and node 12, and has its gate electrode coupled to the source of supply V D .
The circuit of FIG. 1 operates as follows. Resistors 2 and 4 are scaled to produce a voltage at node 6 of approximately 3/10ths V D or 1.5 volts. Thus, to balance of differential amplifier, a voltage of approximately 1.5 volts appears at the gate of device 22 which is the inverting input of the differential amplifier. If the voltage at node 24 should fall below the 1.5 volt level, MOSFET 22 will begin to turn off raising the voltage at node 20 (the non-inverting output). This in turn causes device MOSFET 28 to turn on harder thus pulling node 24 back up to the 1.5 volt level. If, on the other hand, the voltage at node 24 should rise above 1.5 volts, thus increasing the gate drive to MOSFET 22, MOSFET 22 will turn on harder reducing the voltage at node 20 which tends to shut down MOSFET 28. The current through diode connected MOSFET 26 will increase pulling the voltage at node 24 back down.
MOSFET 14 having its gate coupled to the supply voltage V D acts as a current source and also assists in compensating for power supply variation. Since the current through device 14 is essentially linear with respect to V D , raising V D will increase the current through device 14 and correspondingly through devices 8 and 16. The result is an increased voltage drop across device 16 which lowers the voltages at nodes 18 and 24 with respect to V D . This will minimize the effect of the power supply variation at node 24.
The circuit shown as FIG. 1 can be further improved by eliminating device 8 entirely and tying the drain of MOSFET 10 directly to the supply voltage V D . In this manner, MOSFET 10 is always in saturation and is not subject to current variation as a result of channel length modulation.
The circuit shown in FIG. 2 is a modified version of the circuit shown in FIG. 1 and produces a faster return to the reference voltage after a positive excursion. In this circuit, enhancement device 26 is not diode connected but is cross-connected with an additional enhancement device 30. That is, the drain of MOSFET 26 is coupled to the gate of MOSFET 30, and the gate of MOSFET 30 is coupled to the drain of MOSFET 26. The sources of both MOSFETs 26 and 30 are coupled to ground. An additional device 32 has a drain coupled to the supply voltage V D , a gate coupled to node 9, and a source coupled to the drain of device 30 and to the gate of device 26. All other elements are the same as that shown in FIG. 1 and are denoted with like reference numerals.
During a positive excursion of the reference voltage at node 24, device 22 is turned on harder reducing the voltage of node 20. The voltage at node 9 increases turning device 32 on harder. This increases the gate voltage of device 26 causing it to turn on harder, thus pulling the reference voltage back down to 1.5 volts.
In summary, the present invention provides an MOS reference voltage generator circuit which provides a low impedance output and offers some compensation for power supply variation. While the invention has been shown in connection with specific embodiments thereof, it will be apparent to those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention as defined by the appended claims. | An NMOS voltage regulator circuit generates a reference voltage for comparison with, for example, TTL logic levels. A resistive voltage divider coupled to a 5 volt source produces a voltage of, for example, 1.5 volts which is applied to the non-inverting input of a differential amplifier. The reference voltage appears at the inverting input of the differential amplifier. Field effect transistor means are provided to raise or lower the voltage at the inverting input depending on whether a negative or positive excursion has taken place. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to the synthesis of aryl substituted silicone fluids by the hydrosilylation of an aryl substituted acetylene, such as phenylacetylene or diphenylacetylene with a hydride-functionalized silicone fluid.
Silicones fluids having a high refractive index, such as about 1.50, are of interest to the hair care products industry. For example, in addition to providing good feel, wet combing, and low static, silicones having a high refractive index can offer a maximum amount of sheen to hair.
It is generally known to those skilled in the silicone art, that a convenient way to increase the refractive index of a polydiorganosiloxane fluid consisting essentially of chemically combined dialkylsiloxy units is to introduce into the polydiorganosiloxane backbone, a significant number of siloxy units having aryl radicals attached to silicon by carbon-silicon bonds.
Various techniques are available for introducing arylsiloxy units into organopolysiloxanes. One method is based on the use of a convenient source of arylsiloxy such as a polydiorganosiloxane having siloxy units with phenyl radicals attached to silicon by carbon-silicon linkages. However, experience has shown that diphenylsiloxane copolymers have a tendency to crystallize at high levels of diphenylsiloxane. The incorporation of aryl radicals, such as a styrl substituent, into a polydiorganosiloxane using a hydrosilylation reaction is also another alternative for increasing arylsilicon substitution.
As reported by L. N. Lewis et al. in Organometallics, 1991, 10,3750, arylacetylenes, such as phenylacetylene, can undergo facile hydrosilylation with monomeric silylhydrides. Diphenylacetylene has been shown by M. Tanaka et al. Bull. Soc. Fr. 1992, 129, 667.b, to undergo dehydrogenative double silylation with a bis(hydrosilane) to give a cyclic unsaturated compounds as the major product.
Additional procedures are constantly being evaluated for providing silicone fluids having high indices of refraction.
SUMMARY OF THE INVENTION
The present invention is based on the discovery that aryl substituted silicone fluids having high indices of refraction and a viscosity in the range of 100 to 40,000 centipoise at 25° C., and preferably 1 00 to 20,000 at 25° C., can be made by the hydrosilylation of arylacetylenes. Arylacetylenes having the formula,
R-C C-R.sup.1, (1)
where R is a C.sub.(6-13) monovalent aryl radical, and R 1 is hydrogen or an R radical, can be hydrosilylated with a member selected from the group consisting of,
(a) a linear hydridosiloxane which consists essentially of at least one terminal unit of the formula,
R.sup.2 (R.sup.3).sub.2 SiO.sub.1/2, (2)
where R 2 is a monovalent radical selected from the group of hydrogen and a C.sub.(1-13) monovalent organic radical, and R 3 is a C.sub.(1-13) monovalent organic radical, and from 1 to 100 chemically combined disiloxy units selected from the group consisting of organohydridosiloxy units,
H(R.sup.3) SiO, (3)
and, a mixture of such organohydridosiloxy, and diorganosiloxy units,
(R.sup.3).sub.2 SiO, (4)
and,
(b) a (3-8) cyclic hydridosiloxane consisting essentially of a member selected from the group consisting of the organohydridosiloxy units of (a) and a mixture of such organohydridosiloxy units and the diorganosiloxy units of (a).
In a further aspect of the present invention, it also has been found that the aryl substituted silicone fluids include aryl substituted silicone fluids having a conjugated aryl group either in the form of a styryl or styrenyl group, in instances where R 1 in formula 1 is hydrogen, and a diaryl group, such as a stilbene group, where R 1 in formula 1 is R. Surprisingly, the presence of such conjugated groups, has been found to enhance the refractive index of such silicone fluids.
STATEMENT OF THE INVENTION
There is provided by the present invention, an aryl substituted silicone fluid having a viscosity in the range of about 100 to about 40,000 centipoise at 25° C., and a refractive index of at least 1.5, comprising chemically combined diorganosiloxy units of the formula,
QR.sup.3 SiO, (5)
where Q is a conjugated monovalent aryl radical selected from the group consisting of alkenyl substituted C.sub.(6-13) monoaryl radicals, and alkenyl substituted diC.sub.(6-13) aryl radicals, and R 3 is as previously defined.
In a further aspect of the present invention, there is provided a method for making an aryl substituted silicone fluid having a refractive index of at least 1.5, comprising effecting the hydrosilylation of an arylacetylene of formula (1), with a linear hydridosiloxane having from 1 to about 80 chemically combined disiloxy units selected from the group consisting of formulas 2 and 3, or 2 and a mixture of 3 and 4, or a (3-8) cyclic hydridosiloxane consisting essentially of chemically combined units of formula 3, or a mixture of 3 and 4.
DETAILED DESCRIPTION OF THE INVENTION
Radicals which are included within R of formula 1, are phenyl, tolyl, xylyl, and naphthyl, and preferably phenyl; haloaryl, such as chlorophenyl, alkoxy aryl such as methoxy phenyl, and nitro aryl are also included. In addition to hydrogen, radicals included within R 2 , and organo radicals of R 3 , are for example, C.sub.(1-8) alkyl radicals, such as methyl, ethyl, propyl, butyl and pentyl; haloalkyl for example trifluoropropyl; alkenyl radicals such as vinyl, and propenyl; cycloalkenyl, for example cyclohexenyl; C.sub.(6-13) aryl radicals such as phenyl, tolyl, xylyl, and naphthyl, and preferably phenyl, methoxyphenyl; haloaryl, such as chlorophenyl.
Preferably, the arylacetylenes of formula (1) are for example, phenylacetylene, diphenylacetylene, and the corresponding chloro, nitro, and methoxy derivatives. Additional arylacetylenes, such as arylacetylene compounds having substituents shown for R, are also included.
The linear hydridosiloxane having terminal units of formula (2), which consist essentially of disiloxy units shown by formulas (3) and (4), are preferably polydisiloxanes having terminal dimethylhydrogensiloxy units or trimethylsiloxy units, which linear hydridosiloxane can consists essentially of methylhydrogensiloxy units, or a mixture of methylhydrogensiloxy units and dimethylsiloxy units. These linear hydridosiloxanes preferably have from about 1 to about 80 disiloxy units and 0.2% to 1.6% of chemically combined hydrogen. The cyclic polydimethylsiloxanes are preferably cyclic trimer, tetramer and pentamer.
Experience has shown that in instances where diarylacetylene is used in the preparation of the aryl substituted silicone fluids of the present, solidification of the hydrosilylation product will likely occur, unless a C.sub.(2-8) olefinic comonomer reactant, such as hexene, is concurrently used during the hydrosilylation step.
Although the aryl substituted silicone fluids can have a viscosity in the range of about 100 to about 20,000 centipoise at 25° C., depending on such factors as the nature of the substituents attached to silicon in the polydiorganosiloxane backbone, the linear length or cyclic size of the silicon hydride fluid used in the preparation of the fluid, the viscosities of the respective fluids can vary widely. For example, in instances where the fluid backbone is linear and substituted with hexane groups and phenylacetylene, or diphenylacetylene groups, a viscosity of about 100 to about 32,000 centipoise at 25° C. is not unusual.
Depending upon the nature of the reactants, the aryl substituted silicone fluids can be made by the hydrosilylation of arylacetylene with the hydridosiloxane fluid, or by the hydrosilylation of hydrolyzable silanes followed by cohydrolysis with appropriate diorganosilanes, such as dimethyldichlorosilane. In instances where hydrosilylation is used, platinum group metal catalyst, such as chloroplatinic acid, finely divided platinum metal, and platinum catalyst shown by Ashby, U.S. Pat. No. 3,159,601 and Karstedt, U.S. Pat. No. 3,775,452. An effective amount of platinum catalyst is 5 ppm to 200 ppm of Pt based on the weight of the hydrosilylation mixture. A temperature in the range of 25° C. to 150° C. can be used. An inert organic solvent is optional. Suitable inert solvents are cyclohexane, 2-propanol, toluene, hexane and heptane.
In order that those skilled in the art will be better able to practice the present invention, the following examples are given by way of illustration and not by way of limitation. All parts are by weight unless otherwise indicated.
EXAMPLE 1
A mixture of 85.45g (0.838 mol) of phenylacetylene, 12.36 g (0.147 mol) of 1-hexene, 70.74 g (0.93 mol Si-H) of a poly(methylhydrido)siloxane fluid having terminal trimethylsiloxy units and having an average of about 10 methyhydridosiloxy units, and sufficient platinum catalyst shown by Karstedt, U.S. Pat. No. 3,775,452, to provide 36 ppm of Pt catalyst based on acetylene, was heated with stirring to 60° C. for one hour and 75° C. for two hours. After stripping excess hexene, there was obtained 162 g of an orange, clear fluid. It had a viscosity of 5915 cSt, and a R.I. of 1.5465; GPC analysis showed a Mw of 3190 and Mn of 1680. Based on method of preparation, the product was a phenyl silicone fluid and useful as a hair product component.
EXAMPLE 2
A procedure similar to example 1 was performed, except that a poly(methylhydrido)siloxane fluid was used having 3.79 mol of Si-H and an average of about 80 methyhydridosiloxy units, 450 g of phenylacetylene, 280 g of a solvent in the form of a mixture of C 12 branched alkanes. The mixture was heated at 8 hours at 75° C., and at 80° C. for 2 additional hours using a total of 99 ppm of Pt catalyst. There was obtained 60 g of an orange, slightly hazy fluid having a viscosity of 32,000 centipoise and an R.I. of 1.5720.
EXAMPLE 3
There was added over a period of one hour, 4.76 g (79.3 mol of Si-H) of tetramethylcyclotetrasiloxane to a stirred mixture heated to 60° C. of 8.39 g (82.3 mol) of phenyl acetylene, 6 g of cyclohexane, and 40 ppm of Pt based on acetylene. The mixture was then heated for one hour to 75° C. The mixture was then stripped of volatiles at 50° C. under reduced pressure. There was obtained 12.0 g of an orange, slightly hazy fluid having a viscosity of 1000 cSt and an R.I. of 1.5745. The fluid was a phenyl silicone useful as a component in a hair preparation.
EXAMPLE 4
A procedure similar to example 2 was carried out, except that there was added over a period of one hour, 231g (3.79 tool Sill) of a linear hydridosiloxane having an average of about 15 methylhydridosiloxy units and terminal hydridodimethylsiloxy units to a mixture at 55° C. of 450 g of phenylacetylene, 280 g of a mixture of C 12 branched alkanes as a solvent, and 250 ppm of Pt. The reaction mixture was heated at 75° C. for 15 hours and then heated an additional five hours at 80° C. in the presence of an additional 39 ppm of Pt. Vacuum distillation at 75° C. provided an orange, slightly hazy fluid having a viscosity of 6000 centipoise at 25° C. and an R.I. of 1.5745.
EXAMPLE 5
There was added 3.42 g (19 mmol) of diphenyl acetylene dissolved in 2-3 g of toluene to a mixture stirring for one hour at 80° C. consisting of 0.41 g (4.9 mmol) of 1-hexene, 2.42 g (24.0 meq Si-H) of a poly(methylhydrido)siloxane fluid having terminal trimethylsiloxy units and an average of about 4 methyhydridosiloxy units and 70 ppm Pt based on acetylene. After an additional one hour at 80° C., the mixture was stripped of volatiles at 100° C. to provide 5.1g of a pale yellow fluid having an R.I. of 1.5615.
EXAMPLE 6
A procedure substantially similar to example 5 was carried out, except that 1.62 g (24.2 meq Si-H) of tetramethyldisiloxane was substituted as the poly(methylhydrido)siloxane fluid and a 50:50 mole of diphenylacetylene to hexene. There was obtained, 3.94 g of a pale yellow fluid having an R.I. of 1.5275.
EXAMPLE 7
There was added over a period of one-half hour, 16.1 g (0.14 mol) of dichloromethylsilane to a stirring refluxing mixture of 25.0 g (0.14 mol) of diphenyl acetylene, 200 ml of methane, and sufficient Pt catalyst to provide 220 ppm of Pt based on acetylene. After 17 hour, GC analysis showed complete conversion to product. The mixture was stripped of hexane. The residue was distilled at 121 ° C./0.2 torr to provide 36 g (88% yield) of a colorless liquid. Based on method of preparation, the product was 1-phenyl-1-(dichloromethylsilyl)-2-phenyl ethylene.
A mixture of 25 g (0.085 mol) of 1-phenyl-1-(dichloromethylsilyl)-2-phenyl ethylene and 11.0 g (0.085 mol) of dichlorodimethylsilane was added slowly to a solution cooled to °C. of 125 ml of water and 20 g of KOH. There was obtained a white solid. The solid was extracted into dichloromethane. The dichloromethane solution was washed with 10% HCl and water and dried with MgSO 4 . The filtered organic layer provided 23.5 g of an aryl silicone fluid in the form of a viscous oil having an R.I. of 1.581. | A method is provided for making silicone fluids having a high refractive index by effecting a hydrosilylation reaction between an arylacetylene such as phenylacetylene and a silicon hydride substrate, such as a cyclic or linear hyridosiloxane in the presence of a platinum catalyst. | 2 |
RELATED APPLICATIONS
[0001] This applications claims priority from and incorporates by reference German patent application 10 2014 102 617.9 filed on Feb. 27, 2014.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a hydraulic valve for a cam phaser.
[0003] Hydraulic valves for cam phasers in general are well known. The hydraulic valve includes a flowable valve piston which is received axially moveable in a valve housing of the hydraulic valve. The valve housing is configured with flowable channels so that a hydraulic fluid can flow through these channels and can flow in and out of the valve housing on different flow paths through a channel system configured in the valve piston. Typically the valve housing includes a flowable first operating connection, a flowable second operating connection and a flowable supply connection. The first operating connection and the second operating connection are connected with the cam phaser and the hydraulic fluid is feedable into the hydraulic valve and also out of the hydraulic valve through these connections. In order to supply the hydraulic valve with the hydraulic fluid fed by a feed device the valve housing includes the supply connection. In order to use cam shaft switching moments check valves are positioned in the flow paths of the operating connections, either in the valve housing or in the valve piston. Furthermore a check valve is configured in a flow path of the supply connection so that the hydraulic fluid can flow through the supply connection into the valve housing or into the valve piston, however, so that an exit of the hydraulic fluid through the flow path of the supply connection is blocked. Due to the check valves the hydraulic fluid in the hydraulic valve is controllable as a function of pressure.
[0004] Thus, for example the publication document DE 10 2009 043 154 A1 discloses a hydraulic valve with a check valve configured as a ball check valve which is arranged in the flow path of the supply connection between the supply connection and the feed device.
[0005] From the publication DE 10 2008 006 179 A1 a hydraulic valve is known which includes a support sleeve for the valve piston which is axially moveable in the valve housing. Openings are provided in the support sleeve which are configured for flowing through the hydraulic valve in combination with the flowable channels in the valve housing. A woven filter material is provided between the valve housing and the support sleeve. Typically the hydraulic fluid is filtered in a supply channel to which the supply connection is associated, wherein the filtering is performed with a respective separation device, for example an oil separator sleeve. The woven filter material is provided for filtering the hydraulic fluid for example for retaining chips which can be produced when mounting the separation device. Chips that reach the valve housing can on the one hand side impede movability of the valve piston, on the other hand side they can block the channels and the channel system so that the hydraulic valve cannot perform its function any more. A check valve configured as a ball check valve is arranged in the section of the supply connection in order to prevent a back flow of the hydraulic fluid from the valve piston into the supply connection.
[0006] The publication document DE 10 2008 036 182 A1 discloses a hydraulic valve which is provided for simplifying a supply to cam bearings. In order to block a hydraulic fluid outflow from the hydraulic valve into the supply channel of the cam bearings a check valve configured as a ball check valve is arranged at a face of the hydraulic, which face is oriented towards the cam shaft.
[0007] An improvement of responsiveness shall be achieved by the hydraulic valve with two spring loaded check valves that can be derived from publication document DE 10 2008 036 876 A1. The two check valves are provided for blocking an outflow of the hydraulic fluid in a direction towards the feed device. Using the two check valves contrary to just using one check valve shall safely prevent a back flow of the hydraulic fluid. Furthermore the two check valves facilitate adapting an effective pass through cross section to the respective conditions for quickly loading the hydraulic valve and thus to provide improved responsiveness of the hydraulic valve. This means for example operating an internal combustion engine including the cam shaft at high speeds feeds a correspondingly large hydraulic fluid flow which requires a large effective pass through cross section for quickly loading the hydraulic valve. By comparison a small effective pass through cross section is required for achieving a quick loading at low speeds.
[0008] A hydraulic valve that is configured as a check valve but not as a ball check valve can be derived from the publication document WO 2009/089 960 A1. In order to obtain quick response of the hydraulic valve and an increase of the adjustment speed of the cam phaser a closure element of the check valve in a flow cross section of the supply connection is disclosed which closure element is configured disc shaped and arranged in an inflow channel of the hydraulic valve for the supply connection. The disc for opening and closing the inflow channel includes a closure element which is supported at the disc in a spring elastic manner. A disc is disclosed with a ring that is configured with spring elements, wherein the closure element is arranged within the ring. The closure element is integrally connected with the ring in one piece. The spring elements are illustrated with groove shaped channels completely penetrating the disc along its thickness so that a spring element that is respectively configured between two channels is moveable in a spring elastic manner along a longitudinal axis of the disc. The idea is to achieve quicker closing or opening of the check valve due to a greater effective inflow surface and lower mass inertia compared to a ball check valve. An inflow of hydraulic fluid from the supply connection into the valve piston is provided through the spiral or wave arc shaped channels which are simultaneously used for providing the spring elements and through a lift off of the closure element from the inflow channel, however so that the disc is fixated at its outer circumference.
BRIEF SUMMARY OF THE INVENTION
[0009] Thus, it is an object of the present invention to provide a hydraulic valve for a cam phaser which assures safe closure and sufficient supply for the hydraulic valve at low camshaft speeds and also at high camshaft speeds and which has a simple and cost effective configuration.
[0010] The object is achieved according to the invention by a hydraulic valve for a cam phaser including a valve housing with a longitudinal axis and a valve piston that is axially moveable along the longitudinal axis, wherein the valve piston opens and closes a first operating connection of the valve housing and a second operating connection of the valve housing, wherein the first operating connection and the second operating connection are axially offset from one another; and a supply connection of the valve housing which is used for supplying the hydraulic valve with a hydraulic fluid fed by a feed device, wherein the hydraulic valve is configured to be flowed through by the hydraulic fluid on different paths controlled by a flow permeable channel system of the valve piston, and wherein a check valve opening and closing an inflow channel is arranged in the hydraulic valve in the inflow channel of the valve housing which inflow channel is associated with the supply connection, wherein the check valve includes a disc shaped flow permeable first closure element with a first pass through opening and a spring element, characterized in that the check valve includes a flow permeable second closure element with a second pass through opening, wherein the first pass through opening is arranged opposite to a non flow permeable second outer section of the second closure element, and wherein the second pass through opening is arranged opposite to a non flow permeable first inner section of the first closure element, so that a relative movement between the first closure element and the second closure element causes an opening or closing of the check valve.
[0011] Advantageously embodiments with useful and non trivial variations of the invention are provided in the dependent claims.
[0012] The hydraulic valve according to the invention for a cam phaser with a valve housing and a valve piston that is moveable along a longitudinal axis of the valve housing includes a check valve which is received in a flow channel of the valve housing upstream of the valve piston and downstream of a supply connection of the valve housing. The supply connection is used for supplying hydraulic fluid to the hydraulic valve. The check valve is arranged in the supply channel so that the supply channel is openable or closeable by the check valve so that the hydraulic fluid cannot flow back from the inflow channel towards the supply connection.
[0013] The check valve includes a flowable disc shaped first closure element including at least a first pass through opening and a flowable second closure element including at least a second pass through opening. Since both closure elements include a pass through opening it is required for achieving a sealing effect or closing the check valve that the closure elements are arranged so that the first pass through opening is arranged opposite to a non flowable first section of the second closure element and the second pass through opening is arranged opposite to a non flowable second section of the first closure element so that opening or closing the check valve is performed based on a movement of the two closure elements relative to each other. The two accordingly configured closure elements provide a secure closure of the check valve in a simple manner since the pass through openings of the two closure elements can be closed by the respective opposite closure element as a result of a relative movement. Put differently this means that in case the two closure elements move towards each other a sealing contact between the two closure elements can be established, wherein the pass through openings are closed due to their positioning.
[0014] Opening the check valve can be performed rather quickly since the pass through openings are released already for a small movement of the two closure elements relative to one another where they move away from each other so that hydraulic fluid can flow from the first pass through opening between the first closure element and the second closure element already for a small displacement of the two closure elements from each other so that the hydraulic fluid flows through the second closure element into the valve piston.
[0015] In a second embodiment of the hydraulic valve according to the invention the first pass through opening is arranged in an outer section of the first closure element and the second pass through opening is configured in a center of the closure element.
[0016] Compared to the check valves known in the art the advantage is that on the one hand side an assured sealing effect is obtainable due to the pass through openings that are arranged relative to another accordingly and on the other hand side it is possible to release a sufficiently large flow cross section as quickly as possible so that a quick response of the hydraulic valve is provided.
[0017] Advantageously the first closure element is configured independently from the second closure element so that an uncomplicated and thus cost effective production can be implemented.
[0018] In another embodiment of the hydraulic valve according to the invention the first pass through opening is configured in a first outer section of the first closure element and the second pass through opening is configured in a second inner section of the second closure element. This has the advantage that the hydraulic fluid when flowing into the valve piston from the second pass through opening does not go through any or almost no change in flow direction so that flow loses are largely prevented so that also this configuration facilitates a quick response of the hydraulic valve.
[0019] It is another advantage of the solution according to the invention that disc shaped closure elements with the accordingly arranged pass through openings can be produced in a cost effective manner. Thus, the closure elements can be made for example from a sheet material which can be worked in a simple manner. The pass through openings can be introduced into the disc through a stamping method simultaneously with fabricating the disc.
[0020] Another advantage of the disc shaped closure elements is little wear of components that contact each other during operations when closing the check valve due to a greater contact or impact surface compared to the known check valves.
[0021] An axial movement of one of the two closure elements, advantageously of the second closure element arranged proximal to the valve piston is easily supported by a spring element which is advantageously configured as a coil spring. Thus, the spring element only has a supporting effect in that it causes on the one hand side a quicker closure and on the other hand side a safe closure since already a pressing force impacting the second closure element due to pressure spikes at the valve piston achieves an axial movement of the second closure element in a direction of the first closure element. When the second closure element reaches the first closure element the spring element additionally imparts a pressure force for safe closure.
[0022] Overall the hydraulic valve according to the invention is characterized by a simple configuration of its check element so that simple and quick assembly can be provided. Axially securing the spring element is provided by a second shoulder configured in the hollow cylinder and axially securing the first closure element is obtained in a simple manner with a first shoulder provided in the inflow channel and a retaining ring received in an inflow channel in a ring groove. The shoulders are thus produced e.g. through internal turning. This means the check valve of the hydraulic valve according to the invention is characterized by simple production of the closure elements and simple assembly, and the hydraulic valve is influenced very little by its installation position.
[0023] The first pass through opening is configured groove shaped over a circular circumference and the second pass through opening is configured circular so that a large effective flow cross section of the check valve is achievable so that a quick response of the hydraulic valve can be provided even for high engine speeds since a sufficient amount of the hydraulic fluid can flow in a respectively required short time period through the pass through openings into the supply channel of the valve piston.
[0024] Due to the configuration of the check valve sensitivity with respect to contamination is greatly reduced. Thus, the check valve can be adjusted in the same simple manner that is used for mounting. Materials optimization facilitates further improvement of the reaction time and leak tightness. Overall the check valve is characterized by a low loading of the disc shaped closure elements and overall of the components that are configured adjacent to the closure elements since only the second closure element has to be moved in addition to the spring element.
[0025] Secure closure of the check element prevents an opposite pressure on a filter that is provided upstream of the check element in the flow path of the supply connection, in particular a sieve, so that a loading of the sieve is reduced and its service life is extended.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Further advantages, features and details of the invention can be derived from a subsequent description of advantageous embodiments with the reference to drawing figures. The features and feature combinations recited in the preceding description and the features individually recited in the subsequent figure description or illustrated in the figures are not only useable in the respectively provided combination but are also useable by themselves or in other combinations without extending beyond the scope of the invention. Identical or functionally equivalent elements have identical reference numerals. For reasons of clarity it is possible that the elements are not provided with respective reference numerals in all figures, while maintain their association, wherein:
[0027] FIG. 1 illustrates a longitudinal sectional view of a hydraulic valve for a cam phaser with a check valve configured as a ball check valve that is known in the art;
[0028] FIG. 2 illustrates a longitudinal sectional view of a hydraulic valve according to the invention;
[0029] FIG. 3 illustrates a longitudinal sectional view of the hydraulic valve according to the invention according to FIG. 2 ;
[0030] FIG. 4 illustrates a top view and a longitudinal sectional view of a first closure element of a check valve of the hydraulic valve according to FIG. 2 ;
[0031] FIG. 5 illustrates a top view and a longitudinal sectional view of the check valve of the hydraulic valve according to FIG. 2 ;
[0032] FIG. 6 illustrates a view in principle of the first closure element and the second closure element according to FIGS. 4 and 5 in a longitudinal sectional view in a first relative position;
[0033] FIG. 7 illustrates a view in principle of the first closure element and the second closure element in a longitudinal sectional view in a second embodiment in a second relative position; and
[0034] FIG. 8 illustrates a view in principle of the first closure element and the second closure element in a third embodiment in the second relative position.
DETAILED DESCRIPTION OF THE INVENTION
[0035] A cam phaser that is not illustrated in more detail facilitates changing opening and closing times of gas control valves of an internal combustion engine which is not illustrated in more detail. Thus, the cam phaser according to the invention continuously adjusts a relative angular position of a cam shaft of the internal combustion engine relative to a crank shaft of the internal combustion engine wherein the cam shaft and the crank shaft are not illustrated in more detail and wherein the cam shaft is not rotated relative to the crank shaft.
[0036] Rotating the cam shaft moves the opening and closing times of the gas control valves so that the internal combustion engine produces optimum power at a respective speed. Controlling the cam phaser is typically provided by an electronic control unit which controls an inflow and an outflow of hydraulic fluid in pressure chambers provided in the cam phaser based on parameters of the internal combustion engine. A hydraulic valve 1 controlled by electrical signals from a control unit is used for controlling inflow and outflow of the hydraulic fluid, wherein the hydraulic valve according to the prior art as illustrated in FIG. 1 is configured with a check valve configured as a ball check valve.
[0037] The hydraulic valve 1 includes a valve housing 2 and a valve piston 4 that is axially moveable along a longitudinal axis 3 of the valve housing 2 . In order to move the valve piston 4 a first face 5 of the valve piston 4 that is oriented away from the internal combustion engine is closed so that a plunger that is not illustrated in more detail of an electromagnetic linear actuator that is not illustrated in more detail can contact the first face 5 . Providing power to the linear actuator leads to an axial movement of the valve piston 4 towards the internal combustion engine, wherein a retaining element 7 arranged at a second face 6 of the valve piston 4 which is configured oriented away from the first face 5 imparts a reset force upon the valve piston 4 against which reset force the valve piston 4 has to be moved. The retaining element 7 configured in this embodiment as a compression coil spring is supported at a hollow cylinder 8 which is arranged in the portion of the second face 6 with a press fit and non moveable in the valve housing 2 .
[0038] The valve piston 4 is configured flowable and includes a channel system 14 with a supply channel 15 and a channel groove 16 intersecting the supply channel. The supply channel 15 extends along a longitudinal axis of the valve piston 4 which longitudinal axis is configured coaxial to the longitudinal axis 3 , wherein the supply channel 15 is closed at a first channel end 17 oriented towards the first face and open at a second channel end 18 oriented towards the second face 6 so that hydraulic fluid can flow into the supply channel 15 through an inlet opening 19 of the valve piston 4 configured at the second channel end 18 .
[0039] The channel group 16 is configured as intersecting bore holes, wherein each bore hole extends completely over a diameter D of the valve piston 4 and forms two respective outlet openings 21 at an enveloping surface 20 of the valve piston 4 . The bore holes are arranged star shaped, wherein they form a joint intersection surface which is arranged flowable in the supply channel 15 .
[0040] The valve housing 2 which is configured bushing shaped includes a supply connection P, a first operating connection A, a second operating connection B, a first tank access T 1 and a second tank access T 2 which are respectively configured flowable. The first operating connection A and the second operating connection B are connected with accordingly associated pressure chambers of the cam phaser so that the hydraulic fluid can load the pressure chambers in a manner controlled by the hydraulic valve 1 .
[0041] A first channel 10 in the valve housing 2 is associated with the first operating connection A and a second channel 11 in the valve housing 2 is associated with the second operating connection B, wherein the operating connections facilitate loading the channels 10 , 11 with the hydraulic fluid flowing through the hydraulic valve using a first opening 23 and a second opening 24 configured at an inner surface 22 of the valve housing 2 , which inner surface is oriented towards the valve piston 4 .
[0042] Depending on a selected direction of rotation the hydraulic fluid flows in or out of the pressure chambers. Thus, for example in the position of the valve piston illustrated in FIG. 1 the pressure chambers associated with the operating connection B are loaded with the hydraulic fluid. In this position of the valve piston 4 , the hydraulic fluid flows out of the supply connection P through a check valve 13 arranged in an inflow channel 12 of the valve housing 2 , which inflow channel is configured between the supply connection P and the hollow cylinder 8 , and through the hollow cylinder 8 through the inlet opening 19 into the supply connection 15 .
[0043] The outlet openings 21 at least partially cover the second opening 24 so that the hydraulic fluid can flow out of the supply channel 15 through the outlet openings 21 and the second opening 24 into the second channel 11 through the second operating connection B into the respective pressure chambers.
[0044] The pressure chambers associated with the second operating channel B are thus loaded with the hydraulic fluid. This has the effect that hydraulic fluid exits the pressure chambers associated with the first operating connection A, wherein the hydraulic fluid flows from the first channel 10 through its first opening 23 and a first gap 25 arranged between the enveloping surface 20 and the inner surface 22 into a third channel 26 which includes a third opening 27 arranged at an inner surface 22 wherein the third channel 26 is connected with the first tank access T 1 for relief, this means for draining the hydraulic fluid.
[0045] The second tank access T 2 through which the hydraulic fluid can flow from the second channel 11 when the valve piston 4 is positioned accordingly is arranged in a portion of the cam phaser downstream of the first face 5 .
[0046] In a non-illustrated additional position of the valve position 4 , the valve piston 4 is axially moved in a direction towards the internal combustion engine so that the first gap 25 is closed whereas an axially opposite second gap is configured between the first opening 23 and the enveloping surface 20 , wherein the outlet openings 21 now at least partially cover the first opening 23 . Through this second gap the hydraulic fluid can flow through the outlet openings 21 out of the supply channel 15 into the first opening 23 and thus into the first channel 10 . From the first channel 10 the hydraulic fluid flows through the first operating connection A into the pressure chambers associated with the first operating connection A wherein the pressure chambers are loaded with the hydraulic fluid.
[0047] As a consequence of this loading hydraulic fluid exits the pressure cavities associated with the second operating connection B wherein the hydraulic fluid flows out of the second channel 11 through its second opening 24 and a third gap which is configured between the enveloping surface 20 and the inner surface 22 so that the hydraulic fluid eventually flows into the second tank access T 2 .
[0048] The supply connection P is configured to be connected with an oil pump which is not illustrated in more detail so that the hydraulic valve 1 is flowable with hydraulic fluid which is oil in this embodiment.
[0049] The supply connection P is arranged at a housing face of the valve housing 2 which housing face is oriented towards the internal combustion engine. In order to prevent a back flow of the hydraulic fluid from the valve housing 2 to the supply connection P a check valve 13 is arranged in the inflow channel 12 . The check valve 13 is configured as a ball check valve and fixated in the valve housing 2 by a retaining element 29 configured as a Seeger ring and by a form element 47 wherein the retaining element is axially supported at a first annular shoulder 28 configured in a supply channel 12 .
[0050] A hydraulic valve 1 according to the invention is configured according to FIG. 2 . A detail drawing for illustrating the check valve 13 depicts a longitudinal sectional view of a detail of the hydraulic valve 1 according to the invention in FIG. 3 . The check valve 13 is configured disc shaped including a first disc shaped closure element 30 which is fixated in the inflow channel 12 downstream of the supply connection P in the valve housing. Between the valve piston 4 and the first closure element 30 a disc shaped second closure element is moveably received in the inflow channel 12 . The first closure element 30 is configured independent from the second closure element 31 . The two closure elements 30 , 31 are positioned in the inflow channel 12 so that a first inflow surface 40 of the first closure element 30 and a second inflow surface 41 of the first closure element 30 which is oriented away from the first inflow surface 40 or a third inflow surface 42 of the second closure element 31 and a fourth inflow surface 43 of the second closure element 31 that is oriented away from the third inflow surface 42 are oriented parallel to a flow cross section 44 of the inflow channel 12 .
[0051] The first closure element 30 is secured against axial movement by the first annular shoulder 28 in the inflow channel 12 and by the retaining element 29 and the formed element 47 . Additionally a radial rotation of the first closure element 30 is blocked through a press fit of the first closure element 30 in the inflow channel 12 .
[0052] Like typical check valves the check valve 13 opens when a pressure of the hydraulic fluid upstream of the check valve 13 is greater than a pressure downstream of the check valve 13 wherein the flow direction is counted from the direction of the supply connection P. FIG. 2 illustrates the hydraulic valve 1 according to the invention in a position in which the check valve 13 is flowable.
[0053] The hydraulic fluid presses the second closure element 31 against the hollow cylinder 8 where it is supported. A spring element 32 supported at the hollow cylinder 8 by a second shoulder 45 configured in the hollow cylinder 8 is arranged oriented towards the second closure element 31 for establishing contact and is preloaded in this position.
[0054] In closed condition the hydraulic fluid can flow in arrow direction PR from the supply connection P through a first pass through opening 33 of the first closure element 30 into the inflow channel 12 and from there through the second closure element 31 through its second pass through opening 34 so that the hydraulic fluid can enter the supply channel 15 through the hollow cylinder 8 .
[0055] When sizing the second pass through opening 34 care has to be taken that its diameter is on the one hand side smaller than a smallest diameter configured in the hollow cylinder 8 and on the other hand side that it is large enough so that the hydraulic fluid can flow into the valve piston 4 in a sufficiently short time period also at high engine speeds. The advantage of sizing the diameter of the second pas through opening 34 smaller is that hydraulic fluid flowing out of the valve piston 4 in a direction towards the check valve 13 at least partially directly impacts the third inflow surface 42 and can move the third inflow surface against the first closure element 30 so that closing the check valve 13 is accelerated.
[0056] The first pass through opening 33 is configured in an annular first outer section 35 of the first closure element 30 , wherein the term “outer section” is thus interpreted so that a radial distance of the outer section 35 from a center of the first closure element 30 is greater than a radial distance of the first inner section 36 of the first closure element 30 . The first pass through opening 33 is divided into four pass through opening sections by bars 46 , wherein the bars 46 are required to implement a simple configuration of the first closure element 30 and are only used for defining the first pass through opening 33 in radial direction. The first pass through opening 33 is configured groove shaped providing an effective flow cross section with maximum size in the first outer section 35 , c.f. FIG. 4 .
[0057] The second closure element 31 is configured not flowable in its second outer section 37 , wherein its second inner section 38 is flowable and includes the circular second pass through opening 34 . Put differently the second closure element 31 is configured as a circular disc, cf. FIG. 5 .
[0058] The pass through openings 33 , 34 are arranged to that the first pass through opening 33 is arranged opposite to the non flowable second outer section 37 and the second pass through opening 34 is arranged opposite to the un flowable first section 36 .
[0059] In case a pressure downstream of the check valve 13 is greater than a pressure upstream of the check valve 13 or in case a pressure spike due to cam phasing moments downstream of the check valve 13 impacts the second closure element 31 , the second closure element 31 is pressed onto the first closure element 30 through a force of the pressure spike impacting a third inflow surface 42 of the second closure element 31 oriented towards the valve piston 4 , so that accordingly positioned pass through openings 33 , 34 are blocked by the respective other closure element 31 , 30 so that they are not flowable.
[0060] The axially moveable second closure element 31 is supported in a sliding bearing in a radial direction at its circumference in the inflow channel 12 so that a wear caused by cavitation or abrasion is very small depending on an axial thickness d of the second closure element 31 . The axial thickness d can be kept very small since the second closure element 31 performing its sealing function only has to cover the first pass through openings 33 with a fourth inflow surface 43 of the second closure element since the second closure element 31 is pressed against the first closure element 30 due to a pressure acting downstream.
[0061] The shape of the first closure element 30 and of the second closure element 31 illustrated in this embodiment and of the accordingly configured pass through openings 33 , 34 facilitates advantageous sizing of the pass through openings 33 , 34 so that sufficient hydraulic fluid can flow from the supply connection P into the valve piston 4 also under high engine speeds so that a quick response of the hydraulic valve 1 or a quick reaction time or switching time is implemented.
[0062] It is also favorable for a quick reaction time to use appropriate materials to implement a low weight of the moveable second closure element 31 .
[0063] The spring element 32 supports the axial movement of the second closure element 31 and presses the second closure element 31 against the first closure element 30 which supports safe closure. Using the spring element 32 significantly improves responsiveness of the hydraulic valve 1 due to improved dynamics of the check valve 13 over known check valves. Additionally the spring element 32 helps to dampen pressure spikes which can occur in the inflow channel 12 coming from the supply connection P and thus achieves loading the valve piston 4 by the hydraulic fluid without pressure spikes.
[0064] FIG. 6 illustrates the first closure element 30 and the second closure element 31 in a longitudinal sectional view in a first relative position. Depending on the pressures applied at the check valve 13 the second closure element 31 moves in an axial direction. When a pressure caused by pressure spikes on a side of the check valve 13 is greater than a pressure on a side of the supply connection P the second closure element 31 impacts the first closure element 30 until a sealing contact is established between the first closure element 30 and the second closure element 31 .
[0065] Improved sealing of the check valve 13 can be achieved by a seal element 39 between the first closure element 30 and the second closure element 31 . According to a second embodiment, c.f. FIG. 7 the seal element 39 is configured at the first inflow surface 40 arranged opposite to the second closure element 31 . By the same token the sealing element 39 can be arranged at a fourth inflow surface 43 arranged opposite to the first closure element 30 as illustrated in the third embodiment according to FIG. 8 .
REFERENCE NUMERALS AND DESIGNATIONS
[0000]
1 hydraulic valve
2 valve housing
3 longitudinal axis
4 valve piston
5 first face
6 second face
7 retaining element
8 hollow cylinder
9 housing face
10 first channel
11 second channel
12 inflow channel
13 check valve
14 channel system
15 supply channel
16 channel group
17 first channel end
18 second channel end
19 inlet opening
20 enveloping surface
21 outlet opening
22 inner surface
23 first opening
24 second opening
25 first gap
26 third channel
27 third opening
28 first shoulder
29 safety element
30 first closure element
31 second closure element
32 spring element
33 first pass through opening
34 second pass through opening
35 first outer section
36 first inner section
37 second outer section
38 second inner section
39 sealing element
40 first inflow surface
41 second inflow surface
42 third inflow surface
43 fourth inflow surface
44 flow cross section
45 second shoulder
46 bar
47 form element
[0113] A first operating connection
[0114] B second operating connection
[0115] D diameter
[0116] D 1 first diameter
[0117] D 2 second diameter
[0118] P supply connection
[0119] PR arrow direction
[0120] T 1 first tank access
[0121] T 2 second tank access
d thickness | A hydraulic valve for a cam phaser including a valve housing with a longitudinal axis and a valve piston that is axially moveable along the longitudinal axis, wherein the valve piston opens and closes a first operating connection of the valve housing and a second operating connection of the valve housing, wherein the first operating connection and the second operating connection are axially offset from one another; and a supply connection of the valve housing which is used for supplying the hydraulic valve with a hydraulic fluid fed by a feed device, wherein the hydraulic valve is configured to be flowed through by the hydraulic fluid on different paths controlled by a flow permeable channel system of the valve piston, and wherein a check valve opening and closing an inflow channel is arranged in the hydraulic valve in the inflow channel of the valve housing. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 60/837,762 filed Aug. 15, 2006, entitled Replacement Torque Converter Cover Assembly.
BACKGROUND OF INVENTION
The present invention relates to automotive transmission systems and, more particularly, to a replacement torque converter cover for an ALLISON MT 600 series (hereinafter “ALLISON”) transmission or other similar transmissions.
The torque converter of an automatic transmission replaces the clutch used in manual transmissions. It is the primary component for transmittal of power between the engine and the transmission in an automotive vehicle. The basic principle of torque converter operation can be observed by placing the blades of two electric fans opposite each other and turning on one of the fans. If one of the fans is turned on, the force of the air column produced will act upon the motionless blades of the other fan, which will begin turning and eventually reach a speed approaching the speed of the powered fan. The torque converter employs an analogous mechanism using automatic transmission fluid (hereinafter “ATF”) to provide a fluid coupling between the engine and the transmission of an automobile, which provides for a smooth conversion of torque from the engine to the mechanical components of the transmission.
In the ALLISON transmissions a drum-shaped, torque converter cover is connected by threaded studs to the engine flywheel at its forward end and is also bolted to the torque converter impeller (hereinafter “impeller”) so that the impeller will rotate at engine speed. It is known in the industry that when such ALLISON transmissions are installed in commercial duty vehicles having a high torque, diesel engine such as trucks, buses, equipment haulers, and tractors, the structural strength of the original equipment manufacture (hereinafter “OEM”) torque converter cover is often inadequate and, as a result, failure of the cover often occurs during converter lock-up and other peak torque events.
In addition, such commercial vehicles are often permitted to run at idle for extended periods of time. Because such diesel engines run unevenly at low speeds, mechanical fretting of torque converter components may result in structural damage. This is a particular problem in vehicles with the ALLISON MT 600 transmission wherein the lock-up clutch in the torque converter lacks a dampening mechanism, which results in high impact loads being imparted to the torque converter cover studs.
Thus, the present invention has been developed to resolve this problem and other shortcomings of the prior art.
SUMMARY OF THE INVENTION
Accordingly, the present invention is a replacement torque converter cover (hereinafter “replacement cover”) for an ALLISON MT 600 transmission or other similar transmission. The present replacement cover is designed to withstand the mechanical stresses generated in the torque converter lock-up clutch during peak torque events when such transmissions are utilized with diesel engines and other high-torque truck engines.
The OEM cover includes through-drilled holes for receiving threaded stud pins, which function to attach the cover to the engine flexplate externally and to continuously drive the clutch piston internally during all modes of operation. The present replacement cover provides a redesigned lock-up clutch interface (i.e. piston contact surface) wherein such through-drilled holes for receiving threaded stud pins are eliminated. Any such discontinuity (i.e. through-drilled hole) in a machine part alters the stress distribution in the vicinity of the discontinuity and is prone to stress cracking. Accordingly, stress concentration and mechanical fatigue in the present replacement cover is substantially reduced.
The present replacement cover also provides increased structural strength having a piston contact (i.e. working) surface of an increased axial thickness. The present replacement cover provides separate threaded studs and stud pin components for installation on the opposite sides of such piston working surface for engagement with the OEM flexplate and clutch piston respectively.
There has thus been outlined, rather broadly, the important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.
Those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods, and systems for carrying out the purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
Other features and technical advantages of the present invention will become apparent from a study of the following description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features of the present invention are set forth in the appended claims. The invention itself, however, as well as other features and advantages thereof will be best understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures, wherein:
FIG. 1 is a longitudinal cross-section view of an ALLISON MT 600 torque converter assembly illustrating the internal components thereof and is labeled Prior Art;
FIG. 2 is a partial longitudinal cross-section view of the ALLISON MT 600 torque converter assembly and is labeled Prior Art;
FIG. 3 is an enlarged, partial longitudinal cross-section view of the ALLISON MT 600 torque converter assembly and is labeled Prior Art;
FIG. 4 is a top plan view of the replacement torque converter cover assembly of the present invention;
FIG. 5 is a longitudinal cross-section taken along section line 5 - 5 of FIG. 4 ;
FIG. 6A is an enlarged detail view showing a threaded stud of the present invention installed in the present replacement cover;
FIG. 6B is an enlarged detail view showing a drive pin of the present invention installed in the present replacement cover; and
FIG. 7 is a partial longitudinal cross-section of the present replacement cover showing a drive pin in engagement with the OEM lock-up piston.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Prior to describing the present invention in detail, it may be beneficial to briefly review the structure and function of the OEM torque converter assembly of an ALLISON MT 600 transmission wherein the present invention is utilized. With further reference to the drawings there is shown therein a cross-sectional view of such a torque converter assembly, indicated generally at 100 and illustrated in FIG. 1 , which is the primary component for transmittal of power between the engine and the automatic transmission in an automotive vehicle. The torque converter assembly 100 provides for a smooth conversion of torque from the engine to the mechanical components of the automatic transmission and also functions to multiply torque from the engine enabling the vehicle to achieve additional performance when necessary.
Torque converter assembly 100 is comprised of the following main sub-assemblies: (1) an impeller assembly, indicated generally at 105 , which is the driving member; (2) a turbine assembly, indicated generally at 110 , which is the driven member; (3) a stator assembly, indicated generally at 115 , (4) a lock-up clutch assembly, indicated generally at 120 , which engages the turbine assembly 110 to enable direct mechanical drive; and (5) a front cover assembly (hereinafter “cover”), indicated generally at 125 , which is attached to the impeller assembly 105 as at 150 .
Cover 125 is also attached to the engine flexplate (not shown) by threaded stud pins 140 that are mechanically attached to the engine flexplate so that the cover 125 will rotate at engine speed. Cover 125 includes a cover pilot 127 on a forward-facing surface thereof to center the torque converter assembly 100 in coaxial relation to the engine crankshaft (not shown).
When the engine is running, the impeller assembly 105 acts as a centrifugal pump by picking up ATF at its center and discharging it at its rim. The force of the ATF flow from the impeller assembly 105 is directed into the turbine assembly 110 and causes it to rotate. As the engine and impeller assembly 105 increase in speed, so does the turbine assembly 110 including turbine shaft 112 to mechanically operate the transmission.
The lock-up clutch assembly 120 includes a lock-up piston 142 having a plurality of pin receptacles 145 ( FIG. 2 ) formed within a forward facing surface thereof for engagement with the mating stud pins 140 extending through holes 126 which are drilled through the radial wall 125 a of cover 125 as most clearly shown in FIG. 3 . The lock-up clutch assembly 120 also includes a circular friction plate 144 for frictional engagement with a concentrically disposed backing plate 146 . Lock-up piston 142 is also mechanically attached to the turbine hub 111 ( FIG. 1 ).
When lock-up is required the contact surface of lock-up piston 142 flexes axially rearward in response to increased ATF pressure within lock-up clutch 120 . Axial flexion of piston 142 is guided by pins 140 within mating receptacles 145 of piston 142 compressing friction plate 144 against backing plate 146 ( FIG. 1 ) to provide a direct mechanical coupling of the engine to the transmission during the torque converter lock-up cycle. When the lock-up clutch assembly 120 is applied, the slippage that occurs through the fluid coupling is eliminated providing a direct mechanical drive path from the engine to the transmission.
More particularly, when the lock-up piston 142 is installed within the cover 125 as most clearly shown in FIG. 2 , a clutch apply chamber 170 is formed between the cover 125 and the piston 142 . When fluid pressure in the clutch apply chamber 170 exceeds the spring preload force of the piston web 142 a , the contact surface of piston 142 is flexed axially rearward compressing the friction plate 144 between piston 142 and backing plate 146 ( FIG. 1 ) to initiate the lock-up cycle.
When converter lock-up is no longer required, a port opens that allows pressurized ATF to flow out of the clutch apply chamber 170 thereby releasing the lock-up piston 142 which is flexed in the reverse direction to end the lock-up cycle.
It is known in the industry that when the ALLISON transmissions are utilized with a high-torque, diesel engine, the structural strength of the OEM cover 125 is inadequate and, as a result, structural failure of the cover often occurs. Such structural failure is due in substantial part to the presence of the through-drilled holes 126 ( FIG. 3 ) formed in the OEM cover 125 and weldment of the threaded stud pins 140 in position within such holes 126 to attach the cover 125 to the engine flexplate. Any such discontinuity (e.g. through-drilled holes 126 ) in a machine part alters the stress distribution in the vicinity of the discontinuity and is prone to stress fractures or cracks. Such discontinuities are called stress raisers, and the portions of the part in which they occur are called areas of stress concentration.
The rotational torque force and mechanical stress imposed on the OEM cover 125 at engine idle and other peak torque events produces stress fractures in the cover in proximity to holes 126 and adjacent to stud pins 140 , which are attached to cover 125 by weldment. Once a crack is initiated, the stress concentration effect becomes greater and the cracks progress more rapidly, which results in ATF leakage from the apply chamber 170 . As the stress increases in magnitude, that portion of the radial wall 125 a in proximity to holes 126 fails, which results in excessive ATF leakage and malfunction of the hydraulic system.
Further, the necessary clearance between stud pins 140 and pin receptacles 145 permits rotational oscillation of the piston 142 against the stud pins 140 imparting high impact loads to the stud pins. The effect of such impact against stud pins 140 is exacerbated due to the fact that the ALLISON MT 600 transmission lacks a dampening mechanism to counteract such high impact loads. Eventually stud pins 140 become loosened and are dislodged from cover 125 causing malfunction of the lock-up clutch 120 .
Thus, the present invention has been developed to resolve this problem and other shortcomings of the prior art and will now be described. Referring to FIGS. 4 and 5 there is shown therein a replacement cover assembly in accordance with the present invention, indicated generally at 10 . The present replacement cover 10 is machined from a high grade steel forging in accordance with American Iron and Steel Institute (AISI 1026) or other suitable material.
Replacement cover 10 comprises a drum-shaped member having a radial wall 20 extending in generally perpendicular relation to the longitudinal axis -A- ( FIG. 5 ). An integral cylindrical portion 15 including flange 15 a of the cover 10 extends axially from the radial wall 20 in concentric relation to axis -A-.
In the embodiment shown the present cover 10 includes a set of six threaded studs 40 installed in a concentric array at angular intervals of 60 degrees on a forward-facing surface of the cover ( FIG. 4 ). In addition, the present cover 10 includes a set of six drive pins 45 also installed in a concentric array at angular intervals of sixty degrees on an opposite, rearward-facing surface of the cover 10 . In the preferred embodiment both threaded studs 40 and drive pins 45 are fabricated from high quality steel or other suitable material for this purpose.
Still referring to FIG. 4 it can be seen that the array of six drive pins 45 is oriented at a thirty degree angular offset to the array of threaded studs 40 such that each drive pin 45 is equidistant from each threaded stud 40 . More particularly, in the present invention each threaded stud 40 is installed in a mating threaded hole 42 as shown in FIG. 6A and after threaded engagement therein is permanently captured by weldment at the base of studs 40 . Thereafter, each remaining weld bead is ground flush with a forward-facing surface of radial wall 20 as at 35 ( FIG. 6A ).
Referring to FIG. 6B each drive pin 45 is installed to an interference fit within a blind hole 46 formed on the inner surface of radial wall 20 of cover 10 to a predetermined depth corresponding to an axial stack-up length -L- ( FIG. 5 ) for threaded stud 40 and drive pin 45 assembled in cover 10 . It will be noted that the axial stack-up length -L- is equivalent to the overall length -OAL- ( FIG. 3 ) of OEM stud pins 145 . Such axial stack-up length -L- is critical for maintaining the functional position of the lock-up clutch assembly 120 during normal operation of the transmission.
It will also be noted that the axial length (i.e. thickness) -AL′- of the present radial wall 20 ( FIGS. 6A and 6B ) has been substantially increased in comparison to the axial length (i.e. thickness) -AL- of the radial wall 125 a of the OEM cover 125 ( FIG. 3 ) to provide added structural strength and durability to the present replacement cover 10 .
Although not specifically illustrated in the drawings, it should be understood that additional equipment and structural components will be provided as necessary and that all of the components described above are arranged and supported in an appropriate fashion to form a complete and operative Replacement Torque Converter Cover Assembly incorporating features of the present invention.
Moreover, although illustrative embodiments of the invention have been described, a latitude of modification, change, and substitution is intended in the foregoing disclosure, and in certain instances some features of the invention will be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of invention.
Having described preferred embodiments of our invention, what we desire to secure by U.S. Letters Patent is: | A replacement torque converter cover designed to withstand mechanical stresses generated in the torque converter lock-up clutch of ALLISON transmissions when such transmissions are utilized with diesel engines and other high-torque truck engines. The original equipment cover includes through-drilled holes for receiving unitary threaded stud pins, which function to attach the cover to the engine crankshaft externally and to drive the lock-up clutch piston internally during operation. The present replacement cover provides a lock-up clutch piston interface wherein such through-drilled holes and unitary threaded stud pins are eliminated, which substantially reduces stress concentration and mechanical fatigue in the replacement cover. In comparison to the unitary threaded stud pins of the original equipment cover, the present replacement cover provides separate threaded stud and drive pin components respectively, which are installed at radially offset positions on opposite sides of a modified radial wall having an increased axial thickness and improved durability. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority from India Application 3024/CHE/2011, filed Sep. 2, 2011, entitled Process for the Preparation of Sucralose, which application is assigned to the same assignee as this application and whose disclosure is incorporated by reference herein.
FIELD OF INVENTION
The present invention relates to an improved process for the preparation of colorless sucralose.
BACKGROUND OF THE INVENTION
Sucralose (4,1′,6′-trichloro-4,1′,6′-trideoxy-galactosucrose, or 1,6-dichloro -1,6-dideoxy-β-D-fructofuranosyl-4-chloro-4-deoxy-α-D-galactopyranoside) is an artificial sweetener derived from sucrose. It is about 600 times sweeter than cane sugar. It is considered safe because it is excreted in humans without undergoing any metabolism. It has high resistance to acid hydrolysis and is highly stable to heat. Because of these advantages, sucralose is one of the most widely used sweeteners in the market.
Synthesis of sucralose involves substitution of two primary alcohol groups at the 1′ and 6′ positions and a secondary alcohol group at the 4 position with chlorine. During the chlorination (for the sake of simplicity this reaction will be referred henceforth as ‘chlorination’) the other primary alcohol group at the 6-position should not be affected. This is generally achieved by selective esterification of a primary alcohol at the 6 position before chlorination. Finally the ester is hydrolyzed to obtain sucralose.
The Tate & Lyle group has developed a method for the preparation of sucrose-6-acetate selectively through an ortho ester intermediate (U.S. Pat. No. 4,889,928).
Chlorination of sucrose-6-acetate is a typical S N 2 substitution reaction resulting in inversion of the configuration at the 4-position. Because of this inversion, the glucose ring gets converted to a galactose ring. Thus, trichlorination of sucrose-6-acetate gives 4,1′,6′-trichloro-4,1′,6′-trideoxy-galactosucrose-6-acetate (TGS-6-acetate) In most cases, a Vilsmeier type reagent is preferred for the trichlorination of sucrose-6-acetate (U.S. Pat. Nos. 4,380,476; 4,617,269; and 4,980,463). U.S. Pat. No. 4,980,463 describes the use of a Vilsmeier reagent prepared from phosgene and dimethylformamide (DMF) for the chlorination of sucrose-6-acetate. Triphosgene, which is a safer alternative to phosgene, has been used for the preparation of a Vilsemeier reagent from DMF. (US 2008/0103298 A1). Chlorination of sucrose-6-ester with a Vilsmeier reagent is a complex reaction. For the chlorination at all three positions, a temperature of about 100-120° C. is required and the reaction is to be maintained at this temperature for several hours. The severe conditions required for complete chlorination results in a dark brown to black reaction mass. Irrespective of the workup methods, the TGS-6-acetate is always obtained as a highly colored product. Almost all reported methods describe the use of activated charcoal for the decolorization (US 2007/0207246A1; US 2008/0300401 A1; US 2008/0103298A1). US application US 2007/0207246A1 describes a process where TGS-6-acetate was decolorized using activated charcoal and after ester hydrolysis, the final sucralose product needed to be again decolorized using charcoal. The application US 2008/0300401A1 describes a process where TGS-6-acetate was decolorized twice using activated charcoal and after ester hydrolysis, the final sucralose product was again decolorized using charcoal for a third time.
TGS-6-acetate is hydrolyzed to sucralose using a base such as sodium methoxide (U.S. Pat. No. 4,380,476, US 2009/0227783), sodium hydroxide (U.S. Pat. No. 5,498,709), potassium hydroxide (US 2007/0207246) or an organic base such as triethylamine (U.S. Pat. No. 7,838,642). When sodium methoxide is used, the conversion remains incomplete. Hydrolysis using organic base is also slow and the acetate salts of the organic bases formed in the reaction have similar solubility as sucralose and their removal is difficult.
Thus, there is a strong need for an efficient process to decolorize TGS-6-acetate and sucralose. There is also a need for a rapid method for the hydrolysis of TGS-6-acetate to obtain sucralose.
SUMMARY OF THE INVENTION
While exploring various alternatives to the existing cumbersome charcoal treatment for procuring colorless sucralose, we argued that decolorization of TGS-6-acetate followed by hydrolysis may result in a colorless sucralose. We then found that the highly colored TGS-6-acetate, obtained after the chlorination of sucrose-6-acetate, can be completely decolorized by treating it with a sodium hypochlorite solution. Surprisingly, the decolourization process was very rapid, almost instantaneous. As a further surprise, we found that the treatment with sodium hypochlorite also resulted in the hydrolysis of the ester group giving sucralose directly.
Thus, the present invention discloses a process in which the treatment of highly colored TGS-6-acetate with sodium hypochlorite results both in efficient decolourization of TGS-6-acetate and also ester hydrolysis, simultaneously in one step, to give colorless sucralose.
DETAILED DESCRIPTION OF THE INVENTION
According to the present invention, there is provided a process for the preparation of sucralose, which comprises:
a) reacting sucrose-6-acetate with a Vilsmeier type reagent to obtain 4,1′,6′-trichloro-4,1′,6′-trideoxy-galactosucrose-6-acetate (TGS-6-acetate); and b) treating the TGS-6-acetate so obtained with sodium hypochlorite to obtain colorless sucralose.
The required starting material, sucrose-6-acetate, can be prepared from sucrose as described in U.S. Pat. No. 4,889,928 incorporated y reference in its entirety herein or by any other suitable method. In one aspect of the invention, sucrose-6-acetate is dissolved in a polar solvent and chlorinated using a Vilsmeier type reagent. For this reaction, dimethylformamide (DMF) is the solvent of choice. DMF not only generates a Vilsmeier reagent with a chlorinating agent, but also is a good solvent for sucrose-6-acetate. Further, the DMF with its aprotic nature and high boiling point is also a good solvent for the nucleophilic substitution reaction. The chlorinating agent for the preparation of the Vilsmeier reagent from DMF can be thionyl chloride, phosphorus oxychloride (POC13), oxalyl chloride, phosgene, triphosgene and the like. Phosphorus oxychloride is expensive while oxalyl chloride decomposes to poisonous carbon monoxide. When thionyl chloride/DMF is used for the generation of the Vilsmeier reagent, a high amount of charred material is observed at higher temperature. Phosgene is highly poisonous and being a gas, difficult to handle on a large scale. Triphosgene, which is a solid and a safer alternative to phosgene, is preferred. Using the Vilsmeier reagent prepared from triphosgene/DMF results in efficient and complete chlorination. Addition of triphosgene to a solution of sucrose-6-acetate in DMF results in a highly exothermic reaction. Cooling of sucrose-6-acetate solution to −10° C. and gradual addition of triphosgene as a solution helps in controlling the exothermic reaction. On addition, a Vilsmeier type salt or N,N-dimethylchloroforminium chloride is formed which is poorly soluble at low temperatures. Stirring of the resulting suspension should be efficient to prevent settling down of the reagent. Improper stirring results in poor yields. The temperature of the reaction is gradually raised. At about 80° C., the reaction mixture is a clear solution, but is colored. The temperature is further raised to 115±5° C. During this stage the solution turns dark brown to black. The reaction has to be maintained at this temperature for 4 to 6 hours for complete chlorination. After completion of the reaction, the reaction mixture is cooled to about 0° C. and neutralized to pH 7.0 with ammonium hydroxide to decompose excess triphosgene. Most of the solvent is removed by distillation under reduced pressure at 60-65° C. The crude oily syrup obtained is dissolved in water and extracted with an organic solvent such as ethyl acetate. Evaporation of solvent under reduced pressure results in crude TGS-6-acetate as a black oily material. It is dissolved in a water miscible solvent, cooled to 0° C. and treated with a solution of sodium hypochlorite. The water miscible solvent can be an alcohol or an aprotic solvent. The alcohol can be methanol, ethanol, propanol and the like, and the aprotic solvent can be tetrahydrofuran, dioxane, DMF, dimethylsulfoxide (DMSO) and the like. Out of all the solvents tried, methanol was found to be ideal. When water was used, the yields were low. Sodium hypochlorite solution of about 15% w/v strength was prepared according to Org. Syn. Coll. Vol. 1, 1941, 309-310. Sodium hypochlorite solution is added till the reaction mixture is alkaline (pH>12.0±0.5). On addition of the sodium hypochlorite solution, the black reaction mixture turns colorless. The decolourization is instantaneous and takes place within a few minutes. Simultaneously, the process of ester hydrolysis also starts and formation of sucralose can be detected by TLC using chloroform: methanol (5:1) as a solvent system and sulphuric acid spray for detection. The hydrolysis step is slow and maximum yields are obtained after about 4.0±0.5 hours. Longer periods did not improve the yields. About 10% starting material still remains, which can be recovered during the workup and reused. As the reaction progresses, the pH decreases and more sodium hypochlorite solution is added to maintain the pH at 12.0±0.5. If the pH is not maintained, the yields will decrease. The reaction temperature also plays an important role. At low temperatures (0±5° C.), the reaction goes smoothly and gives the best results. At ambient (25±5° C.) and higher temperatures, consumption of sodium hypochlorite increases many folds and the purity of sucralose obtained also is affected. After the reaction, the pH is adjusted to 7.0 using an acid such as acetic acid and all solvents are removed under reduced pressure at 45-50° C. The colorless solid so obtained is dissolved in water. From the aqueous solution, unreacted TGS-6-acetate can be recovered by extracting with methylene chloride or methyl tert-butyl ether. Sucralose is obtained by extracting the aqueous solution with ethyl acetate. Sucralose thus obtained is a foamy colorless solid containing a high amount of moisture. Recrystallization using n-butyl formate gives white crystalline sucralose (>99% HPLC) with moisture <0.5%.
The embodiments of the present invention are illustrated in the following examples, which do not in any way limit the scope of the invention.
EXAMPLES
Example: 1
Sucrose-6-acetate (72 g, 0.163 mol) was dissolved in 720 ml DMF and cooled to −10° C. Triphosgene (170.2 g, 0.653 mol) in 960 ml toluene was added drop wise and stirred for 1 hr at −10° C. The reaction mixture was heated slowly and maintained at 115±5° C. for 5 hr. After cooling to 0-5° C., the reaction mixture was neutralized to pH 7.0 with NH 4 OH solution. Most of the solvent was removed by distillation under reduced pressure at60-65° C. The black crude syrup obtained was dissolved in 300 ml water. It was extracted with ethyl acetate (100 ml×3). Pooled ethyl acetate layers were concentrated under reduced pressure to get TGS-6-acetate as a black oily material. It was dissolved in 300 ml methanol, cooled to 0-5° C., and treated with a solution of sodium hypochlorite (15%) till the pH was 12.0±0.5. The reaction mixture turned colorless. The reaction was maintained at pH 12.0±0.5 for 4.0±0.5 hours by adding an additional amount of sodium hypochlorite solution. The reaction was neutralized to pH 7.0 using acetic acid. All solvents were removed under reduced pressure at 45-50° C. The colorless solid obtained was dissolved in water (200 ml) and washed with methyl tert-butyl ether (MTBE, 50 ml×3) to remove the unreacted TGS-6-acetate. The aqueous solution was extracted with ethyl acetate (100 ml×3). After drying over Na 2 SO 4 , the ethyl acetate layer was concentrated under reduced pressure at room temperature to obtain sucralose as a colorless foamy solid. It was recrystallized using n-butyl formate. Yield: 48 g (64.8%, 99.5% HPLC, 0.3% moisture).
Example: 2
Sucrose-6-acetate (72 g, 0.163 mol) was converted to TGS-6-acetate as in example-1.The black crude syrup of TGS-6-acetate obtained (as in example 1) was dissolved in 300 ml water, cooled to 0-5° C. and treated with a solution of sodium hypochlorite (15%) till the pH is 12.0±0.5. The reaction mixture turned colorless. The reaction was maintained at pH 12.0±0.5 for 4.0±0.5 hours by adding more sodium hypochlorite solution and neutralized to pH 7.0 using acetic acid. Solvents were removed under reduced pressure at 45-50° C., the colorless solid obtained was dissolved in water (200 ml) and washed with MTBE (50 ml×3) to remove the unreacted TGS-6-acetate. The aqueous solution was extracted with ethyl acetate (100 ml×3). After drying over Na 2 SO 4 , the ethyl acetate layer was concentrated under reduced pressure at room temperature to obtain sucralose as a colorless foamy solid. It was recrystallized using n-butyl formate. Yield: 31.2 g, (42.2%).
Example: 3
Sucrose-6-acetate (10 g, 0.026 mol) was dissolved in 100 ml DMF. Separately thionyl chloride (42.6 g, 0.35 mol) was dissolved in 50 ml ethylene dichloride. Both solutions were cooled to 0-5° C. The thionyl chloride solution was added slowly to sucrose-6-acetate solution and stirred for one hour. The reaction was heated and maintained at 115±5° C. for about 6 hr till the starting material was completely consumed (TLC). After cooling to 0-5° C., the reaction mixture was neutralized to pH 7.0 with NH 4 OH solution. Most of the solvent was removed by distillation under reduced pressure at 60-65° C. The crude residue was dissolved in 75 ml water and extracted with 100 ml×2 ethyl acetate. Pooled ethyl acetate layers were concentrated under reduced pressure to get a black oily material and was dissolved in 100 ml methanol, cooled to 0-5° C., and treated with a solution of sodium hypochlorite (15%, 10 ml). After the completion of the reaction, it was processed as in example-1. Yield: 5.3 g, 0.013 mol, (52%). | The present invention provides a method for preparing colorless sucralose, wherein 4,1′,6′-trichloro-4,1′,6′-trideoxy-galactosucrose-6-acetate containing colored impurities formed during chlorination of sucrose-6-acetate is treated with sodium hypochlorite, where sodium hypochlorite acts both as a decolorizing agent and as a reagent for the ester hydrolysis. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an automatic mask (reticle) washing apparatus for the production of semiconductor integrated circuits (IC), and in particular, to cleaning a mask without the use of a strong oxidizing agent or strong alkaline agent.
2. Description of the Prior Art
In semiconductor device manufacturing, it is important to obtain a clean surface mask in order to attain high reliability of devices and high yield of production. There are apparatuses to clean the slices or substrates of semiconductors, but cleaning of the mask is done by hand. The reason the masks have been cleaned manually is that the number of masks used in the process is much smaller than that of the slices. But as the scale of production increases and the complexity of the IC is increased, the number of masks used in the process has become large.
The contamination or damage to the mask is due to the dust, mist, finger masks, spit, etc. In order to remove such contamination, hard washing is not desirable. Moreover, strong oxidizing or alkaline agents are also undesirable because of straining of the mask surface. The cleaning of the mask by hand has not been satisfactory and, therefore, apparatuses for washing and drying of the mask are beginning to be used.
By the experience of the inventor herein, it is insufficient to use prior art apparatuses for washing, drying and so on because during transportation between stages of the apparatus, the mask surface is exposed to the air and thus, contaminated. It is desirable, therefore, to use an apparatus which handles the mask automatically from loading the mask, washing, drying and taking out.
SUMMARY OF THE INVENTION
An object of the present invention, therefore, is to provide a washing apparatus for a mask (reticle) for semiconductor device production which can completely automate the mask loading and washing process for a high quality mask.
Another object of the present invention is to provide a washing apparatus which prevents the contamination of the mask by the atmosphere during the transportation of the mask.
The foregoing objects are attained by providing a specifically designed chamber. The mask is loaded from the top of the chamber and transported to the bottom of the chamber, then brought up gradually to the top of the chamber. During the transit, the mask is washed and scrubbed in a cleanser, rinsed by a pure water jet and dried by a clean air jet.
Further detail and advantage of the present invention will become clear from the accompanying drawings and the detailed description of the preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows schematically a sectional view of a mask washing apparatus of the present invention, illustrating the chamber thereof.
FIG. 2 is a front elevation perspective view of a portion of a mask holder of the present invention.
FIG. 3 shows schematically a prior art means for drying the mask by a jet of gas.
FIG. 4A illustrates a top view of a means for emitting a jet of gas to dry the mask of the present invention.
FIG. 4B is a sectional view along the line A--A of FIG. 4A illustrating the effect of the present invention.
FIG. 5A illustrates schematically gas flow in the chamber when the washing apparatus is in a water washing cycle.
FIG. 5B illustrates schematically gas flow in the chamber when the washing apparatus is in a drying cycle.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows schematically a view of a mask washing apparatus embodying the present invention. The main part of the mask washing apparatus 43 comprises an airtight chamber 5, which includes a mask loading gate 42, a washing space 40 and a drying space 41.
A first automatic shutter 2 is provided on the top of the chamber 5, the shutter 2 being controlled by a gas-cylinder 14. The shutter 2 is opened only when the mask 1 is loaded or unloaded.
The drying space 41 in the airtight chamber 5 is provided with a pair of nozzles 7a and 7b which emit a jet of gases to the mask surfaces. The mask is mounted on a mask transfer mechanim 6, movable up and down in the airtight chamber 5. A pair of air inlets 13 at the side of the airtight chamber 5 are respectively connected through a duct to blowers 23. The air taken into the airtight chamber 5 is filtered by micro air filters 13a and 13b.
The washing space 40, in the airtight chamber 5, is provided with a pair of jet nozzles 8a and 8b and two pairs of scrubbing pads 9a and 9b and 10a and 10b. The nozzles 8a and 8b jet distilled water to clean the mask. Each washing pad is rotated about an axis by motors 18a, 18b, 18c and 18d through transmissions 19. The airtight chamber 5 is provided with means 20a and 20b for supplying the cleanser, a drain 21 and a mask holder 22.
A separation wall 12, between the drying space 41 and the washing space 40, has a second shutter 11 which is controlled by a gas cylinder 15.
A device for exhausting gases is provided on the bottom of the airtight chamber 5, and comprises an exhaust fan 3, an exhaust duct 4 and a drain pipe 21.
The mask 1 is loaded on a mask holder 22, and is moved toward the bottom of the airtight chamber 5 by a mask transfer mechanism 6. When the mask 1 is inserted in the airtight chamber 5, the first shutter 2 is closed and when the mask 1 reaches to the bottom of the airtight chamber 5, the second shutter 11 is closed.
When the mask 1 reaches the bottom of the airtight chamber 5, it is positioned to face the scrubbing pads 10a and 10b in the washing space 40. In this position, both surfaces of the mask are washed with a cleanser. Cleanser is supplied to the scrubbing pads from the cleanser suppliers 20a and 20b, through a pipe which holds the pads. During the time for cleansing and scrubbing by the scrubbing pads 10a and 10b, the mask is gradually lifted up towards the top of the airtight chamber 5, at a speed of 3-4 mm/sec, for example. When the mask reaches the position of the scrubbing pads 9a and 9b, the mask is washed with distilled water. The water is supplied to the pads from the water suppliers 17a and 17b through the pipe which holds the pads. During the time for washing with distilled water and scrubbing by the scrubbing pads 9a and 9b, the mask is gradually lifted as mentioned above. Similarly, when the mask is lifted to the position of a pair of jet nozzles 81 and 8b, the nozzles emit distilled water jets. The jet streams blow off the water sheath covering the surface of the mask while the mask is gradually lifted.
After the washing with distilled water from the jet nozzles, the mask is blown by air to blow of the water drops on the surface of the mask. The air jet blows the mask from its upper side to the bottom of the chamber, this is intended to drop the water to the bottom of the chamber so it does not come up again to contact the mask. This situation will be described below in more detail with reference to FIG. 5. After the washing process is complete, the mask is lifted from the washing space 40 to the drying space 41 through the second shutter 11. The second shutter 11 is usually closed, but is opened by gas cylinder 15, when the mask passes through it.
In the drying space 41, the mask is dried by a pair of air-knife shaped nozzles 7a and 7b which emit a jet of dried nitrogen onto the mask. The knife nozzles will be discussed in more detail below with reference to FIG. 4. During this time, the mask is dried by air from the blowers 23 which have micro air filters 13a and 13b. After the drying of the mask is completed, the mask is taken out of the airtight chamber 5 through the first shutter 2.
FIG. 2 is a front elevation perspective view of a portion of mask holder 22. The mask holder 22 comprises a frame 25 and holder springs 26, which are made of stainless steel. The size of the mask holder corresponds to the size of the mask. The mask 1 is inserted into the mask holder as shown by the arrow A and supported by the holder springs 26.
In the prior art, the mask drying was performed by a spin dryer or by means of natural drying, and sometimes it was performed by replacing the water with alcohol. Therefore, it was difficult to dry the mask speedily, moreover, the mask was contaminated during the drying process. The contamination was further increased when the mask was transported from one apparatus to the next apparatus. Moreover, the washing method of the prior art has some defects.
For example, FIG. 3 shows schematically a prior art means for drying the mask by a jet of gas. This type of nozzle is sometimes called an air-knife nozzle. The nozzle 28 emits a jet of a knife shaped gas flow 29 diagonally onto the mask 1. The V shaped slit 27 provides a thin planar stream. The width of the stream is equal to the width of the mask. The gas flow 29 from this type of nozzle spreads out as illustrated in FIG. 3, and it drags in the surrounding air as shown by broken line arrows 30. The stream of surrounding air catches the surrounding dust and the mask becomes contaminated. The contaminant is not only the dust in the air, but it may also be contamination which has been just removed from the mask. This destroys the cleaning effect of the washing apparatus.
In order to overcome such problems in the drying process of the present invention, the jet nozzle has been especially shaped. Namely, it provides a pair of air-knife nozzles 7a and 7b, which emit a jet of gas onto the mask. FIG. 4A illustrates a top view of the means for emitting a jet of gas by the present invention. FIG. 4B is a sectional view along the line A--A of FIG. 4A illustrating the effect of the invention.
The tips of the nozzle bodies 31a and 31b are inclined to the surface of the mask 1 at an angle θ (for example, 50-60 degrees), and cover plates 32a and 32b are fixed to the inclined surface of the tips. Orifices 33a and 33b have a width W between the nozzle body and cover plate, as shown in FIG. 4A. As a result, air-knives 34 are formed by the orifices 33a and 33b. The gas flow of the air-knives is directed downward along the surface of the mask 1. A gap d between the mask 1 and the cover plates 32a and 32b is set to less than one mm. The nozzle bodies 31a and 31b have cavities 35a and 35b which are connected to the gas pipes 36a and 36b respectively.
As shown in FIG. 4B, micro air filters 13a and 13b are positioned close to the nozzles 36a and 36b to provide dust free air flow 37 toward the mask 1. Moreover, the gas in the airtight chamber 5 is evacuated by a pump (not shown) from the bottom of the chamber. It will be apparent from the illustration that the air flow which is drawn into the knife-shaped air jet is prevented. Therefore, the contamination by drawn in air flow of the prior art is eliminated.
FIG. 5A illustrates schematically gas flow in the chamber when the washing apparatus is in a water washing cycle, and FIG. 5B illustrates schematically gas flow in the chamber when the washing apparatus is in a drying cycle. Reference numerals in the figure designate the same or corresponding parts of the apparatus shown in FIG. 1.
During the washing of the mask 1, as shown in FIG. 5A, the first shutter 2 is closed, the outside air is taken in through the micro air filters 13a and 13b, and the pressure in the drying space is raised, so filtered air stream 39 flows into the washing space 40 through a gap 38 between the separation wall 12 and the side wall of the chamber 5. At the same time, the filtered air flows through the gap 44 between the separation wall 12 and the second shutter 11. The air flow described above prevents the mist of the washing water and the contaminated air from flowing back from the washing space 40 into the drying space 41. The mist and the contaminated air in the washing space 40 are exhausted from the drain and exhaust duct 4. Furthermore, the air flow prevents the mist from adhering to places in drying space 41.
During the drying cycle of the mask 1, as shown in FIG. 5B, the first shutter 2 is closed, but the second shutter 11 is opened. The outside air is introduced through the micro air filter 13a and 13b, so the filtered air stream 39 flows downward into the washing space 40, and a pair of air-knives 34 blow downward onto the mask 1, and the mask is rapidally dried.
Further, since the mask 1 is moving from down to up, and the air-knives 34 are directed from the upper portion to the lower portion of the mask 1, mist from the upper portion is prevented from flowing back towards the upper portion.
As has been described above, by using the automatic mask washing apparatus disclosed herein, it is impossible to clean a mask in the chamber without using a strong oxidizing agent or strong alkaline agent. Further, damage to the mask caused by dust and mist is avoided, and clean surfaces of the mask are obtained. Consequently, the reliability of the mask and the yield of the production are increased.
The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are, therefore, to be embraced therein. | This invention relates to a mask (reticle) washing apparatus for use in the production of semiconductor integrated circuits (IC), and in particular, to cleaning a mask without the use of a strong oxidizing agent or a strong alkaline agent. The mask washing apparatus comprises an airtight chamber including a washing space and a drying space which are separated by a shutter. A drain and an exhaust duct are located at the bottom of the chamber. The washing is performed at a lower part of the chamber and the drying is performed at an upper part of the chamber. A clean air stream flows from the upper part to the lower part of the chamber, and this flow eliminates contamination in the chamber. Consequently, the mask is cleaned perfectly, and the reliability and yield of the device is improved. | 8 |
FIELD OF THE INVENTION
[0001] The present invention relates to a barium titanate solid solution single crystal and a preparation method thereof, and more particularly to a hexagonal phase barium titanate single crystal that can be prepared by adding and dissolving a small quantity of transition metal oxide into barium titanate, and prepared by using a pressureless sintering process at normal atmospheric pressure.
[0002] Since barium titanate polycrystalline ceramic has an excellent ferroelectric property, therefore it is used widely as passive components and communication components. However, the grain boundary often presents in a polycrystalline material, and those single crystals do not have any grain boundary, and thus their properties are the best theoretically. The ferroelectric properties of barium titanate single crystals are better than those of the barium titanate polycrystals. Since there is no grain boundary, the single crystals have a light transmitting capability. With a special refractive nature, the single crystals can be applied in the area of optical communications and thus they have a high potential for both electrical and optical applications.
BACKGROUND OF THE INVENTION
[0003] Barium titanate is a ferroelectric material with high permittivity. The phase of barium titanate at room temperature is a tetragonal phase, it then transforms to cubic phase at 130° C., and then transforms to hexagonal phase above 1460° C. The preparation of tetragonal barium titanate single crystal can attract a lot of attention. However, the preparation of hexagonal phase barium titanate attracted much less attention. Apart from the ferroelectric performance of the barium titanate single crystal, due to the absence of grain boundary in single crystal, the barium titanate single crystal is also a potential material for optical applications. For example, the barium titanate is an excellent photorefractive material having the features of a highly self-pumped phase conjugator and a two-beam coupling effect. Various optical conversional tools can be made by using the barium titanate single crystals, thus the barium titanate single crystals are used widely in many areas, such as in optical information storage, interferometer, optical computation, holographic memory, conjugate optics and many other areas, which indicates that the barium titanate single crystals have excellent industrial prospects. However, the growth of the barium titanate single crystals is very difficult. Although a large number of researchers are devoted to the growth of the barium titanate single crystals, not too many of them have succeeded. As a result, the price of the barium titanate single crystals remains very high (over 300 US dollars for a piece of barium titanate single crystal with a volume of 5×5×5 mm 3 ). Until now, only the tetragonal barium titanate single crystal is available, and the hexagonal barium titanate single crystal is still not available. At present, the conventional methods of growing barium titanate single crystals rely on the expensive instruments, expensive equipments and complicated manufacturing procedures to grow large single crystals. One of the conventional methods, utilizes the melting properties of the materials, such as a top-seeded solution growth (TSSG) method is used for achieving the growth of the liquid-state single crystals, and this method puts a ceramic material into a crucible and heats the ceramic material till it melts, and then puts a small single crystal at the top of the melted ceramic material as a crystal seed, and pulls the small seed crystal by the Czochralski method. The crystal seed is in contact with the surface of the melted ceramic liquid, and the crystal seed is rotated and pulled, such that the crystal seed starts growing into single crystals. But, this method has the shortcomings of requiring an accurate temperature control and complicated production equipments, providing a slow growth rate, and incurring a high manufacturing cost.
[0004] In addition, another conventional method called laser-heated pedestal growth (LHPG) is used for growing the single crystals, and this method has following advantages: The laser light source can narrow the range of heated light beams, and thus only a small portion of the raw material is heated. As a result, the contamination from the crucible can be reduced. Furthermore, the laser light source has a high temperature gradient to induce a quick crystal growth, it also comprises a high power to melt the materials with a high melting point or to grow the non-eutectic materials. However, the high temperature gradient of the laser light source also comes along with some drawbacks, such as easy breaking crystal grains when the diameter increases, and expensive and complicated equipments are required.
[0005] In another conventional method of growing barium titanate single crystals, several elements with high concentration gradient are mixed into a pure barium titanate ceramic green part or it requires a temperature gradient at the sintering process in order to produce the single crystal. Therefore, this method must adopt the two-stages of heat treatment for preparing the crystal seed in order to produce the barium titanate single crystals.
[0006] To summarize the descriptions above, the conventional methods of growing tetragonal phase barium titanate single crystals still have their limitations and disadvantages, and the major drawbacks include the complicated manufacturing process, the expensive instruments and equipments, and the high production cost.
[0007] Therefore, it is an important object of the present invention to find a way of producing the barium titanate single crystals by a simple method to improve the yield rate and to reduce the cost of the barium titanate single crystals. Furthermore, similar to the tetragonal phase, the hexagonal phase is also not a symmetric crystal. The dipoles composing of positive and negative ions are existed. The potential of using hexagonal phase barium titanate single crystal for ferroelectric and optical applications is also high.
SUMMARY OF THE INVENTION
[0008] In view of the shortcomings of the prior art, the inventors of the present invention based on years of experience in the related fields. Many experiments have been conducted, and finally developed a barium titanate single crystal and a growing method to simplify the manufacturing procedure, and to improve the yield rate and to reduce production cost.
[0009] Therefore, it is a primary objective of the present invention to provide a barium titanate single crystal. The barium titanate single crystal is primarily made of a novel barium titanate ceramic material with a small quantity of metal oxides to grow into a form of large barium titanate single crystal. The raw material for the preparation of barium titanate single crystal is composed of pure barium titanate ceramic powder and at least one metal oxide powder distributed uniformly in the ceramic powder.
[0010] The present invention discloses a chemical composition for the preparation of barium titanate single crystal. Apart from the starting barium titanate, a metal oxide is also added. The initial content of the metal oxide varies preferably from 0.01 wt % to 5 wt %, based on the total weight of the barium titanate ceramic powder, and more preferably 0.01 wt % to 2 wt %, and most preferably 0.05 wt % to 0.8 wt %. The metal oxide used as a single crystal growth aid in the present invention is a transition metal oxide, it includes but not being limited to, nickel oxide, iron oxide or their mixtures. The barium titanate ceramic powder is mixed with the solid solution metal oxide and sintered at a high temperature and in a normal atmospheric pressure to produce a large barium titanate single crystal.
[0011] The present invention also discloses a method of preparing the single crystal, particularly a method of preparing a barium titanate single crystal. The method comprises melting of a transition metal salt into an appropriate solvent; mixing the solution into a dielectric ceramic powder to form a slurry, calcining the mixed powder at an appropriate high temperature to prepare a specimen; thermally decomposing the transition metal salt into a transition metal oxide; and resulting a uniform mixing of metal oxide.
[0012] The solvent used for melting the transition metal salt in accordance with the preferred example of the present invention comprises: an alcohol, such as ethanol, methanol and isopropanol. The transition metal salt used in the method of the present invention further comprises but it not limits to, a nickel salt or an iron salt. The foregoing mixed slurry is dried to powder by removing the solvent with an appropriate method, and the dried powder can be used for the later heating and sintering processes. The method of removing the solvent can be a centrifugal drying method, a direct bake-to-dry method or a rotary drying method. The sintering process refers to the process comprising a temperature rise to 1300° C. and a temperature holding of an hour, and a cooling. The sintered powder can be grounded and sieved first to give a powder and then pressed to form a specimen used for a later pressureless sintering process.
[0013] In the pressureless sintering method, a high-temperature heat treatment is carried out at normal atmospheric pressure to produce the specimen, wherein the sintering temperature varies from 1350° C. to 1500° C., and the sintering time from several minutes to several hours. This method can grow a single crystal of the size of 10×5×5 mm 3 or larger.
[0014] The pressureless sintering method can be a one-stage heat treatment or a two-stages heat treatment. For one-stage heat treatment, the sintering process is performed at normal atmospheric pressure, and the sintering conditions comprises a temperature risen to a temperature range of 1350° C. to 1500° C., a constant sintering temperature maintaining for several minutes to several hours, and a cooling process. For a two-stages heat treatment, the sintering process is also performed at a normal atmospheric pressure, and the sintering conditions comprise a temperature risen to a temperature range from 1400° C. to 1500° C., no constant temperature maintaining or a constant temperature maintaining for several minutes, and a cooling process to a temperature range from 1300° C. to 1400° C., a constant temperature maintaining for several minutes to several hours, and a cooling process. In the one-stage or two-stages heat treatment, the high-temperature holding time may vary from 1 minute to 10 hours.
[0015] The objectives, features and advantages of the present invention would become apparent from the following detailed description taken with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The accompanying drawings are included to provide a further understanding of the present invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings,
[0017] FIG. 1 shows two photos of barium titanate in accordance with the first embodiment of the present invention, wherein the barium titanate is made by a one-stage sintering method with (a) a sintering temperature of 1400° C. or (b) a sintering temperature of 1500° C.;
[0018] FIG. 2 shows the X-ray diffraction patterns of the pure and Ni-doped barium titanate specimens after sintering at 1400° C. for 2 hour. The upper figure shows the X-ray diffraction pattern of the barium titanate specimen used in the first embodiment. The lower figure shows the X-ray diffraction pattern of the 0.2 wt % Ni-doped barium titanate specimen in the second embodiment. Very large barium titanate grains are found in the specimen;
[0019] FIG. 3 shows three photos of barium titanate specimens added with a small amount of nickel oxide in accordance with the second embodiment of the present invention, wherein the barium titanate is made by a one-stage sintering method with (a) a nickel oxide content of 0.2 wt %, a sintering temperature of 1400° C. and a temperature holding time of 2 hours, or (b) a nickel oxide content of 0.2 wt %, a sintering temperature of 1500° C. and a temperature holding time of 2 hours, or (c) a nickel oxide content of 0.05 wt %, a sintering temperature of 1385° C., and a temperature holding time of 2 hours;
[0020] FIG. 4 shows the barium titanate single crystals obtained from the specimens shown in FIG. 3 .
[0021] FIG. 5 shows two photos of barium titanate containing 0.35 wt % of iron oxide in accordance with the third preferred embodiment of the present invention, wherein the barium titanate is made by a one-stage sintering method with (a) a sintering temperature of 1410° C. or (b) a sintering temperature of 1500° C.;
[0022] FIG. 6 is a curve showing the temperature profile of a two-stage sintering method in accordance with the fourth preferred embodiment of the present invention;
[0023] FIG. 7 shows a photo of barium titanate containing 0.2 wt % of a nickel oxide in accordance with the fourth preferred embodiment of the present invention, wherein the second-stages sintering temperature is 1400° C.; and
[0024] FIG. 8 shows a photo of barium titanate containing 0.35 wt % of iron oxide and prepared by a two-stages sintering method in accordance with the fourth preferred embodiment of the present invention, wherein the second-stage sintering temperature is 1380° C.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] In order to understand the objective, innovative features and performance of the present invention, four embodiments and their corresponding drawings are used to give detailed description of the present invention.
First Embodiment
[0026] This embodiment is used as the basis for the comparison. According to a embodiment of the present invention, a barium titanate (BaTiO3>99%, manufactured by U.S. Ferro Company) powder and alcohol are put into a PE bottle, and zirconium oxide balls are used as grinding media for grinding the powder and alcohol into a slurry, wherein the particle size of pure barium titanate powder is 1 μm.
[0027] The liquid of the slurry is removed first by drying with a rotary evaporator then putting into an oven to dry at 100° C. for another 24 hours.
[0028] The dried powder are removed from the oven, ground by using mortar and pestle, sieved by using a 150-mesh sieve, and dry pressed at a pressure of 20 MPa to produce a cylindrical disc with a diameter of 1 cm or 1 inch.
[0029] The specimen is put into a high-temperature furnace and sintered in a normal atmospheric pressure, wherein the sintering conditions comprise a temperature heating up with a rate of 3° C./min, a sintering temperature of 1350˜1500° C., a constant temperature maintaining for 2 hours, and a cooling process with a rate of 3° C./min.
[0030] Referring to FIG. 1 for the surface of the pure barium titanate specimen, the crystal grains have the size of tens of micrometers and cannot be grown to mm-scale crystals after going through the high-temperature pressureless sintering process. The X-ray pattern for the barium titanate specimen shown in FIG. 1( a ) is illustrated in FIG. 2 . The specimen was sintered at 1400° C. of 2 hours. Only the tetragonal phase is found.
Second Embodiment
[0031] In this embodiment, we can observe the effect of different proportions of transition metal oxides on the microstructure of the barium titanate. This embodiment adds a nickel oxide, a transition metal oxide, into barium titanate powder through the use of different proportions of nickel nitrate, and carrying out the heat treatment as follows:
[0032] The barium titanate powder (which is the same one adopted in the first embodiment) and nickel nitrate of different proportions are put into a PE bottle containing alcohol and mixed by the ball milling for 4 hours to form a slurry, wherein zirconium oxide balls are used as the grinding media.
[0033] The liquid of the slurry is removed firstly by drying with a rotary evaporator, then it is put into an oven to dry at 100° C. for another 24 hours.
[0034] The dried powder is removed from the oven, ground by using mortar and pestle, sieved by using a 150-mesh sieve, and sintered in an aluminum oxide crucible in normal atmospheric pressure, wherein the calcination conditions include a temperature heating up with a rate of 1° C./min, a constant temperature maintaining at 500° C. for one hour, a cooling process with a rate of 1° C./min, in such that the nickel nitrate in the powder is converted into nickel oxide, and the nickel oxide content after the calcination process is 0.05˜0.8 wt % of the total weight of the powder.
[0035] The dried powder is removed from the furnace and ground with mortar and pestle, sieved by using a 150-mesh sieve, and die pressed at a pressure of 20 MPa to produce a disc specimen with a diameter of 1 inch.
[0036] The specimen is put into a high-temperature furnace and sintered at normal atmospheric pressure, and the sintering conditions comprise a temperature heating up with a rate of 3° C. /min, a constant temperature maintaining at a temperature range of 1350˜1500° C., a constant temperature maintaining for 1 to 2 hours, and a cooling process with a rate of 3° C./min.
[0037] Refer to FIG. 2 , the crystalline phases of the 0.2 wt % nickel oxide doped barium titanate specimen after sintering at 1400° C. for 2 hours are tetragonal and hexagonal. The grains with hexagonal phase tend to form anisotropic shape due to the growth rate of each crystalline plane is not the same. These hexagonal large grains can be seen in FIG. 3 . After removing the large hexagonal grains from the specimens, hexagonal phase single crystal can be obtained. Typical single crystals are shown in FIG. 4 . The present embodiment demonstrates that the hexagonal barium titanate can be obtained at a temperature lower than 1460° C., due to the addition of a transition metal oxide. Furthermore, the presence of the transition metal oxide enhances the grain growth of the barium titanate crystals.
[0038] Referring to FIG. 3( a ) for the specimen containing 0.2 wt % nickel oxide, the large single crystals are formed by sintering a barium titanate specimen containing 0.2 wt % of nickel oxide at a sintering temperature of 1400° C., and the temperature is maintained constantly for 2 hours, and the single crystals can grow to large single crystals with a length equal to or greater than 10 mm. In FIG. 3( b ), the sintering temperature is 1500° C., and the grains can grow to large single crystals with a length equal to or greater than 20 mm as shown in FIG. 3( b ).
[0039] For the sintering conditions comprise of the sintering temperature at 1385° C. and a constant temperature maintaining for 2 hours, and the content of nickel oxide is 0.05 wt %, we can also observe large crystals formed in the barium titanate specimen as shown in FIG. 3( c ).
Third Embodiment
[0040] In this embodiment of the present invention, we can observe the effect of another metal oxide on the microstructure of barium titanate. This metal oxide is also added into the barium titanate powder before the sintering process. This preferred embodiment uses iron oxide as the metal oxide. Iron nitrate with different proportions is added and mixed with the barium titanate powder, and a heat treatment is performed as follows:
[0041] The barium titanate powder (which is the same one adopted in the aforementioned embodiment) and iron nitrate of an appropriate quantity are put into a PE bottle containing alcohol and are mixed by ball milling for 4 hours to form a slurry, wherein zirconium oxide balls are used as the grinding media.
[0042] The liquid of the slurry is removed firstly by drying with a rotary evaporator, then it is put into an oven to dry at 100° C. for another 24 hours for the drying process.
[0043] The dried powder is removed from the oven, ground by using mortar and pestle, sieved by using a 150-mesh sieve, and calcineded in an aluminum oxide crucible at normal atmospheric pressure, wherein the calcination conditions include a temperature heating up with rate of 1° C./min, a constant temperature maintaining at 500° C., and a constant temperature maintaining for an hour, a cooling process with a rate of 1° C./min, such that the iron nitrate in the powder is changed into the iron oxide, and the content of the iron oxide is 0.35 wt % of the total weight of the powder.
[0044] The dried powder is removed, and then grounded by using mortar and pestle, sieved by using a 150-mesh sieve, and die pressed at a pressure of 20 MPa to produce a disc specimen with a diameter of 1 inch.
[0045] The specimen is put into a high-temperature furnace and sintered in normal atmospheric pressure, and the sintering conditions include a temperature heating up with a rate of 3° C./min, a constant temperature maintaining at a temperature range of 1350˜1500° C., a constant temperature maintaining for 2 hours, and a cooling process with a rate of 3° C./min.
[0046] In FIG. 5 , we can observe the surface of the specimens, wherein FIG. 5( a ) shows a specimen sintered at a sintering temperature of 1410° C., and FIG. 5( b ) shows a specimen sintered at a sintering temperature of 1500° C. Obviously, lots of large single crystals are formed in the whole barium titanate specimen.
Fourth Embodiment
[0047] In this preferred embodiment of the present invention, we can observe the effect of the sintering conditions on the microstructure of a transition metal oxide doped barium titanate. The preferred embodiment produces a disc specimen according to the first embodiment, second embodiment and third embodiment of the present invention, wherein a two-stage sintering process is carried out (refer to the temperature-time profile as shown in FIG. 6 ). The specimen is put into a high-temperature furnace and sintered in a normal atmospheric pressure, and the sintering conditions include a temperature heating up with a rate of 3° C./min, no constant temperature maintaining when the temperature risen to a temperature range of 1400-1450° C. These steps constitute the first stage of the sintering process. The specimen is then cooled to a temperature range of 1300˜1400° C. at a cooling rate of 3° C./min, and then the temperature is maintained at the constant temperature for 2 hours, wherein those steps constitute the second stage of the sintering process. Finally, the specimen is cooled at a cooling rate of 3° C./min. From the microstructures of the barium titanate single crystals as shown in FIGS. 7 and 8 , these figures show that the barium titanate single crystals can also be obtained by changing the sintering process from the one-stage heat treatment to the two-stages heat treatment.
[0048] To summarize the descriptions above, the present invention adds a small quantity of transition metal oxides into pure barium titanate ceramic powder, and then produces the barium titanate single crystal by a pressureless sintering process. The method in accordance with the preferred embodiments of the present invention is simple to be performed, and with its advantages, the method of the present invention is useful to industries. The usual price of the barium titanate single crystal is very high. But the barium titanate single crystals can be produced by using the economically competitive pressureless sintering technique in accordance with preferred embodiments of the present invention, and thus the recipe and manufacturing process of the invention is cost competitive. In addition, the barium titanate single crystals offer better ferroelectric property than that of the polycrystalline barium titanate. Without any grain boundary, the single crystals have a light transmitting capability and comes with a photorefractive nature, and thus the barium titanate single crystal can also be applied in the area of optical communications.
[0049] While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures. | The present invention provides a method of producing the barium titanate solid solution single crystals. The crystalline phase of the single crystal is hexagonal. The method of the present invention, a small quantity of metal oxide is added and dissolved into the barium titanate to form a solid solution. The metal oxides are used as single crystal growth aid; and the barium titanate single crystal can be prepared by using a pressureless sintering process composing of one or two stages of heat treatments that require no special expensive equipments, and thus the method can be used for the mass production of the single crystals. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to a hormonal agent or composition for skin treatment, especially seborrhea, Acne vulgaris, androgenically conditioned alopecia and androgenic symptoms of women.
In central Europe the incidence of hormonally conditioned skin diseases, such as acne, seborrhea and hirsutism, is estimated at 35 to 50%. These illnesses appear primarily in young men and women after puberty who are exposed to considerable suffering because of them (H. Hagen, et al, Klinische Erfassumg antiandrogener Effekte von Dienogest {Clinical Determination of antiandrogenic effects of dienogest}, pp. 223-230 in "Dienogest-Praklinik und Klinik eines neuen Gestagens", A. Teichmann, ed, Walter de Gruyter Verlag, Berlin, N.Y., 1995).
The sebaceous gland activity is considerably influenced by hormones. Testosterone and dihydrotestosterones are responsible for the sebocyte proliferation and sebogenesis and provide, as a result, the driving force for sebogenesis. An interaction with androgen receptors, which are localized in human skin (acne areas, such as the face, upper breast portions, the V-shaped region of the back and the outer sides of the upper arms), especially the sebaceous gland and sebaceous gland follicle, is, among other things, a prerequisite for this(R. Choudhry, et al, "Localization of androgen receptors in human skin by immunohistochemistry: implications for the hormonal regulation of hair growth, sebaceous gland and sweat glands", in J. Endocr. 133, pp. 467-475(1992); M. E. Sawaya, "Purification of androgen receptors in human sebocytes and hair", in J. Invest. Dermat. 98, pp. 92-96(1992).
Continuous sebum production increases in acne patients depending on the androgen secretions and the peripheral response of the end organs and reaches its highest value in Acne conglobata.
A hormonal agent or composition which is described in German Patent DE-PS 43 21 957 is used for acne therapy. This hormonal agent is a composition which is taken orally. Because of its systemic action undesirable effects and material accumulation occur in acne patients. Besides the hormonal treatment of acne it is also known to stimulate hair growth. In German Patent Document DE 36 15 396 a combination preparation comprising a hair tonic including cyproteron acetate in hair tonic is used as a combined preparation for treating the scalp skin and for promotion of hair growth.
The action of cyproteron acetate and chlormadinon acetate during therapeutic application is based on a centrally mediated antigonadotropic effect. Because of that an acne therapy and/or treatment of alopecia in humans is not possible with these active ingredients. Furthermore cyproteronic acetate and chlormadinon acetate causes a peripheral competitive androgen receptor blockage in acne of women (Ch. Luderschmidt, "Die Akne der Frau{The Acne of Women}" in Gynakol. Prax., 19, pp. 479-488, 1995).
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a pharmaceutical composition, especially for the treatment of acne, seborrhea or alopecia, in which the systemic effect of the hormonal agent acting as active ingredient is prevented and a direct peripheral effect is produced at the place of occurrence on the skin (seborrhea, acne areas, alopecia, androgenic symptoms of women) and which may be used in both women as well as men.
It is another object of the invention to still further limit and/or to hinder the permeation of the active ingredient through the skin by suitable galenic measures. Because of these measures the penetration of the skin by the active ingredient is promoted instead of hindered. However the permeation by the substances is controlled by the formulation so that the active material is not available or only slightly available systemically in order to avoid or minimize undesirable effects in the organism.
It is an additional object of the invention to provide a manufacturing or production process for the pharmaceutical composition in which the active ingredient is stable and prepared thermodynamically active so that, after it is applied to the skin, it penetrates the skin very rapidly and to a great extent, however slightly or only in a very much reduced extent by the most diverse penetration paths, e.g. transfollicularly, transglandularly and transepidermally. This process should further guarantee that the active ingredient does not come into contact with water, reactive solvents or surfactants or light for a long period of time.
Particularly it is an object of the present invention to include defatting or deoiling substances, like those described in German Patent Document DE 42 29 820, which promote the penetration of hormonal active ingredients in the skin, for a local, but nonsystemically effective, application. The use of defatting or deoiling substances should prevent or hinder the stimulation of the skin to overproduce oil or fat because of oil or fat removal.
The method of applying the pharmaceutical composition topically after it is prepared by the preparative methods according to the invention releases the active ingredient as fast as possible and as completely as possible, promotes its passage into the skin tissue while avoiding absorption and thus introduces no undesirable reciprocal action (interactions) with the biological tissue, as are known, for example, for certain solvents and surfactants.
According to the invention these objects are attained by a method of topical treatment of Acne vulgaris, seborrhea, androgonically conditioned alopecia and androgenic symptoms of women comprising the step of applying locally on the skin a pharmaceutical composition containing the antiandrogenically acting gestogen, dienogest, or a combination of dienogest and an estrogen, especially 17α-estradiol or estriol.
BRIEF DESCRIPTION OF THE DRAWING
The objects, features and advantages of the invention will now be explained in greater detail in the following description of preferred embodiments, with reference to the accompany drawing, in which
FIG. 1 is a bar graph illustration showing the drastic reduction in androstandiol glucuronide concentration in serum occurring after topical treatment using the pharmaceutical composition according to the invention;
FIG. 2 is a graphical illustration of the relationship of serum concentration of dienogest and time when the dienogest is taken orally, intravenously or applied topically;
FIG. 3 is a cross-sectional view through a reaction vessel for production of the pharmaceutical composition according to the invention; and
FIG. 4 is a graphical illustration comparing dienogest concentration-time curves in serum for different preparations according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The dienogest produces an outstanding sebosuppression when it is applied topically. Because of that, as shown in FIG. 1, appended hereinbelow, a drastic reduction of androstandiol glucuronide concentration in serum and a moderate competitive inhibition of androgen receptors occurs. Androstandiol glucuronide is regarded as a marker of the peripheral conversion of testosterone into dihydrotestosterone. It has been shown that dienogest acts at the level of a stronger antiandrogen such as cyproteron acetate in LNcaP cells in vitro. In combination with an estrogen, such as 17α-estradiol or estriol, the suppressive effects of the hormonal agent according to the invention are increased. At the beginning of the topical treatment particularly there is a direct action of the estrogen on sebogenesis to reduce the sebum influence. A definite reduction in sebaceous gland surface area has also been proven. Androgen receptors in the shrunken sebaceous gland may be detected only rarely or not at all. The acne improves after three to four weeks of treatment. The topical application of a combination of dienogest and an estrogen in a suitable galenic form is advantageous with significant acne.
In contrast to the two gestogens, cyproteron acetate and chlormadinon acetate, dienogest in the galenic preparation described in this patent, does not penetrate through the skin and acts directly on end organs. Because of this dienogest, also in combination with an estrogen, has the major advantage that it acts directly on skin end organs in topical application in male and female patients.
Concentration-time experimentally determined curves show that 10 mg of dienogest, delivered transdermally, in contrast to the results or oral and/or i.v. application (2 mg of dienogest), do not penetrate the skin barrier. The concentration-time curves illustrated in FIG. 2, described hereinbelow, clearly show that this is the situation. The dienogest concentration values in serum vary in the vicinity of predetermined limits (1 ng/ml) after transdermal distribution. A systemic effect of dienogest is not expected until its concentration in serum reaches 10 ng/ml.
A systemic action of dienogest is however prevented, since the active ingredient in the proposed galenic formulation does not penetrate the skin barrier and thus can not cause systemic effects. Because of that undesirable systemic side-effects, which, among other things, can occur on oral application, are prevented in this type of topical application. In the galenic preparation(salve, cream, lotion, facial tonic, hair tonic or hair balm) the gestogen, dienogest, is contained or present advantageously in an amount between 0.01 to 4 percent by weight in the preparation.
According to the invention the effective ingredient in the galenic preparation is present in a hydrophilic or deoiling foundation in a thermodynamic state suitable for the preparation. The effective ingredient is thus prepared so that it is distributed molecularly dispersed in the deoiling or hydrophilic foundation. In the case of a hydrophilic preparation (aqueous solution, hydrogel, lotion or O/W emulsion) it is sufficient that the gestogen is dissolved in ethanol or a similar vehicle and added in this form. In the case of the deoiling preparation (lipogel or a preparation containing at least one partly fatty or similar substance, e.g. a W/O emulsion) the active ingredient is combined with a hydrophilic component (H) and generally molecularly dispersed in it. Advantageously sugar or sugar-like substances, such as saccharose, lactose, mannitol, sugar alcohol, urea or other N-containing compounds can be used as the hydrophilic ingredient(H). On contact with skin liquids (e.g. sweat) the hydrophilic ingredient sees to it that the effective ingredient very rapidly goes into solution and penetrates the skin.
It has also proven to be advantageous to mix the solution of the active ingredient with a permeation promotor and/or a stabilizer. The permeation promotor additionally promotes the absorption of the active ingredient in the skin. A nitrogen-containing compound, e.g. an acid amide, an amine or an alkaloid, may be used as permeation promotor. Urea is particularly suitable as permeation promotor.
The stabilizer provides the active ingredient with a sufficient stability, especially in the case of the solution. The antioxidants known from basic principles, such as tocopherol, can be used as the stabilizer, however also complex formers, reducing agents and/or UV-absorbers may also be considered. The permeation of the effective ingredient by the skin is limited and/or hindered by the preparation according to the invention and a comparatively high availability of the active ingredient on the skin is provided. When the preparation according to the invention based on a deoiling foundation is used in addition the stimulation of oil overproduction is countered, since a certain controlled amount of oil required for reconstituting the skin is provided.
For example, oils(e.g. peanut oil and/or castor oil), waxes(e.g. bees wax, hard wax, fluid wax), hydrogels, ethanol, water, benzyl benzoate, isopropyl myristate, lecithin, glycerol, lanolin, boric acid, sodium tetraborate, lactic acid, viscous fluid paraffin, propylene glycol, deionized water or a mixture of these compounds can be used as the carrier/auxiliary substances for the locally applied preparation including dienogest. With the help of this preparation the cutaneous pharmacological action of the antiandrogenically acting gestogen, dienogest, also in combination with an estrogen, the reduction of sebogenesis (estrogen effect) to sufficient extent in the skin is guaranteed. Because of that sebosuppression occurs, which leads to a reduction of sebaceous gland surface and elimination of comedones. A disadvantgeous action of the dienogest is not present because of the gelenic preparation. Damage to the treated skin (horny skin, hair follicules) does not occur.
Allergic and toxic reactions are not to be expected because of the active ingredient, the combination of the active ingredient with estrogen and also the additive and auxiliary materials.
A closed system is suitable for making the pharmaceutical preparation according to the invention. The active ingredient, protected from light, is combined in a predetermined weight ratio with a permeation promotor and a stabilizer in the closed system and is in the same process at most briefly heated and can be dispersed with the aid of a high speed mixer in a lipophilic or hydrophilic vehicle. To make the pharmaceutical preparation according to the invention advantageously the apparatus shown in FIG. 3 is used, which comprises a closed vessel 1 which is equipped with a first stirring apparatus 3, a second stirring apparatus 5, a wiper apparatus 4 and laterally with a heatable or coolable jacket 6. The vessel 1 is provided with an upper filling connector pipe 2 and a lower filling connector pipe 7. Drive devices 8 and 9 are provided for the respective apparatuses 3 and 4.
The method of making the preparation according to the invention is now described for the pharmaceutical preparation with the gestogen, dienogest, as active ingredient. A mixture of conventional additive materials often used in dermatological compositions (see the example) is present in vessel 1. The additive materials are introduced in liquid or solid form through the upper filling connector pipe 2. The first slowly running stirring apparatus 3 is put into rotation by operating the drive device 8. At the same time a wiper apparatus 4 is activated so that a minimum amount of material adheres to the edges of the vessel 1. In a hydrophilic preparation the gestogen, dienogest, is introduced through the lower filling connector pipe 7 as a pure substance or dissolved in a hydrophilic vehicle. A permeation promotor and/or stabilizer is added jointly with the gestogen or after the active ingredient is completely dispersed in the mixture with the additive materials. After that, the entire mixture is homogenized with the help of the comparatively more rapidly running stirring apparatus 5. Depending on the rigidity of the mixture usually brief heating occurs. Usually however at the beginning of the homogenization a cooling must be performed.
The cooling interval is essential for the stabilization of the thermodynamic state of the gestogen in the preparation. The cooling and stirring speeds are decisive for the effectiveness of the gestogen in the resulting preparation with a given recipe and concentrations of homogenizer/stabilizer. Furthermore the stability of the gestogen in the preparation essentially depends on the temperatures existing during the making of the preparation. It has proven particularly advantageous when the temperature in the vessel and similarly the rotation speed of the stirring devices are regulated stepwise and are related in a definite manner to the heating/cooling rate of the jacket surrounding the vessel. Air or liquid (water) can flow through the jacket.
In the method of making the pharmaceutical preparation based on a deoiling foundation the pharmaceutically active ingredient is mixed in a separate vessel with a hydrophilic component or ingredient. This mixture is heated to at least partially melt it while excluding water, other solvents and/or surfactants and subsequently is dispersed with rapid cooling in a gas. The intermediate product arising therefrom is now added to another mixture of auxiliary materials commonly used in dermatological preparations which was prepared in an additional vessel and is dispersed uniformly in the galenic preparation. Either jointly with the active material or after the active material has been completely dispersed, a permeation promotor and/or stabilizer is added. The temperature is increased so that a creamy mixture is guaranteed. Besides a first stirring device with a comparatively lower rotation speed a second stirring device with a comparatively higher rotation speed is used as homogenizer. The temperature of the preparation is now continuously lowered. The cooling rate is advantageously about 1° C./min.
The making of a galenic preparation is possible with the process according to the invention without bringing the active ingredient into contact with reactive solvents or surfactants and without exposing it to light for a substantial time.
Besides gestogens, such as dienogest, additional active ingredients, especially hormones such as natural and/or synthetic antiandrogens(chlormadinon acetate), estrogens and corticoidal steroids, may be applied locally in a galenic preparation based on the above-described process. The pharmaceutical preparation thus made does not produce systemic effects or only produces slight systemic effects. The pharmaceutical preparations according to the invention with dienogest or a combination of dienogest and an estrogen and/or other natural and/or synthetic antiandrogens as active ingredient may be used for local treatment of a plurality of androgen caused maladies or diseases. Hair tonic, hair balm and/or hair cream based on the pharmaceutical preparation according to the invention can be used for treatment of hair loss or promotion of hair growth and as a palliative for and/or for elimination of vasomotor scalp pains. Thus, among other things, it is possible to prevent hair loss in women with androgen symptoms, especially in the post menopause phase, by direct application of the preparation according to the invention to the scalp skin, and/or to promote hair growth.
The invention will now be illustrated with the following examples, whose details should not be construed as limiting the appended claims.
EXAMPLES
______________________________________Example 1: Facial Lotion Solution______________________________________0.25 g dienogest0.40 g castor oil0.60 g benzyl benzoatead 100.0 g ethanol(96%)q.s. dye compound, perfumes100.00 g______________________________________
Preparation:
Dienogest and benzyl benzoate are dissolved in a given amount of ethanol (96%). The mixture is heated briefly to 50° C. After that the mixture must be rapidly cooled to 20° C. Subsequently the required dyes and perfume materials dissolved in the given quantity of castor oil are added to the solution.
______________________________________Example 2: Facial Lotion Solution______________________________________0.25 g dienogest0.40 g peanut oil2.5 g lecithin2.0 g isopropyl myristatead 100.0 g ethanol(96%)q.s. dye compound, perfumes100.00 g______________________________________
Preparation:
Dienogest and isopropyl myristate are dissolved in the given amount of 96% ethanol. Thus the mixture is briefly heated to 50° C. Subsequently it is rapidly cooled to 20° C. Finally the required dyes and aromatic materials which are previously dissolved with lecithin in the peanut oil, are added as a mixture with the oil and lecithin to the solution.
______________________________________Example 3: Skin Cream______________________________________Part A4.5 g Bees wax9.5 g hard wax3.5 g lanolin8.0 g isopropyl myristate8.0 g liquid wax4.0 g glycerol37.5 g total for part APart B2.2 g dienogest4.4 g sacchrose6.6 g total for part BPart C55.6 g deionized water0.2 g sodium tetraborate1.5 g boric acid0.7 g lactic acid62.2 g total for part CPart Dq.s. preservative materials and perfumes.______________________________________
Preparation:
The materials of part A are heated to 90° C., melted and mixed. A solid dispersion (part B) made according to the method already described from dienogest and saccharose 1:2 is homogeneously dispersed in the melt. This is processed in the above-described reactor vessel according to the invention with the following conditions:
______________________________________vessel temperature after adding the solid dispersion: 40° C.rotation speed of the wiper 1 rpmrotation speed of the slower stirrer 50 rpmrotation speed of the homogenizer 3450 rpmcooling rate 1° C./min______________________________________
______________________________________Example 4: Skin Salve______________________________________Part A4.0 g Bees wax9.5 g glycerol monostearate4.0 g lanolin8.0 g isopropyl myristate8.0 g paraffin(viscous liquid)4.0 g propylene glycol37.5 g total for part APart B20.0 g deionized water0.2 g sodium tetraborate20.2 g total for part BPart C0.16 g dienogest19.84 g ethanol20.00 g total for part CPart Dq.s. preservative materials and perfumes.______________________________________
Preparation:
The A portion was heated to 90° C., melted and mixed. The melt is mixed(partially saponified) with the borax solution which was also first heated to 90° C. Subsequently the mixture of parts A and B is cooled to below 50° C., before the ethanolic dienogest solution(part C) is mixed with it. Finally the preservative and perfume containing part D is added to the mixture of parts A, B and C. Then the product is cooled at 20° C. with stirring.
______________________________________Example 5: Skin Lotion______________________________________Part A0.50 kg dienogest9.45 kg ethanol0.05 kg glycerol10.00 kgPart B1.0 kg sorbitan monostearate1.5 kg macrogol stearate2.5 kg medium chain length triglyceride0.05 kg potassium sorbate0.025 kg water-free citric acid waterad 40.00 kg______________________________________
Preparation:
The solution(part A) is homogeneously distributed in the mixture B. The preparation then proceeds according to the general method described hereinabove with the following conditions:
______________________________________Vessel temperature on addition of solution A: 30° C.Rotation speed of the wiper: 1 rpmRotation speed of the slower stirrer: 90 rpmRotation speed of the homogenizer 3850 rpmCooling rate: 1° C.______________________________________
______________________________________Example 6: Lipogel______________________________________5.0 g dienogest1000.0 g wool wax alcohol salve______________________________________
Preparation:
The micronized dienogest is uniformly distributed in the stated amount in the wool wax alcohol salve.
______________________________________Example 7: Lipogel + H with Dienogest______________________________________5.0 g dienogest45.0 g lactose wool wax alcohol salve to1000.0 g______________________________________
Preparation:
A solid dispersion of dienogest and lactose 1:9 is first prepared according to the above-described methods. This solid dispersion is uniformly distributed in the wool wax alcohol salve according to DAB 10. In an analogous smaller vessel, as described earlier in the description above, this is processed under the following conditions:
______________________________________vessel temperature after adding the solid dispersion: 40° C.rotation speed of the wiper 2 rpmrotation speed of the slower stirrer 10 rpmrotation speed of the homogenizer 2050 rpmcooling rate 1° C./min______________________________________
______________________________________Example 8: Hydrogel with Dienogest______________________________________5.0 g dienogest400.0 g ethanol30.0 g methylhydroxyethyl cellulose pure water to1000.0 g______________________________________
Preparation:
The stated amount of dienogest is dissolved in the ethanol and uniformly mixed with the aqueous methylhydroxyethyl cellulose gel as described above.
______________________________________Example 9: Hydrogel with Dienogest and 17α-Estradiol______________________________________5.0 g dienogest5.0 mg 17α-estradiol400.0 g ethanol30.0 g methylhydroxyethyl cellulose pure water to1000.0 g______________________________________
Preparation:
The stated amounts of dienogest and 17α-estradiol are dissolved in ethanol and uniformly mixed with the aqueous methylhydroxyethyl cellulose gel as described above.
______________________________________Example 10: Lipogel: Dienogest plus Estriol______________________________________5.0 g dienogest20.0 mg estriol wool wax alcohol salve to1000.0 g______________________________________
Preparation:
The dienogest and estriol are uniformly mixed in the stated amount in the wool wax alcohol salve.
______________________________________Example 11: Hair Tonic or Hair Spray______________________________________0.2 g dienogest0.4 g castor oil0.6 g benzyl benzoateq.s. Dye compounds, perfumes ethanol 96% ad100.0 g______________________________________
Preparation:
Dienogest and benzylbenzoate or isopropyl myristate are dissolved in the stated amount of ethanol. The mixture is briefly heated at 50° C. After that it is rapidly cooled to 20° C. Finally the required dye compounds and perfumes dissolved in the stated amount of castor oil are added to the resulting solution.
______________________________________Example 12: Hair Tonic or Hair Spray______________________________________0.2 g chlormadinon acetate0.4 g peanut oil2.5 g lecithin0.6 g benzylbenzoateq.s. dye compounds, perfumes ethanol 96% ad100.0 g______________________________________
Preparation:
The chlormadinon acetate and benzylbenzoate are dissolved in the stated amount of ethanol. Then the mixture is briefly heated at 50° C. After that it is rapidly cooled to 20° C. Finally the required dye compounds and perfumes dissolved in the stated amount of peanut oil are added to the resulting solution.
______________________________________Example 13: Dienogest-Hair Balm with Hair-fixingAction (Conditioner)______________________________________Part A2.0 g cetyl lactate2.0 g isopropyl myristate4.0 g glycerol monostearate1.0 g polyethyleneglycol (PEG)-40-stearate2.0 g cetyl stearyl alcohol1.0 g cetyl alcohol12.0 g totalPart B30.0 g aloe vera as colorless gel33.9 g deionized water0.3 g hydroxypropylmethyl cellulose(HPMC)3.4 g Quat's mixture of Quat-22 and Quat-26(2:5)0.3 g lactic acid67.9 g totalPart C0.23 g dienogest19.75 g ethanol19.98 g totalPart Dq.s. Dye compounds, preservatives and perfumes______________________________________
Preparation:
A glutinous mixture is made from the HPMC and water. The ingredients of Part B are added to the glutinous mixture. The resultant mixture is homogenized and after that heated to 80° C.(water bath). Part B is prepared by mixing the above-stated ingredients of it at 80° C.(water bath). Part B is then mixed with the same heating with Part A. The mixture of parts A and B is cooled with stirring at 50° C. The ethanolic solution (Part C) is added with stirring to the mixture of parts A and B cooled below 50° C. The resultant mixture is cooled further. Finally the required dye compounds, preservatives and perfumes are added to the mixture of parts A, B and C. The resultant mixture I then cooled with stirring to 20° C.
______________________________________Example 14: Chlormadinon Acetate Hair Cream(Grooming Cream)______________________________________Part A4.0 g bees wax10.0 g glycerol monostearate3.5 g lanolin8.0 g isopropyl myristate8.0 g viscous paraffin4.0 g propylene glycol37.5 g totalPart B20.0 g deionized water0.2 g sodium tetraborate20.2 g totalPart C0.19 g chlomadinon acetate19.81 g ethanol20.00 g totalPart Dq.s. Dye compounds, preservatives and perfumes______________________________________
Preparation:
The substances of Part A are heated at 90° C., then melted and mixed. The melt is mixed(partially saponified) with the borax solution(Part C) also heated at 90° C. The resultant mixture is subsequently cooled with stirring to under 50° C., before the ethanolic chlormadinon acetate solution (Part C) is added. Finally, the required dye compounds, preservatives and perfumes of Part D are added to the resulting mixture of parts A, B and C and the resulting mixture is cooled at 20° C. with stirring.
______________________________________Example 15: Dienogest Hair Cream______________________________________Part A4.0 g bees wax10.0 g hard wax3.5 g lanolin8.0 g isopropyl myristate8.0 g liquid wax4.0 g glycerol37.5 g totalPart B0.2 g dienogest(micronized)Part C60.0 g deionized water0.2 g sodium tetraborate1.5 g boric acid0.7 g lactic acid62.4 g totalPart Dq.s. Dye compounds, preservatives and perfumes______________________________________
Preparation:
The ingredients of Part A are heated at 90° C., then melted and mixed. The micronized dienogest (Part B), protected from light, is mixed in this melt. The resultant mixture is subsequently cooled with stirring to under 50° C. The water phase C is added with stirring to the cooled mixture of parts A and B. The resulting mixture is cooled further below 50° C. Finally, the required dye compounds, preservatives and perfumes of Part D are added to the resulting mixture of parts A, B and C and the resulting mixture is cooled at 20° C. with stirring.
The purpose of these pharmaceutical preparations, above all, is the penetration of the active ingredient into the skin while limiting or preventing resorption and the penetration of the active ingredient through the skin.
Clinical Tests
To test the performance of the formulae or compositions of the above-described examples, portions of hydrogel (Hydrogel, Example 8) and a Lipogel without (Lipogel, Example 6) and with a hydrophilic additive according to the invention (Lipogel+H., Example 7) were applied to three human test subjects respectively under the following conditions: application amount, 2 g(10 mg dienogest); surface, forehead; and acting time 3 h.
After that the dienogest serum level was determined by means of RIA. As shown in FIG. 4 while a comparatively large amount of dienogest is found in the serum from a pharmaceutically ordinary lipogel, this is not the situation when the hydrogel and the lipogel with hydrophilic additive are used. The serum level of both the latter preparations does not differ significantly from each other. Both serum levels of these preparations differ significantly from the serum level of dienogest resulting from application of the lipogel without the additional additive. That means that with these latter preparations significantly more dienogest remains in the skin and as a result systemic side effects are largely prevented. The serum concentration of dienogest usually required for systemic side effects amounts to 40 to 50 ng/ml. The dienogest serum level after application of the preparation according to the invention amounts to about a factor of 20 lower than this threshold for side effects.
All forms of acne and increased sebum production(seborrhea) are treatable by topical application of the dienogest-containing formulations(facial lotions, skin salves, skin creams, lotions). The sebaceous gland activity has a typical time course in women during aging. Approximately every second women, beginning with the age of puberty, has a more or less remarkably increased sebaceous gland secretion which can lead to oily skin.
In a study of penetration by dienogest of intact skin in 9 human test subjects it was proven that the effective ingredient (hydrogel formulation) did not penetration into the body. No active ingredients were found in the blood plasma of 5 acne patients 12 and 24 hours after being treated twice with the compositions according to the invention (10 mg dienogest in 2 g skin salve).
The effect of a 2.2 g dienogest-containing skin cream (example 2) was tested in acne patients and patients with seborrhea during activity studies in 24 women of ages between 18 and 45 years and 18 men of ages between 24 and 46 years. In all patients the dienogest-containing skin cream was applied to the right half of the forehead. The left half of the forehead acted as control. The skin cream was applied twice daily(morning and evening) to the skin area to be treated. The experiment duration was 8 weeks. In all patients a considerable reduction of the sebum generation was observed already after 8 treatment days. A remarkable reduction of skin surface lipids of about 42 to 47% was observed in both male and female test subjects after 14 to 21 days. Particularly a decline of the wax components was observed. These waxes are of greater significance in the production of acne and comedones. A definite improvement in the acne conditions present in the patients was observed in 4 to 8 weeks of treatment. In 52% of the acne patients after 4 treatment weeks no symptoms remained. After 8 weeks of therapy only 12% of the acne patients had any noticeable acne present and in these cases exceptionally pronounced acne had been present at the start of the treatment. Also in these patients a clearly positive course of the treatment was observed during the eight weeks of treatment.
The dienogest-containing preparations (facial lotion, skin salve, skin cream, lotion) according to the invention are used so that the increased sebaceous gland secretions(seborrhea) and the noninflammed acne are successfully prevented with the help of a sufficient amount of the respective preparations. It is recommended that the topical formulation be used on the skin with various concentrations according to the individual case depending on the strength of the disease being treated. Prior to the beginning of therapy of androgenic conditions skin changes a determined of the individual hormone status is recommended in fertile females.
The treatment with the dienogest-containing skin agent extends to the diseased portions of the skin(seborrhea, acne areas, alopecia, androgenizing symptoms in women). It is recommended that daily applications or applications several times a day be made during treatment of these skin diseases.
Clinical Tests of Acne and Seborrhea Treatments
The tests 1 to 5 hereinbelow exemplify the application of the compositions according to the invention for the treatment of acne and seborrhea.
Test 1
A 0.25% dienogest-containing facial lotion was used for treatment of seborrhea. With increased sebaceous gland production a twice daily application to the affected areas is recommended with increased sebaceous gland production in the facial area. This hormonal agent was used over a period of eight weeks and provided an outstanding sebum suppression.
Test 2
For acne therapy a 3% dienogest-containing skin cream was applied twice daily to the skin areas infected with acne in an acne therapy program. The cream was applied over a 3 month test interval and a very good therapeutic action was observed already after 4 treatment weeks in sever cases of acne.
Test 3
A 0.2% dienogest-containing skin salve was applied at least once per day for treatment of excessive sebum production of the sebaceous gland in the skin. Within a few minutes the salve was absorbed by the skin. The performance observed was similar to the outstanding performance observed during test 1.
Test 4
An 0.5% dienogest-containing lotion was used a preparation for acne therapy. The lotion was applied to the areas having acne twice daily. A very good therapeutic action was observed for this preparation because of the rapid penetration into the skin. The results were similar to those of test 2.
Test 5
An 0.5% dienogest-containing hydrogel which contained 5 mg of 17α-estradiol in 1000 g gel, was applied for treatment of acne. The gel was applied once a day for a 3 month test period. Already after 4 treatment weeks a definite sebosuppression effect was observed with partial eliminated of comedones.
The following tests 6 to 8 shows the application of the compositions according to the invention for the treatment of hair loss and the promotion of hair waxes.
Test 6
For treatment of the entire scalp skin use of a 0.2% hair tonic/hair spray is recommended, in which a total dose of 20 ml per week should not be exceeded.
Test 7
A 0.5% hair tonic/spray is recommended for treatment of postmenopausal androgenically conditioned hair loss at a maximum dosage up to 20 ml per week.
Test 8
For a locally limited androgenically conditioned hair loss only the scalp region (peaks areas, forehead surfaces, rear scalp surfaces)involved should be treated with balm and/or hair cream or hair spray daily or at least 3 times in one week.
A successful therapeutic result in the form of increased hair growth was observed in tests 6 to 8 after 3 treatment months.
The invention described and claimed herein is also described in German Patent Application 195 34 209.7-41 filed in Germany on Sep. 16, 1995. Priority rights based on the aforesaid German Patent Application are being claimed. The disclosure in the priority document, German Patent Application 195 34 209.7-41, is incorporated in this specification by reference.
While the invention has been illustrated and described as embodied in a pharmaceutical composition including a hormonal agent and method for skin treatment, especially of seborrhea, acne and the like, and a method of making the pharmaceutical composition, it is not intended to be limited to the details shown, since various modifications and changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. | The pharmaceutical composition, especially for treating skin with seborrhea, Acne vulgaris and androgonically conditioned alopecia, contains a hormonal agent including the gestogen, dienogest, or a combination of dienogest and an estrogen, as active ingredient. Methods for treatment of this type of skin condition include topical application of the composition including the dienogest which results in an outstanding sebosuppression, a drastic reduction of androstandiol glucuronide and a moderate competitive blockage of androgen receptor sites. Galenic formulations are described which limit and/or prevent the permeation of the active ingredient through the skin. The pharmaceutical preparation including the dienogest and conventional dermatologically acceptable carrier and auxiliary substances in the described galenic formulation advantageously provides a drastic reduction in androstandiol glucuronide and moderate androgen receptor blockage without passing through the skin barrier so that systemic effects including side reactions are substantially prevented. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a division of application Ser. No. 489,449 filed July 17, 1974 now U.S. Pat. No. 3,984,518, itself a continuation of application Ser. No. 126,498 filed Mar. 22, 1971 (now abandoned).
BACKGROUND OF THE INVENTION
1. Field of Invention
This application relates to improvements in feed and effluent treatment particularly but not exclusively adapted to use in dual temperature exchange systems utilizing an external water source as one of the process fluids and a partially water soluble gas as another process fluid.
2. Description of the Prior Art
In my prior U.S. Pat. Nos. 2,895,803 issued July 21, 1959 and 3,142,540 issued July 28, 1964 are disclosed a regenerative stripper system for stripping gas (e.g. H 2 S) from a liquid (e.g. water) with the aid of steam supplied at temperature considerably higher than the temperature at which the liquid became saturated with the gas, followed by a partial recovery of the heat by indirect contact heat exchange with a cold process fluid.
SUMMARY OF THE INVENTION
Objects of the invention are to provide an improved feed and effluent treatment system adapted for improving the recovery of a gas (e.g H 2 S) from solution in a liquid (e.g. water) which liquid also contains dissolved nonvolatile components (e.g. the nonvolatile solutes contents of sea water and other contaminated waters), at low temperatures, and with greater effectiveness than said prior art systems; for conditioning the liquid feed supply for such systems in a simple and effective way; and for producing a distilled liquid by-product essentially free of the solubles of the feed.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings
FIG. 1 is a simplified flow diagram of an integrated feed and effluent system for a hydrogen sulfide-water process, according to an embodiment of the invention in which a contaminated water (e.g. sea water) is the feed supply.
FIG. 2 is a schematic diagram of another embodiment.
DESCRIPTION OF PREFERRED EMBODIMENTS
The embodiments shown in the drawings are particularly adapted for supplying treated liquid feed to, and treating liquid effluent from, a system processing such liquid and a gas partially soluble therein, such as is disclosed in my concurrently filed application Ser. No. 126,692, (now U.S. Pat. No. 3,860,698 issued Jan. 14, 1975) which is made a part hereof by reference.
By use of these embodiments, applied in the production of heavy water, advantage may be taken of the fact that sea water contains approximately 5% more deuterium content than do river and lake waters.
Referring to FIG. 1 of the accompanying drawings:
The feed water (e.g. sea-water) treating system is integrated in operation with the treatment of the impoverished sea-water discharged from the hot tower for disposal to waste, and provides the heated, H 2 S saturated sea-water for deuterium extraction in the dual temperature exchange system. In the illustrated embodiment, the feedwater has initially been utilized for cooling of process fluids in the dual temperature exchange system and is received slightly heated via 3A for treatment.
The feedwater then passes via 4A through a rubberlined carbon-steel hydroclone cleaner F-001 where solids are removed in the underflow and discharged as waste. The cleaned feedwater then enters an epoxy-lined carbon-steel feed deaerator T-001 where dissolved oxygen and carbon dioxide gases are removed. Gases are withdrawn by the two stage action of two ejectors J-003 and J-004 and a barometric intercondenser E-001. Water from the bottom of the condenser discharges to a hot well.
Oxygen is removed to prevent corrosion of metal surfaces and to prevent sulfur precipitation when the water comes into contact with H 2 S used in the process, e.g. by the reaction 2H 2 S + O 2 = 2H 2 O + 2S. Insoluble sulfur precipitates can clog the process equipment. Carbon dioxide is removed to prevent the dilution of the H 2 S process gas, and also to prevent accelerated corrosion of the equipment as a consequence of the carbonic acid found in aqueous solution thereby. The productivity of the dual temperature system is reduced in proportion to the accumulation of inert or non-exchanging contaminants in the process gas. The cooling water via 19A for the barometric intercondenser E-001 is split from the sea-water flow received via 3A: motive steam for the ejectors is taken off the intermediate pressure steam holder.
A pump P-001 withdraws feedwater from the bottom of the deaerator via 77A and passes it to the tube side of the feedwater heat exchangers E-107-. A connection is provided in the passage to the exchangers for chemical addition, e.g. sulfuric acid injection. By this means suitable chemical agents or acid may be added to dissolve scale, e.g. precipitated sulfates or carbonates, if such should form on the heat exchanger tubes from the heating of the sea-water.
In the illustrated embodiment the E-107- heat exchangers are series connected in three parallel trains of four exchangers each. Hot sea-water effluent from the hot tower of the dual temperature system via 8A, after removal of dissolved hydrogen sulfide gas, is passed via 87A, 88A through the shell side of said exchangers whereby the feedwater in the tube side is heated to approximately 250° F. A thermocompressor J-001 supplies steam, which in part has been recovered via 89A from the sea-water effluent by flash evaporator D-006, via 94A, to an injector J-002 for further feedwater heating. The steam is injected into the feedwater at a rate controlled so as to maintain a feedwater temperature of 266° F.
A pump P-002 passes the heated sea-water feedwater stream to the top of the feedwater saturator T-002. The saturator is an Inconel-clad steel tower, designed to saturate approximately 2,000,000 pounds of heated feedwater per hour with H 2 S at 325 psia. An additional stream of heated sea-water that has been used in the upper cooling sections of the waste stripper P-004 and waste flasher P-005 for gas cooling, hereinafter described, it also discharged into the top of the saturator T-002. These streams merge and flow downward against a countercurrent flow of H 2 S gas, becoming saturated, and constitute the sea-water feed supply to the feed section of the hot tower of the dual temperature system.
The H 2 S saturated feedwater is discharged from the bottom of the saturator via 6A and is pumped by the pumps P-003 to Inconel hydroclone cleaners F-003- for removal of heavy metal sulfides and other solids formed by reaction of dissolved minerals in the sea-water under the conditions existing in the saturator. The underflow from these hydroclone cleaners passes via 101A to a sludge tank D-010 for treatment before being removed, e.g. discharged into the effluent stream via 109A. Such treatment may include chemical addition, for example of an acid which reacts with the solids to solublize them and to form H 2 S gas for return to the dual temperature process gas system via 108A-7A. The saturated sea-water feedwater passes via 55A from the hydroclones to the top of the feed section of the stage 1 hot towers.
The H 2 S delivered via 5A to the saturator T-002 is bled as a surge stream from the humidification section of the dual temperature stage 1 hot towers. Within the saturator, the H 2 S reacts with and decomposes dissolved bicarbonate salts, releasing carbondioxide gas (CO 2 ) and forming the hydrosulfide (HS-- ion) and to a small degree the sulfide (S═ ion) salts in substitution. The CO 2 together with other undissolved gases, e.g. nitrogen and hydrogen, are passed through the purge tower section at the top of the saturator. A small stream of relatively pure water, e.g. condensate, is introduced via 60A into the top of the purge tower section to absorb H 2 S contained therein and this water flows downward through the purge section and then merges with the feedwater stream in the saturator. The remaining gas stream, which comprises substantially all of the CO 2 and inert gas content of the fluids delivered to the saturator T-002, is removed via 96A from the system, e.g. to a flare for discharge to the atmosphere.
Cooling water for the gas cooling sections on top of the waste stripper T-004 and on top of the waste flasher T-005 is taken off via 1A from the sea-water supply line serving the dual temperature system stage 1 dehumidifier process liquid coolers. This water is passed through a hydroclone cleaner F-002 for removal of solids and the underflow is discharged to waste. The cleaned water passes to a deaerator T-009.
Chemical addition, e.g. of sulfuric acid, may be added to this sea-water through a connection upstream of the deaerator. Acid is added to decompose dissolved bicarbonate salts and evolve CO 2 before this water enters the waste flasher T-005 and waste stripper T-004, where it comes in contact with H 2 S. The acid-generated CO 2 and other dissolved gases are removed from the water in the deaerator T-009 by the 3-stage action of three ejectors J-005, J-006 and J-007 and two barometric condensers E-002 and E-003, and the deaerated water is then withdrawn by pump P-019 via 98A and is passed via 61A to the waste stripper T-004 and via 62A to the waste flasher T-005.
The effluent stream leaving via 100A is comprised principally of deuterium-depleted sea-water from the dual temperature stage 1 hot towers together with the treated underflow from hydroclone cleaners as above described.
A principle purpose of the effluent treating system is to recover the H 2 S which is present at a concentration of about two percent in the sea-water effluent from the dual temperature system. Another is to recover heat from the effluent which is at 266° F. when it leaves the stage 1 hot towers. The H 2 S is recovered in the waste flashers T-008 to T-005 and the waste stripper T-004 and returned via 7A to the dual temperature system. Heat is recovered in the flash evaporator D-006 where the sea-water effluent after removal of H 2 S is partially flashed to steam for use in part via 90A in the waste stripper and in part via 94A to heat the incoming sea-water feed supply, and also in a series of heat exchangers E-107- where the remaining heat of the sea-water effluent before its discharge to waste is used to heat the incoming sea-water feed to the dual temperature system.
H 2 S is recovered by passing the hot sea-water effluent discharged from the feed section of the stage 1 hot tower through a series of four waste flashers T-008, T-007, T-006 and T-005 in that order. These are horizontal pressure vessels made of Inconel-clad steel plate and consist of a flashing section and a gas cooling tower section wherein the released hot H 2 S is cooled by countercurrent direct contact with a flow of cool water. As illustrated, three of the waste flashers T-008, T-007, and T-006 have integrally mounted contactor cooling towers. One, T-005, operates in conjunction with a separately mounted contactor tower as is shown by the seal tray at 76A which only allows gas to pass therethrough. The waste flashers operate at successively lower pressures, e.g. 305, 250, 175 and 75 psi, respectively. At each stage of pressure reduction, H 2 S is evolved from the effluent. The flashed-off H 2 S flows upward to the gas cooler sections where water vapor is condensed and the H 2 S is cooled. The flashed H 2 S gas is then repressurized, e.g. by compression with gas compressors C-002, C-003 and C-004 to 305 psi, and returned via 7A to compressors C-101-1 & 2 of the dual temperature stage 1 gas system shown in FIGS. 9 (alt), Parts (A) and (B), of the aforesaid U.S. Pat. No. 3,860,698. The gas from waste flasher T-008 is discharged therefrom at the 305 psi pressure of the top of the stage 1 cold tower and therefore does not require further pressure.
After passing through the waste flashers, the sea water effluent is passed to the waste stripper T-004 where the remaining dissolved H 2 S is removed in part by a flash to 35 psi and the remainder by action of a countercurrent flow of stripping steam. This waste stripper is an Inconel tower approximately 85 feet high. It consists of an upper cooling section separated as in T-005 and a lower flashing and stripping section. The H 2 S is evolved from the effluent in the flashing sectaste sripper T-004 passes to a flash evaporator D-006 where a part of the water is flashed and evaporated to steam. The flash evaporator is a copper-nickel-alloy vessel approximately 6 feet in diameter and approximately 13 feet long. It operates in conjunction with a thermo compressor J-001 to recover some of the energy present in the effluent. The thermo compressor creates a reduced pressure in the evaporator vessel, converting a portion of the effluent to steam, which is exhausted via 91A for use as stripping steam via 90A to the waste stripper and for injection via 94A to the main sea-water feed stream to the dual temperature system. The hot effluent from the flash evaporator via 88A is pumped by pump P-017 through the shell side of the heat exchanger train E-107- to heat the main sea-water feedwater stream on the tube side therein. This cooled effluent is then discharged via 100A as waste.
The underflow from the sea-water feed hydroclones F-003- is discharged via 101A to a sludge tank D-010 where sulfuric acid is added. The sludge tank is an Inconel pressure vessel. H 2 S is evolved in the tank from the reaction of acid with sulfides removed in the hydroclone cleaners.
As shown, the evolved H 2 S vapor is passed to the gas cooler tower on the top of the waste flasher T-007 to join the flow of recovered gas to be returned to the dual temperature stage 1, and the discharge from the sludge tank via 109A is mixed with the effluent passing from waste flasher T-008 via 84A. Any excess acid which may be present in the sludge tank discharge continues to react with dissolved sulfides in the sea-water effluent to further evolve H 2 S gas which is chemically or otherwise bound and would not otherwise be released in the flashing and stripping operations.
The evolved H 2 S gas passes from the waste flashers and the waste stripper to the waste flasher compressors. In the illustrated embodiment, the compressors C-001, C-002, C-003 and C-004 may be driven by a single stream turbine through a common shaft, which together comprises a multi-stage compressor unit for compression of the released H 2 S for return to the dual temperature system.
Referring now to FIG. 2 of the accompanying drawings:
In this embodiment the cold sea water feed (e.g. at 20° C.) is passed through an indirect contact heat exchanger 10 in countercurrent to the treated effluent passing to waste, becoming heated (e.g. to 120° C.) while the effluent is cooled (e.g. from 135° C. to 45° C.). The heated sea water via 11 passes to a two stage H 2 S saturator and inert gas and dissolved CO 2 remover 12, 13 wherein a countercurrent contact with a stream of H 2 S the water becomes saturated therewith first at a lower pressure and then at a higher pressure, and the dissolved carbonates therein are converted to hydrosulfides and sulfides, freeing CO 2 water feed which is vented together with any inert gas content of the H 2 S and/or water streams. In the first stage 12 the water feed is heated at a low pressure (e.g. 25 psig) approaching the temperature of the H 2 S gas stream (about 130° C.) depending on the quantity of hot gas delivered. In the second stage 13 to which the treated water from the first stage is pumped via 15 the pressure is higher (e.g. 300 psig) and the saturation with the gas at this pressure is accomplished therein. For mineral removal or recovery, etc. the liquid (e.g. sea water) may be treated with additives supplied as via 16 for precipitating dissolved materials which can then be removed as by a filter, decanter or other separator 17, from which the treated liquid saturated with gas at the temperature and pressure of the process feed section 18 (shown as a feed section comprising the lower quarter of the trays section of the hot tower 18, 19 of a dual temperature exchange unit 18, 19-19b is delivered via 17a to said feed water section 18, as shown 19 is delivered to said feed water section, as shown.
In this feed section 18 the saturated liquid passes in countercurrent exchange with a circulating stream of gas (H 2 S) which has been passed from 5 through the heater and humidifier 20f where it is heated and humidified and brought to the temperature of the feed section 18. The gas heating in the form shown is accomplished in part by direct contact with a branched circulation of water entering via 20a and exiting at different temperature levels (e.g. 85° and 45° C) via 20b and 20c, augmented by injection of steam via 20e 20d (e.g. at 218° C) into 20f sufficient to raise it to the temperature of the feed section 18 and tower 19, (e.g. 130° C). The feed fluid stream leaving the feed section 18 above the seal tray 18a (which allows gas to pass upwardly therethrough but prevents downward flow of feed liquid therethrough) is pumped via 22 to the waste stripper 25 operating at a slightly higher pressure to allow stripped gas (H 2 S) and steam to return via 25e 20d to the top of the heater and humidifier section 20 12f. Steam is supplied via 25a to the bottom of the stripper 25 passing countercurrent to the H 2 S saturated liquid from 22, whereby the water leaving 25 via 25b is substantially free of gas (e.g. H 2 S). Additional steam as needed is supplied to 20d by 20e from a suitable source such as the boiler 30.
In the form shown a portion of the water stripped of H 2 S is passed from 25b via 25c as feed to the boiler 30 wherein it is partially evaporated by an external heat supply. The unevaporated portion via 30a, and liquid via 25d may be merged, and be used in part to heat at least a portion of the cyclic flows via 20c and/or 20b in a heat exchanger 35, and may in part be sent to a flasher 40 operating at reduced pressure where steam is evolved which may be used in stripper 41 to strip H 2 S from a separate flow of H 2 S saturated condensate from 41a formed in the dehumidifier 19a by the cooling and dehumidification of the hot process gas from 9 passing from hot tower 19 to cold tower 19b of said dual temperature exchange unit 18, 19-19b (e.g. as shown in applicant's aforesaid U.S. patent application Ser. No. 126,692), which is about equal to the quantity of steam introduced at 20d. Said condensate, which is supplied via 41a from the Process Condensate Return element 21 paralleling 18, enters 41 via 41a at about 130° C. exits via 41b at about 132° C. and then passes in countercurrent heat exchange in 50 to heat another portion of said cyclic flows 20b and/or 20c. The remaining liquid from 40 and the cooled liquid from 35 via 10a is passed through the heat exchanger 10, as above described. The cooling and dehumdification in 19a is effected by maintaining circulations of the water condensate (constituting the liquid phase in all the contact sections of the system except the feed section 18) through cooling means for cooling the dehumidification setion 19a. The first circulation is the dual temperature process circulation which is cooled, e.g. from 130° to 30° C., by coolers 66 and 67 and passes via 61 and cold tower 19b to the dehumidification section 19a. The second circulation is the local cooling circulation from 19a via 63, cooler 65 and via 64 returning to the cooling and dehumidifying setion 19a.
While there have been described herein what are at present considered preferred embodiments of the invention, it will be obvious to those skilled in the art that modifications, including changes and omissions and substitutions, may be made without departing from the essence and principle of the invention. It is therefore to be understood that the exemplary embodiments are illustrative and not restrictive of the invention, the scope of which is defined in the appended claims, and that all modifications that come within the meaning and range of equivalency of the claims are intended to be described and included therein. | A liquid feed and effluent system to recover dissolved process gas (e.g. H 2 S) from an effluent process liquid (e.g. water), which liquid may also contain dissolved solid components (e.g. soluble salts); the system heats the feed liquid with heat recovered from the effluent liquid, saturates the so heated feed liquid with process gas, which gas may also contain inert gas components, and separately discharges from the system such inert gas components and effluent liquid from which process gas and heat have been recovered. In the combination the dissolved process gas is preferably recovered from the effluent liquid by flashing at progressively reduced pressures and final vapor stripping thereof at the most reduced pressure. | 1 |
This is a Divisional, of the application Ser. No. 09/922,331, filed Aug. 3, 2001, now abandoned.
FIELD OF THE INVENTION
The invention herein described, includes alloys which are resistant to metal dusting.
BACKGROUND OF THE INVENTION
High temperature alloys which are Fe, Ni, or Co based are prone to a virulent form of corrosion known as metal dusting when subjected to environments which are supersaturated with carbon. The problem is generally encountered at temperatures ranging from 300-850° C. Many processes of interest to the petrochemical industry which involve carbon-supersaturated environments, are limited by the lack of available reactor materials and heat exchanger materials that are resistant to metal dusting. Research has led to some understanding of the underlying mechanisms. For the Fe-based systems, the mechanism involves the initial formation of a metastable Fe 3 C carbide on the alloy surface in the carbon-supersaturated environments. Subsequently, graphite deposits on the metastable carbide whereby it is destabilized and decomposes to iron particles and carbon, thus triggering the corrosion process. For Ni based and Co based systems, while no metastable surface carbide forms, graphite deposition on the metal provides channels through which the metal can migrate out. In addition, carbon also supersaturates the metal and causes profuse graphite precipitation in the interior, thus leading to a breaking up of the bulk metal.
The carbon-supersaturated environment that is encountered in process streams consists of either hydrocarbon molecules or carbon monoxide. Of these, the latter is a more virulent metal dusting molecule. Heyse and coworkers have proposed carburization and metal dusting resistant coating systems that are applicable to hydroalkylation processes where hydrocarbon is the main corrosive medium. The general approach to control metal dusting is the use of alloys that can form protective surface oxide films in the environment involved. But in most currently available alloy systems, the break up of the protective surface oxide film leads to local metal dusting corrosion.
Current approaches to control metal dusting involve the use of H 2 S as a gas phase corrosion inhibitor, expensive high temperature alloys and tin based coatings for selected applications involving hydrocarbon corrosives (See for example, Heyse, et.al. U.S. Pat. No. 5,863,418). However, even the more expensive alloys are not fully metal dusting resistant. Coating systems, especially based on tin, have limited applications in predominantly hydrocarbon environments. The use of H 2 S necessitates clean up of the downstream process gas. Further, in many catalytic processes, H 2 S can be a catalyst poison. Thus, its use is rather limited.
Certain coating materials have been taught in the prior art. For example, see U.S. Pat. No. 5,575,902 which teaches the use of Group VIB metals, specifically chromium for coating surfaces susceptible to carburization.
What is needed in the art are materials that are highly resistant to metal dusting corrosion in petrochemical processes where supersaturated carbon environments are present.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 depicts the metal dusting rate (mpy) of Fe-1.25 Cr-0.5 Mo alloy as a function of CO—H 2 gas mixture at 538° C. (1000° F.). The hollow circles are the local rate and the solid circles are the general rate.
FIG. 2 depicts the mass gain due to carbon deposition (a measure of metal dusting corrosion) of Cu-xSn alloys as a function of Sn content at 500° C. in 50 CO:50 H 2 gas mixture after 65 hours of corrosion.
FIG. 3 depicts the concentration profile of Sn in Cu-5Sn alloy as a function of distance from the surface after corrosion in 50 CO:50 H 2 gas mixture at 500° C. after 65 hours.
FIG. 4 depicts the concentration profile of Sn in Cu-8Sn alloy as a function of distance from the surface after corrosion in 50 CO:50 H 2 gas mixture
(a) at 650° C. for 160 hours
(b) at 500° C. for 66 hours
(c) at 400° C. for 94 hours
FIG. 5 depicts the mass gain due to carbon deposition of Cu-xGa alloy as a function of Ga content at 500° C. in 50 CO:50 H 2 gas mixture after 65 hours of corrosion.
FIG. 6 depicts the concentration profile of Ga in Cu-5Ga, Cu-2Ga, and Cu-1 Ga alloys as a function of distance from the surface after corrosion in 50 CO:50 H 2 gas mixture at 500° C. after 65 hours.
FIG. 7 depicts the mass gain due to carbon deposition of Cu-xAl alloy as a function of Al content at 500° C. in 50 CO:50 H 2 gas mixture after 65 hour of corrosion at 500° C.
SUMMARY OF THE INVENTION
An aspect of the invention comprises a composition resistant to metal dusting when exposed to a carbon super-saturated environment at temperatures up to about 650° C. comprising an alloy selected from the group consisting of copper-tin alloys, copper-gallium alloys copper-aluminum alloys, and mixtures thereof, wherein when said alloy is a copper-tin alloy, the amount of tin will range from about 0.1 to about 2 wt % when exposed to carbon supersaturated environments at temperatures of about 500 to about 650° C., about 0.1 to about 5 wt % when exposed to carbon supersaturated environments at temperatures of about 400 to about 500° C., and about 0.1 to about 8 wt % when exposed to carbon supersaturated environments at temperatures up to about 400° C., and wherein when said alloy is a copper-gallium alloy, the amount of gallium will range from about 0.1 to about 2 wt % when exposed to carbon supersaturated environments at temperatures of about 500 up to about 650° C., and from about 0.1 to about 5 wt % for temperatures up to about 500° C., and wherein when said alloy is an copper-aluminum alloy, the amount of aluminum will range from about 0.1 to about 4 wt % when exposed to carbon supersaturated environments at temperatures of about 500 to about 650° C., about 0.1 to about 8 wt % when exposed to carbon supersaturated environments at temperatures up to about 500° C. and wherein when said mixture is a copper-tin-gallium alloy, the amount of tin and gallium combined will be about 0.1 to about 5 wt % when exposed to carbon supersaturated environments at temperatures up to about 500° C. and about 0.1 to about 2 wt % when exposed to carbon supersaturated environments at temperatures of about 500 to about 650° C. and wherein when said mixture is a copper-tin-aluminum alloy, the amount of aluminum will be about 0.1 to about 8 wt % and the amount of tin will be about 0.1 to about 5 wt % when exposed to carbon supersaturated environments at temperatures up to about 500° C. and the amount of aluminum will be about 0.1 to about 4 wt % and the amount of tin will be about 0.1 to about 2 wt % when exposed to carbon supersaturated environments at temperatures of about 500 to about 650° C. and wherein when said mixture is a copper-gallium-aluminum alloy the amount of gallium will be about 0.1 to about 5 wt % and the amount of aluminum will be about 0.1 to about 8 wt % when exposed to carbon supersaturated environments at temperatures up to about 500° C. and the amount of gallium will be about 0.1 to about 2 wt % and the amount of aluminum will be about 0.1 to about 4 wt % when exposed to carbon supersaturated environments at temperatures of about 500 to about 650° C., and wherein when said mixture is a copper-tin-gallium-aluminum alloy, said alloy will contain about 0.1 to about 5 wt % of gallium and tin combined and about 0.1 to about 8 wt % aluminum when exposed to carbon supersaturated environments at temperatures up to about 500° C. and about 0.1 to about 2 wt % of gallium and tin combined and about 0.1 to about 4 wt % aluminum when exposed to carbon supersaturated environments of between about 500 and about 650° C.
Another aspect of the invention is directed to a method for inhibiting metal dusting of surfaces exposed to supersaturated carbon environments comprising constructing said surfaces of, or coating said surfaces with an alloy selected from the group consisting of copper-tin alloys, copper-gallium alloys copper-aluminum alloys, and mixtures thereof, wherein when said alloy is a copper-tin alloy, the amount of tin will range from about 0.1 to about 2 wt % when exposed to carbon supersaturated environments at temperatures of about 500 to about 650° C., about 0.1 to about 5 wt % when exposed to carbon supersaturated environments at temperatures of about 400 to about 500° C., and about 0.1 to about 8 wt % when exposed to carbon supersaturated environments at temperatures up to about 400° C., and wherein when said alloy is a copper-gallium alloy, the amount of gallium will range from about 0.1 to about 2 wt % when exposed to carbon supersaturated environments at temperatures of about 500 up to about 650° C., and from about 0.1 to about 5 wt % for temperatures up to about 500° C., and wherein when said alloy is an copper-aluminum alloy, the amount of aluminum will range from about 0.1 to about 4 wt % when exposed to carbon supersaturated environments at temperatures of about 500 to about 650° C., about 0.1 to about 8 wt % when exposed to carbon supersaturated environments at temperatures up to about 500° C. and wherein when said mixture is a copper-tin-gallium alloy, the amount of tin and gallium combined will be about 0.1 to about 5 wt % when exposed to carbon supersaturated environments at temperatures up to about 500° C. and about 0.1 to about 2 wt % when exposed to carbon supersaturated environments at temperatures of about 500 to about 650° C. and wherein when said mixture is a copper-tin-aluminum alloy, the amount of aluminum will be about 0.1 to about 8 wt % and the amount of tin will be about 0.1 to about 5 wt % when exposed to carbon supersaturated environments at temperatures up to about 500° C. and the amount of aluminum will be about 0.1 to about 4 wt % and the amount of tin will be about 0.1 to about 2 wt % when exposed to carbon supersaturated environments at temperatures of about 500 to about 650° C. and wherein when said mixture is a copper-gallium-aluminum alloy the amount of gallium will be about 0.1 to about 5 wt % and the amount of aluminum will be about 0.1 to about 8 wt % when exposed to carbon supersaturated environments at temperatures up to about 500° C. and the amount of gallium will be about 0.1 to about 2 wt % and the amount of aluminum will be about 0.1 to about 4 wt % when exposed to carbon supersaturated environments at temperatures of about 500 to about 650° C., and wherein when said mixture is a copper-tin-gallium-aluminum alloy, said alloy will contain about 0.1 to about 5 wt % of gallium and tin combined and about 0.1 to about 8 wt % aluminum when exposed to carbon supersaturated environments at temperatures up to about 500° C. and about 0.1 to about 2 wt % of gallium and tin combined and about 0.1 to about 4 wt % aluminum when exposed to carbon supersaturated environments of between about 500 and about 650° C.
A carbon super-saturated environment is herein defined as an environment where the thermodynamic activity of carbon is greater than unity.
DETAILED DESCRIPTION
In many high temperature (300 to 850° C.) hydrocarbon-processing applications, structural components such as reactors and heat exchangers can be degraded by a carbon-induced corrosion known as metal dusting. Since the rate of such corrosion can sometimes exceed ˜25 millimeters per year (1000 mils per year), controlling it is important for both economic and safety reasons.
One aspect of the invention herein described uses a metal that suppresses graphite deposition, which is an essential step in metal dusting corrosion, and thereby controls metal dusting. For practical use such a metal must be economically attractive and reasonably high melting. In the present invention, copper and copper-based alloys are utilized as the surface contacting the carbon super-saturated environment which causes metal dusting corrosion.
The invention is specifically applicable, but not limited, to process streams where CO—H 2 mixtures constitute the predominant metal dusting medium.
The copper or copper based alloys can either be used to construct the apparatus surfaces which are susceptible to metal dusting such as reactors, or, alternatively, a coating of copper or copper based alloy can be utilized to protect an underlying surface susceptible to metal dusting.
When utilizing coatings, the copper or copper alloys can be applied to the surfaces to be protected by any technique known in the art for such an application. For example, plating, cladding, painting, chemical vapor deposition, sputtering etc.
When utilized as a coatings, the thickness of such coatings will range from about 10 to about 200 microns, preferably from about 50 to about 100 microns, or alternatively about 2 to about 100 microns in thickness.
Alternatively, these compositions can be directly used as metal dusting resistant alloys. When used either as coatings or as alloys, the range of application is expressed by the following table.
TEMPERATURE
METAL
° C.
AMOUNT WT %
Cu—Sn
Up to about 650
About 0.1-about 2 wt % Sn
Cu—Sn
Up to about 500
About 0.1-about 5 Sn
Cu—Sn
Up to about 400
About 0.1 to about 8 wt % Sn
Cu—Ga
Up to about 650
About 0.1 to about 2 wt % Ga
Cu—Ga
Up to about 500
About 0.1 to about 5 wt % Ga
Cu—Al
Up to about 650
About 0.1 to about 4 wt % Al
Cu—Al
Up to about 500
About 0.1 to about 8 wt % Al
Cu—Sn—Ga
Up to about 650
About 0.1 to about 2 wt % of Sn
and Ga combined
Cu—Sn—Ga
Up to about 500
About 0.1 to about 5 wt % of Sn
and Ga combined
Cu—Sn—Al
Up to about 650
About 0.1 to about 2 wt % Sn
and about 0.1 to about
4 wt % Al
Cu—Sn—Al
Up to about 500
About 0.1 to about 5 wt % Sn
and about 0.1 to about
8 wt % Al
Cu—Ga—Al
Up to about 650
About 0.1 to about 2 wt % Ga
and about 0.1 to about 4 wt %
Al
Cu—Ga—Al
Up to about 500
About 0.1 to about 5 wt % Sn
and about 0.1 to about 8 wt %
Al
Cu—Sn—Ga—Al
Up to about 650
About 0.1 to about 2 wt % of Sn
and Ga combined and about 0.1
to about 4 wt % Al
Cu—Sn—Ga—Al
Up to about 500
About 0.1 to about 5 wt % of
Sn and Ga combined and about
0.1 to about 8 wt % Al
Surfaces susceptible to metal dusting, as described herein include those surfaces of an apparatus or reactor system that are in contact with carbon supersaturated environments at any time during use, including heat exchangers, piping, etc.
When a mixture of the above alloys is utilized, if the alloy is being exposed to a carbon supersaturated environment at temperatures up to about 500° C. any combination of metals is acceptable. However, for temperatures of about 500 to about 650° C., the alloy should contain no more than about 2 wt % Sn and Ga combined.
EXAMPLES
Rectangular coupons of Fe-1.25 Cr-0.5 Mo alloy, which is considered for application as a heat exchanger material, were exposed to different CO—H 2 mixtures in a thermogravimetric unit at 1000° F. (538° C.). In each case, the corrosion rate was measured by microscopically measuring the recession of the alloy surface with respect to an inert marker. A plot of the metal dusting rate as a function of the hydrogen content in a CO—H 2 gas mixture is shown in FIG. 1 . The metal dusting rate is seen to go through a maximum corresponding to the 50 CO: 50 H 2 gas mixture. Therefore, this gas mixture composition is used as the corrosive environment in all the example studies.
The resistance of Cu and Cu-Sn alloys to metal dusting corrosion at 500° C. is shown in FIG. 2 . Since metal dusting is generally accompanied by carbon deposition, the dusting rate correlates with mass gain due to carbon deposition. While copper itself is quite resistant to metal dusting corrosion, the addition of Sn significantly improves the corrosion resistance.
The maximum temperature of application depends upon the Sn content. This is because Sn tends to vaporize at high temperatures. As shown in FIG. 3, a Cu-5Sn alloy or coating can be used up to about 500° C. Above this temperature, the performance deteriorates due to Sn vaporization. For Cu-8Sn alloy, FIG. 4, 400° C. is an acceptable upper temperature limit. | A method for inhibiting metal dusting corrosion of surfaces exposed to supersaturated carbon environments comprising constructing said surfaces of, or coating said surfaces with a copper based alloy. The invention is also directed to a composition resistant to metal dusting. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a system and a method used for generating water vapor so as to provide a controlled humidity environment. More particularly, it relates to an apparatus and method which may have, among other applications, the control of humidity in a wood drying kiln.
2. Prior Art
Lumber drying kilns put 20,000 to 100,000 board feet (or more) of various species of lumber, with various dimensions in the kiln, and then heat the closed kiln to between 1000 and 1800 Fahrenheit (approximately 380 to 820 Celsius) for many days to extract moisture from wood. Thicker pieces of harder wood take longer to dry, sometimes up to 45 days (or longer). A major difficulty in drying wood is that the surface of the wood dries out more quickly than the center of a given piece. The result is checking, cracking, crazing or warping of the wood surface. Since surface clarity is the selling feature for cost of the dried wood, the value of the wood is greatly diminished or reduced to zero due to such checking, cracking, crazing or warping.
In general, the normal approach used in a wood drying kiln is to gradually increase the temperature, while controlling the moisture levels in the kiln using the differential between wet bulb and dry bulb temperature sensors.
The benefits of controlling humidity in the kiln include maintaining a given drying schedule and obtaining surfaces with no checking, cracking, crazing or warping, or shortening the processing or drying time. The higher temperatures allow shorter drying periods for reaching the desired 6 to 8% moisture levels of dried wood by maintaining the humidity at a higher level when higher temperatures are used.
A conventional approach for maintaining higher humidity is to use hot steam in the kiln. However, the use of steam often raises the dry bulb temperature of the kiln at too high a rate. Further many plants do not have sufficient steam capacity to provide the required amount of steam. Typically a plant has a given boiler, and over the course of many years has added several kilns. There is enough steam available to dry the wood, but not enough to condition it by controlling the humidity level.
Most boilers used in the kiln drying industry are rated to provide steam at 15 lbs. per square inch. A general rule is that five BTU of steam energy are needed per board foot per hour for conditioning. Typically, in a seven day drying cycle the first two days dry off the surface water (or ice). After that, for the next four to five days, moisture is added to the kiln to prevent the checking. As an example, in a 30,000 board foot kiln, the amount of steam required at 5 BTU/board foot times 30,000 board feet equals 150,000 BTU per hour, or approximately five horsepower continuously.
Another approach is to use high-pressure steam to inject atomized water into the kiln. This method is expensive and requires energy for the boiler to produce or atomize the moisture, while keeping the dry bulb temperature from dropping.
A variety of approaches have been suggested for vaporizing liquids. For example, U.S. Pat. No. 4,604,109 by Koslow discloses an apparatus for separating contaminants from a fluid using a vacuum chamber and at least one rotating plate disposed within the chamber. The contaminated fluid is flung off the rotating disk in the form of a fine mist of droplets from which the contaminants evaporate. The purified droplets are then collected.
U.S. Pat. No. 4,833,895 to Johnson discloses a spin disk evaporator including a pan suspended from a cage enclosing a motor rotating a spin disk and a fan for moving an air stream across the pan and outward for the evaporator. The disk includes a cone-shaped tip immersed in water held in a sump portion of the pan. Rotation of the disk causes a film of water to be picked up by the tip and moved across the water transfer surface in a circumferential wall of the disk. Water collected on the inner surface of the wall separates and moves through grooves from the inner surface of the wall across the end of the wall to the outer surface. Water exits from the grooves and a circular head and is dispersed into the air stream as extremely fine water particles.
The approaches outlined above do not provide an apparatus or method for producing large quantities of water vapor in an inexpensive and efficient manner. Further, these approaches do not provide any suggestion of the manner in which water vapor can be produced efficiently and inexpensively for use in a wood drying kiln.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an apparatus and a method to readily generate water vapor efficiently and inexpensively.
It is another object of the invention to use the generated water vapor to control the humidity in an apparatus such as a wood drying kiln.
It is a further object of the invention to prevent the occurrence of undesirable defects in wood such as checking, cracking, crazing or warping, by inexpensively and efficiently controlling the humidity in a wood drying kiln.
The invention is directed to an apparatus for generating water vapor comprising at least one hydrophilic disk; a water supply structure for supplying water so that the water is deposited on the at least one disk; and means for rotating at least one disk at a speed sufficiently high so that water, which is deposited thereon is caused to leave at least one disk in the form of a mist or aerosol of very small water particles which evaporate to generate the water vapor (humidity).
A disk in accordance with the invention may comprise a water absorbing fabric affixed to the disk. An adhesive layer, such as an epoxy, may be disposed between the disk and the fabric for bonding the fabric to the disk. The fabric may be one of a woven and a non-woven fabric, and may be comprised of a material selected from the group consisting of a polyester, a cotton and a cellulose. Alternatively, a layer of a phosphate may be disposed on the disk so as to render the disk hydrophilic.
The disk or disks may be rotated by an electric motor, a hydraulic motor or a pneumatic motor. The disk or disks may be directly attached to the shaft of the motor. The apparatus may be combined with a wood drying kiln, the apparatus being placed within the kiln to provide a source of water vapor as the temperature of the kiln is controlled to dry wood placed in the kiln.
The invention is also directed to a method for providing water vapor, comprising rotating at least one hydrophilic disk at speeds sufficiently high to fling a fine mist of water particles from the disk; and providing water to said at least one disk.
Another aspect of the invention is a method of drying wood in a kiln, comprising heating air in the kiln; adding water vapor to the air by providing water to at least one hydrophilic disk, rotating the disk or disks at speeds sufficiently high to generate a mist of fine water particles, and circulating the air to which water vapor has been added to dry the wood. This method may be thought of as lumber conditioning; that is the process used to relieve stresses that build up in lumber as a result of drying of the lumber.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing aspects and other features of the present invention are explained in the following description, taken in connection with the accompanying drawings, wherein:
FIG. 1 is a cross-sectional view of a wood drying kiln in accordance with the invention.
FIG. 2 is a side elevational view of the humidifying apparatus, in accordance with the invention, of FIG. 1 .
FIG. 2A is a top plan view of a hydrophilic disk having radially extending grooves useful in the humidifying apparatus, in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there is shown a cross-sectional view of a wood drying kiln 10 incorporating features of the present invention. Kiln 10 is of the package loaded type, although the present invention may be applied to various other types of kilns such as, for example, a lineshaft, double track, compartment kiln, or to applications other than kilns. Although the present invention will be described with reference to the single embodiment shown in the drawing, it should be understood that the present invention can be embodied in many alternate forms of embodiments. In addition, any suitable size, shape or type of elements or materials could be used.
Kiln 10 has a generally rectangular housing defined by insulated walls 12 and 14 , and an insulated roof 16 , the insulation being necessary to keep heat contained therein. A doorway 18 having a movable door 20 through which wood packages 21 may be placed into and removed from kiln 10 is provided. The wood is supported on a floor 22 , generally of concrete. A fan deck 24 , having air circulation openings 26 and 28 , together with walls 12 and 14 define a plenum chamber through which hot air is circulated to dry the wood placed therein. Openings 26 and 28 have respective heat control baffle 30 and vent baffle 32 , the positions of which are controlled by respective ropes 34 and 36 , routed over respective pulleys 38 and 40 .
As well known in the art, a control room 42 is provided for housing control and process condition recording equipment. A so called wet bulb temperature sensor 44 is used to generate a signal from which is derived a control for the position of vent 32 , while a so called dry bulb temperature sensor 46 is used to generate a signal from which is derived a control for the position of heat control baffle 30 . A fan 48 having a large diameter blade assembly 50 , typically on the order of thirty six to seventy two inches (91.4 cm to 182.9 cm) in diameter, which is turned by a motor 52 , is used to circulate the air in kiln 10 . The air is heated by steam containing tubes or pipes 54 . Air chimneys 56 with automatic vents 58 are provided in roof 16 . The operation of the fan 48 , heat control baffles 30 and vent baffle 32 , and the amount of steam circulated through pipes 54 , and other aspects of the drying process in kiln 10 (including periodic reversal of the direction of air flow by reversing the direction or rotation of motor 52 ), are controlled by suitable control devices in control room 42 .
Referring to FIG. 2, in accordance with the present invention, instead of spraying steam into the fan deck region of kiln 10 , a humidifying apparatus 60 in accordance with the invention is used. A disk 62 , mounted for rotation therewith on the shaft 63 , of a motor 64 , is caused to rotate at a high rate, such as 3600 rpm. Motor 64 may be electrically, hydraulically, mechanically or pneumatically driven (or may be driven by any other equivalent means). A hub 65 , configured to receive shaft 63 and affixed thereto by any of several well known techniques, including at least one set screw 67 , may be welded to disk 62 in a manner which does not distort disk 62 . A source of water, such as a feed pipe 66 , drops water directly onto the spinning disk, at its center, or as close to the center as possible. The water feed to apparatus 60 by pipe 66 may be controlled by a relative humidity sensor (not shown), or wet bulb temperature sensor, so that water is supplied only when the humidity falls below a predetermined or preprogrammed level, which may vary with time, as the wood is dried. The water is caused, by centrifugal force, to be directed toward the outer circumference of disk 62 , where it is desired that it be flung therefrom in the form of a fine mist of water particles, in the order of 5 to 20 microns in diameter. In fact, the relationship that defines the size of droplets is explained in the above mentioned U.S. Pat. No. 4,604,109 to Koslow.
A problem that may occur is that the water may not wet the surface of disk 62 , which may be formed of a stainless steel to assure adequate strength and corrosion resistance. In this case, the water will bounce off at positions other than the rim, and will not be adequately vaporized. This will result in less than the proper humidity being maintained, which may cause the abovementioned defects of checking, cracking or crazing to occur.
In accordance with the present invention, disk 62 is hydrophilic. Disk 62 may have a hydrophilic coating or layer placed thereon to assure that the water wets the disk 62 , or is absorbed thereon, so that it may be carried to the outer periphery of disk 62 in a controlled manner before being propelled therefrom.
While a very thin layer of a phosphate may be deposited on disk 62 to enhance surface wetting, there is a tendency for this surface layer to wear off in a relatively short time with use. While this approach is of value for some applications, it requires frequent maintenance. For example, it may be necessary to have spare disks and to change the disks in order to keep a process running. Such interruption or lack of continuity may be undesirable in some processes, such as the wood drying process described herein, and adds to costs, in terms of lost time and the requirement for an additional inventory of parts.
Also in accordance with the invention, these difficulties may be avoided by affixing a hydrophilic layer 68 , such as a hydrophilic, non-woven fabric, to the surface (generally the upper surface) of disk 62 on to which the water is caused to flow. Layer 68 may be affixed to the surface of disk 62 with a layer 70 of an adhesive, such as, for example, an epoxy resin. To assemble the fabric to disk 62 , first the surface thereof is suitably prepared, by for example scoring, so that the epoxy will readily adhere thereto. Then, a thin layer 70 of the epoxy is applied to the surface of disk 62 . A piece of fabric 68 larger than the size of disk 62 is then stretched over disk 62 . Epoxy layer 70 is then allowed to set. Excess fabric extending beyond the circumference of disk 62 is then trimmed off, by use of a suitable cutting implement. If necessary, disk 62 may be spin balanced, for example by placement of suitable weights (not shown) placed at locations about its circumference, on the side opposite that of fabric 68 (the underside), in a manner well known in the art, to prevent undesirable vibrations which may adversely effect the life of bearings that support motor shaft 63 .
By hydrophilic, it is meant that disk 62 takes in water so that the water does not bounce off the disk 62 without being vaporized. The water is then available to be conducted to the edge of disk 62 , and leaves the rotating disk in the form of a very fine mist. It will ha recognized that structures other than those shown herein may achieve the same result. For example, disk 62 may be configured as a sandwich structure or assembly with a top and bottom plate, and the top plate having a central opening for receiving water. A hydrophilic material may be disposed between the two plates to receive the water and to conduct the water to the periphery of the assembly. Alternatively, disk 62 may be machined with a series of preferably deep, radially extending grooves to receive the water and to conduct the water to its periphery, as shown in FIG. 2 A. This disk may be the lower one of the sandwich type structure discussed above.
EXAMPLE
Disk 62 may have a diameter of approximately 10 inches (25.4 cm) and a thickness of approximately 0.2 inch (0.5 cm). A non-woven fabric made of a hydrophilic material or a woven cloth, such as one made from cotton may be adhered to disk 62 by a water resistant epoxy, of a type well known in the art. The disk 62 may be rotated at 3600 rpm by a totally enclosed, fan cooled, fractional horsepower motor of a type well known in the art, suitable for high temperature applications. Such motors are readily available from a number of manufacturers. At this speed of rotation, the mist formed will be distributed about a theoretical particle diameter of approximately 18 microns. This distribution will be maintained as long as the rate at which water is deposited on disk 62 does not significantly approach a maximum rate Q (max) defined in the abovementioned U.S. Pat. No. 4,604,109 to Koslow. In this example Q (max) is approximately 10 gallons (40 liters) per minute.
Such small water particles (or small droplets which may be characterized as an aerosol) evaporate at an extremely rapid rate, especially in the heated environment of a wood drying kiln. While such evaporation may cause some cooling, and additional heat may be needed to maintain a drying temperature program, the situation is fail-safe, in that a slightly lower temperature will not damage the wood, because it will not contribute to the creation of the checking, cracking, crazing or warping mentioned above.
In accordance with the size of the kiln, more water vapor may be required than can be supplied by a single rotating disk. Several assemblies as described herein may be utilized, as required. In addition or alternatively, with suitable selection of motor size, as described in the above mentioned patent to Koslow, multiple disks may be mounted on a single shaft, and each disk supplied with water to be vaporized.
Depending upon the particular application of the apparatus in accordance with the invention, the diameter of the rotating disk may be varied. Disk sizes much smaller and much larger than the example set forth herein may be used, with constraints imposed by the fineness of the mist that is to be generated, as set forth in the above mentioned patent to Koslow.
It may also be desirable to provide protection against motor failure or an interruption in the supply of electricity to an electric motor used to rotate the disk, which could lead to water being dropped on the fan deck if the motor were not spinning to vaporize the water. This can be avoided by placing an electrically operated valve (not shown) in the water supply system to automatically shut down the flow of water if the motor speed drops or if the motor stops. A centrifugal switch (not shown), such as those used to switch motor start windings (that close when the motor is operating below a predetermined rotational speed) can be used to provide an appropriate control signal, with modifications to open below such speed and remove the electrical supply to a normally closed electrically operated water supply valve.
In most cases, it is recommended that an anion/cation water softener be used to remove hardness and heavy metals, such as iron, for the local water supply that is used to provide water to the apparatus in accordance with the invention.
Thus, the present invention provides superior product control, as there is no staining due to the deposit of moisture droplets upon the wood that is being processed. Maintenance requirements are greatly reduced as there are no steam injection nozzles to clean. Further, the ability to accurately control moisture, or relative humidity, with no steam related temperature increase allows more precise and reliable control, resulting in shorter, more effective conditioning time periods. The rotating disk typically ejects water particles of less than 20 microns in size at a speed of 140 mph (226 kph). These particles immediately vaporize, thus providing humidity at ambient kiln temperature. This is done with low energy use.
It should be understood that the foregoing description is only illustrative of the invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims. | An apparatus and method for generating water vapor or humidity, useful in a variety of applications, including a wood drying kiln. The apparatus may contain a hydrophilic disk, a water supply structure that supplies water so that the water is deposited on the hydrophilic disk, and a motor for rotating the disk at a speed sufficiently high so that water which is deposited on the disk is caused to leave the disk in the form of a mist of particles or droplets which are sufficiently small to evaporate rapidly to generate the water vapor. The disk may be made hydrophilic by covering with a fabric. | 5 |
BACKGROUND OF THE INVENTION
The field of the invention pertains to electric devices to open and close draperies or curtains, and in particular, to devices that automatically control the position of the draperies or curtains in response to light or heat.
A light actuated electric drapery drive is disclosed in U.S. Pat. No. 4,471,275 wherein the circuit provides overload protection in addition to providing opening and closing of the draperies by manual switches or the light sensor. The light sensor actuates the circuit to operate the drive motor upon sufficient lighting level.
U.S. Pat. No. 3,675,023 discloses combined heat and light sensors for mounting atop a building. The combined heat and light sensors are mounted for electro-mechanically driven movement to follow the sun during the day. In response to the heat and light striking the sensors with changing levels and direction throughout the day, the sensors control the opening and closing of draperies or Venetian blinds progressively about the building as the sun progresses about the building.
Of more general interest is U.S. Pat. No. 3,529,214 which discloses light responsive systems to automatically control street lamps. The systems include means in the circuit to ignore sudden flashes of light so that the street lamps will not be extinguished in response to a sudden and momentary flash of light.
SUMMARY OF THE INVENTION
In response to the need for a simple and very compact electric drive for draperies or curtains that is automatically actuated in response to changed light level, applicant has invented the very compact and unobtrusive curtain puller disclosed below. The curtain puller is meant to replace the conventional spring loaded tensioner which typically includes a freely rotatable pulley for engagement with the loop of drapery cord and means to attach to the floor or wall.
The new light actuated curtain puller externally appears much like the above tensioner with a pulley adjacent the top and spring tensioned means extending from the bottom for attachment to a floor or wall adjacent the draperies or curtains. Atop the new puller is a light sensing means with a cap to control the direction from which light may enter the light sensing means. As with the tensioner the new puller is preferably positioned behind or adjacent the edge of the drapery or curtain near the side of the window. In this location the cap can shield the light sensing means from the interior lighting and permit light to enter from the window and behind the drapery or curtain.
Inside the new puller is a miniature high torque electric motor having the drive shaft attached to the external pulley. In the preferred embodiment the motor is a reversible alternating current motor optically isolated from a direct current control circuit. The direct current control includes means triggered by the light sensing means to cause a first timing circuit to begin a timing cycle. If the first timing cycle is completed a second timing cycle begins with the start of a motor operate signal.
A flip flop circuit retains the current state of the motor and draperies and permits operation of the motor only for a change of the draperies.
Alternatively, optional configurations can use a direct current reversible electric motor and motor drive or a digital decoder can be substituted for the light sensing means to receive and decode control signals passed through the building wiring.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front exterior view of the curtain puller;
FIG. 2 is a side exterior view of the curtain puller;
FIG. 3 is a top view of the curtain puller;
FIG. 4A is an electric schematic for the photoelectric cell circuit;
FIG. 4B is an electric schematic for the timing and status circuit; and
FIG. 4C is an electric schematic for the power supply and motor drive circuit.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Illustrated in FIGS. 1, 2 and 3 is the exterior box or container 10 for the curtain puller. The box 10 may be constructed of metal or plastic halves that merely snap together or are fastened together with mechanical fasteners. Adjacent to the top of the box is a separate cover piece 12 open at the top and affixed to the front of the box 10. Within the cover 12 is a drive pulley 14 mounted on a motor drive shaft extending from a small electric motor 16 within the box 10. The pulley 14 engages the drapery or curtain cord 18 in turn extending downwardly about the pulley 14 and upwardly to the curtain rod (not shown). Thus, the electric motor 16 drives the curtain cord 18 to open or close the curtains or drapes. In other words, the motor 16 moves the object or curtains from an open first position to a closed second position or vice versa.
Below the box is a bracket 20 that may be attached to the wall of a house adjacent a window with mechanical fasteners through the holes 22 in the bracket. Within the bracket 20 is a transverse rod 24 to which a pair of springs 26 are attached at their lower end. The upper ends of the springs 26 are attached to a second transverse rod 28 in turn affixed to the inside of the back of the box 10. The springs 26 provide suitable tensioning for the curtain cord 18.
Atop the box 10 is a small shield 30 which may be manually rotated about a vertical axis. The shield 30 has an opening 32 to permit light to enter therein. Inside the shield is a photocell connected to the internal circuitry of the curtain puller. A 110 volt AC power supply cord as indicated at 34 extends into the box 10 and is attached to a rectifier and motor power circuit indicated at 36. Also inside the box 10 is a printed circuit board 38 to which are attached the electric elements comprising the control circuit for the curtain puller. As shown the box 10 encloses the entire electric control and power supply for the curtain puller. The box 10 is not substantially larger than a conventional spring tensioner for a curtain cord loop.
FIGS. 4A, 4B, and 4C illustrate the control and power circuitry for the curtain puller. With the exception of the 110 volt AC power supply cord 34 and plug for the electrical power to the curtain puller, the control and power circuitry is entirely contained within the box 10. Referring in particular to FIG. 4C, a fuse F1 and transformer T1 in the 110 volt AC supply provide power to a regulator circuit comprising a diode bridge 40 and an integrated circuit regulator REG-1. The regulator circuit provides 12 volts DC power to the control circuit illustrated in FIGS. 4A and 4B and to the isolator circuit including opto-isolators IC1 and IC2 shown in FIG. 4C. The transformer T1 also provides AC power at reduced voltage to the pulley drive motor 16 through the triacs Q1 and Q2. Triacs Q1 and Q2 are in turn triggered by signals respectively from opto-isolators IC1 and IC2. In other words, the transformer and regulator circuit act as a power supply means for supplying power from the 110 AC power source to the control circuit and motor. A suitable motor 16 is a reversible 24 volt 60 cycle AC motor. A reversible DC motor might be substituted for motor 16 with suitable changes in the power supply to provide DC current and solid state switching means in substitution for triacs Q1 and Q2.
The opto-isolators or optical couplers IC1 and IC2 provide electrical isolation between the AC power for the motor 16 and the low voltage substantially DC control signals in the control circuit shown in FIGS. 4A and 4B. The signal through the opto-isolators IC1 and IC2 is provided by a 12 volt DC signal in turn controlled by a pair of transistors Q3 and Q4. The pair of optically isolated connection circuits is between transistor Q4 and triac Q1 and between transistor Q3 and triac Q2. Thus, the control of rotational direction of the motor 16 is determined by a signal from opto-isolator IC1 to triac Q1, or for the other direction, by the signal from opto-isolator IC2 to triac Q2.
The control circuit identified by the reference 38 to a printed circuit board within the box 10 comprises in FIGS. 4A and 4B a photo-electric cell Q5 which is contained within the hooded cover 30 at the top of the box 10. In response to a sufficient increase or decrease in light the photo cell Q5 provides an input to an integrated circuit IC3 which in turn provides an output at pin 7 of a sudden up or down voltage change as indicated by arrows 42 and 44. In other words, the photoelectric cell Q5 is a light sensing means for detecting changes in levels of light, i.e., presence or absence of light in the daytime and nighttime, respectively. The sudden change in voltage up 42 or down 44 is provided as an input to pin 4 of integrated circuit IC4 which in turn massages the signal to provide through integrated circuit IC7 a reset and start signal illustrated by the "one shot" 46 at pin 4 of integrated circuit IC7. The reset and start "one shot" 46 in turn is provided to pin 6 of a dual timer integrated circuit IC5.
A suitable integrated circuit IC4 is a Motorola Monostable Multivibrator MC14538B or equivalent. Integrated circuit IC5 is a National Semiconductor Dual Timer LM556 or equivalent.
The reset and start "one shot" 46 is also provided through integrated circuit IC8 from pin 3 to the base of transistor Q6, which with the associated circuitry and dual timer IC5 provides a ramp function timing signal that increases in voltage continuously from the moment that the "one shot" reset and start signal is received. Typically, this ramp function, as indicated schematically by arrow 48 on the XY plot adjacent transistor Q6, constantly increases the charge on capacitor C6 until a prespecified voltage is reached. Each time the signal from the photocell Q5 passes a threshold of increasing light or decreasing light an up or down voltage change is generated by integrated circuit IC3 and sensed at the base of transistor Q6 to reset the ramp function output 48 by discharging capacitor C6. Typically the ramp function circuit elements connected between transistor Q6 and pins 1, 2 and 3 of integrated circuit IC5 are specified to provide about a 15 minute time period from start or reset until a specified voltage is reached. Thus, short term changes in light level sensed by the photo electric cell Q5 do not result in actuation of the control circuit beyond resetting the ramp function output 48.
Once the specified ramp function voltage is reached, the second timer of integrated circuit IC5 is actuated by the output 1 at pin 5 to T2 pin 8. The second timer includes the circuit elements connected to pins 7, 11, 12 and 13 of integrated circuit IC5. The potentiometer P1 provides adjustable means for setting the length of time the motor 16 operates by setting the specified ramp function maximum voltage for the second timer.
With actuation of the second timer an output 2 signal at pin 9 is provided to pin 3 of integrated circuit IC6 which acts as a flip-flop or latch to determine the current state or position of the motor 16 and thereby determine the current position of the curtain. A suitable integrated circuit IC6 is Motorola Dual Flip-Flop MC14013B or equivalent. The flip-flop integrated circuit IC6 thereby permits or does not permit the motor to operate depending upon the direction of operation of the motor the previous time the motor was actuated to move the curtain. In other words, the flip-flop or latch acts as a latching means for determining the current position of the motor in either of the first and second positions and for actuating the motor to move the object or curtain to the position opposite the current position of the object or curtain. The status of the integrated circuit IC6 can be easily determined by the light emitting diode D8 which is connected to pin 9 of integrated circuit IC6 and illuminated when the curtain is in the closed position. A by-pass or a manual switch S2 is also provided so that the curtain can be conveniently opened or closed as desired during the night or during the day. The manual closure or opening of the curtain is sensed through the connection to pins 2 and 5 of integrated circuit IC6. The output from integrated circuit IC6 pins 1 and 2 respectively provide one-half of the control to the base of transistor Q4 or the base of transistor Q3 thereby determining the direction of rotation. The other half of the control is provided by the output at pin 9 of the dual timer IC5.
Once actuated by the output at pin 9 of integrated circuit IC5 the motor operates for a period of time necessary to move the curtain as set by the exterior circuitry and potentiometer P1 of the second timer of dual timer IC5. The second timer circuit is also actuated by engaging the manual switch S2 to also start the motor running with the second timer. In either case the motor runs for a set period of time sufficient to open or close the curtain. In summary, the flip-flop circuitry only permits the motor to operate when either the signal from integrated circuit IC3 or from the manual switch S2, if thrown, provides for movement of the curtain opposite to that of the previous movement of the curtain. | An automatic electro-mechanical device for opening and closing a curtain or drapery in response to changed light striking a photoelectric cell on the device. The device comprises a miniature high torque reversible electric motor and control packaged in a container of substantially the same size as a conventional cord tensioner of curtains or draperies. To close the drapes at sun-down and open the drapes at sun-up automatically without actuation if the lighting changes for short periods of time, the device comprises a dual timer circuit with individual ramping circuits. One timer circuit monitors the sustained presence or absence of light for a predetermined amount of time. The other timer regulates the motor drive run time. A flip flop circuit signals the current state of the curtains or drapes by providing memory of the last directional movement of the motor. | 0 |
FIELD OF THE PRESENT INVENTION
[0001] The present invention relates to the field of communication devices, e.g. wireless communication devices. More particularly, the present invention relates to the field of signal equalisation, especially minimum mean square error equalisation. The present invention especially relates to an equaliser for a communication device, a method of equalising one or more received signals and a software program product for carrying out the method.
BRIEF DESCRIPTION OF THE PRIOR ART
[0002] Minimum Mean Square Error (MMSE) equalisers are well known means to improve the performance of a communication system. MMSE equalisers are known to minimize the error power which is due to inter-symbol interference (ISI) and noise.
[0003] Equalisers are employed in the frequency domain and in the time domain and may be accordingly classified as frequency domain equalisers (FDE) or time domain equalisers (TDE). Single tap equalisers are directly applicable for equalisation in the frequency domain. Multi tap equalisers are directly applicable in the time domain. However, equalisation in the time domain may also be based on a single tap equaliser and equalisation in the frequency domain may also be based on a multi tap equaliser.
[0004] Single-carrier (SC) and multi-carrier (MC) communication systems are well known. MC systems can be implemented using, for example, but not exclusively, orthogonal frequency division multiplexing (OFDM), multi-carrier code division multiple access (CDMA), wavelet based multi-carrier techniques, OFDM-CDMA and other combinations and variations thereof. In MC systems, traditionally, but not necessarily, equalisation is performed in the frequency domain.
[0005] Traditionally, communication channels with a single input and a single output (SISO communication systems) were employed, in recent times however, communication channels with multi inputs and/or multiple output have enjoyed a widespread use, which leads the notion of MISO, SIMO and MIMO communication systems.
[0006] To implement a conventional MMSE equaliser, a division (or inversion) operation is required. Given for example the conventional single tap, SISO, MMSE equaliser, which performs equalisation of a received signal by multiplying the received signal with a factor g which is defined by
[0000]
g
=
h
*
h
2
+
σ
n
2
,
(
0
)
[0007] whereby σ n 2 represent the noise variance, h represents the channel response and * denotes complex conjugation, the dividend h* has to be divided by the divisor |h| 2 +σ n 2 . In order to reduce the computational complexity, the division operation may be implemented deploying a look-up table (LUT). Hereby, the inverse of the divisor is taken from the LUT and the division operation is replaced by the (computationally less complex) multiplication of the dividend with the inverse of the divisor. This, however, introduces the problem that the look-up table has to be very large in order to cope with the large dynamic range of the channel responses and the noise variances.
[0008] S. Kaiser, “On the performance of Different Detection Schemes for OFDM-CDMA in fading channels”, IEEE International Conference on Communications (ICC '1995), vol. 3, pp. 1722-1726, Seattle, USA June 1995 discloses a plurality of OFDM-CDMA equaliser structures including a controlled equalisation and a MMSE equalisation. In the controlled equalisation according to Kaiser, one of two equaliser structures is selected depending on the received signal power, which results improved zero forcing (ZF) equaliser. In the MMSE equalisation according to Kaiser, the signal-to-noise ratio (SNR) parameter is set to a fixed value, which results in a suboptimal MMSE equaliser.
[0009] The problem to be solved by the present invention is to provide for an equaliser, communication device and method for equalising one or more received signal with reduced complexity and a corresponding software program product.
SUMMARY OF THE INVENTION
[0010] This problem is solved by an equaliser for a communication device comprising a filter calculator for determining a channel power value based on one or more channel response values and selecting one of two or more equaliser structures based on said channel power value and based on at least one threshold value for separating the channel power values into at least two ranges; and a filter for equalising one or more received signals according to the selected equaliser structure.
[0011] Advantageously, said filter calculator is adapted to select a first equaliser structure in case said channel power value is below a first threshold value and to select a second equalising structure in case said channel power value is above said first threshold value.
[0012] In a first embodiment of the equaliser, said filter calculator, in accordance with said first equaliser structure, is advantageously adapted to calculate a first product of the conjugate complex of a channel response value with the inverse value of a noise variance value. Advantageously, said filter calculator, in accordance with said second equaliser structure, is adapted to calculate a second product of the conjugate complex of a channel response value with the inverse value of the sum of said channel power value and said noise variance value. Advantageously, said filter calculator is adapted to calculate said first product based on a first look-up table and said second product based on a second look-up table, said first and second look-up tables having different quantisations.
[0013] In a second embodiment of the equaliser, the equaliser advantageously comprises a memory for storing a predetermined value and said filter calculator, in accordance with said first equaliser structure, is adapted to calculate a first product of the conjugate complex of a channel response value with either said predetermined value or the inverse value of said predetermined value. Advantageously, said filter calculator, in accordance with said second equaliser structure, is adapted to calculate the sum of said channel power value with either said predetermined value or the inverse of said predetermined value and to calculate a second product of the conjugate complex of a channel response value with the inverse of said sum. Said predetermined value or its inverse may, for example, correspond to a maximum value of a SNR or a minimum value of a noise variance.
[0014] Advantageously, said filter calculator is adapted to select a third equaliser structure in case said channel power value is above a second threshold value that is larger than said first threshold value and to select said second filter structure in case said channel power value is above said first threshold value and below said second threshold value. In this case, said filter calculator, in accordance with said third equaliser structure, is advantageously adapted to calculate a third product of the conjugate complex of a channel response value with the inverse value of said channel power value based on a look-up table.
[0015] The equaliser according to the present invention may be employed in a MIMO communication device. Advantageously in this case, said channel power value is the largest element of a channel power matrix. Advantageously, said filter calculator is adapted to calculate said channel power matrix by multiplying the Hermitian transpose of a channel matrix with the channel matrix, whereby said channel matrix comprises said one or more channel response values.
[0016] In a fourth embodiment of the equaliser, said filter calculator, in accordance with said first equaliser structure, is advantageously adapted to calculate a first matrix corresponding to the Hermitian transpose of said channel matrix multiplied by the inverse of a noise variance value. Advantageously, said filter calculator is adapted to calculate the inverse value of said noise variance value using a look-up table.
[0017] In a fifth embodiment of the equaliser, the equaliser advantageously comprises a memory for storing a predetermined value, whereby said filter calculator, in accordance with said first equaliser structure, is adapted to calculate a first filter matrix corresponding to the Hermitian transpose of said channel matrix multiplied by either said predetermined value or the inverse of said predetermined value. Advantageously, said filter calculator, in accordance with said second equaliser structure, is adapted to calculate a second matrix corresponding to a conventional minimum mean square error equaliser matrix whereby the value of a noise power parameter required for calculating said second filter matrix is set to said predetermined value.
[0018] In an embodiment, the equaliser advantageously comprises at least two look-up tables for implementing corresponding at least two division or inversion operations, said at least two look-up tables having a different quantization. Advantageously, each of said division or inversion operations corresponds to a different one of said equaliser structures.
[0019] Advantageously in case of said second and fifth embodiment of the equaliser, said first threshold value is given by the product of a first factor with said noise variance value.
[0020] Advantageously, at least one of said equaliser structures corresponds to an, at least approximated, minimum mean square error equaliser structure or to an, at least approximated, suboptimal minimum mean square error equaliser structure.
[0021] The problem is further solved by a communication device comprising an equaliser according to the present invention.
[0022] The problem is further solved by a method of equalising one or more received signals comprising the steps of determining a channel power value based on one or more channel response values; selecting one of two or more equaliser structures based on said channel power value; and equalising said one or more received signals according to the selected equaliser structure. Hereby, at least one of said equaliser structures corresponds to an, at least approximated, minimum mean square error equaliser structure or to an, at least approximated, suboptimal minimum mean square error equaliser structure; According to the method a first equaliser structure is selected in case said channel power value is below a first threshold; and a second equaliser structure is selected in case said channel power value above said second threshold.
[0023] The problem is further solved by a software program product which, when executed in a processing device, is adapted to carry out the method of equalising one or more received signals according to the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 shows a schematic representation of a first embodiment of the communication device according to the present invention.
[0025] FIG. 2 shows a schematic representation of a second embodiment of the communication device according to the present invention.
[0026] FIG. 3 shows a schematic representation of a third embodiment of the communication device according to the present invention.
[0027] FIG. 4 shows a schematic representation of an embodiment of the equaliser according to the present invention.
[0028] FIG. 5 shows a schematic representation of an embodiment of the communication method according to the present invention.
[0029] Same reference numerals, even when used in different Figures or in relation to different embodiments, relate to the same elements.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] The present invention proposes new and inventive implementations of the MMSE equalisation principle which reduce the size of the LUT needed for the division operation and, generally, provides for a reduced complexity of the equaliser and receiver. In the embodiments described in the following, various MMSE and sub-optimal MMSE equaliser implementations are provided in which one from two or three equaliser structures is selected depending on the power of a received signal.
[0031] FIG. 1 shows schematic representation of an example of an SC/FDE SISO communication system comprising a first embodiment of the receiver 1 according to the present invention and a transmitter 20 .
[0032] The receiver 1 comprises a radio frequency (RF) part 2 and a baseband part 3 . The RF part has an antenna 4 connected to a low noise amplifier/downconversion unit 5 . A signal received by the antenna 4 is amplified and downconverted. The downconverted signal is forwarded to a filter 6 of the baseband circuit 3 . After filtering, the signal is digitized using an analogue-to-digital converter (ADC) 7 and is provided to a channel estimator 8 and an FDE 9 . Based on the digitized signal (e.g. based on a preamble section including training sequences) a channel estimation and synchronisation/timing information is obtained by the channel estimator 8 . Signals from the channel estimator 8 are applied to an FDE 9 . The FDE 9 comprises a fast Fourier transformator (FFT) 10 for transforming the digitized signal into the frequency domain. The transformed signal is then equalised by an equaliser 11 , of which the constitution and operation will be described in detail later on. The equalised signal is then transformed back into the time domain by an inverse fast Fourier transformator (IFFT) 12 and provided to a demodulator 13 , which may, but need not, be implemented as a soft demodulator. The demodulator 13 performs a demodulation operation (known also as ‘symbol demapping’) and may be implemented e.g. as a soft demodulator. After being deinterleaved by an deinterleaver 14 , the signal is decoded (channel decoding) by a channel decoder 15 whereby received data is obtained which is put out as a bit stream.
[0033] The transmitter 20 comprises a baseband part 21 and an RF part 22 . In the baseband part, a transmit data bit stream is encoded (channel encoding, e.g. based on a forward error correction code) by a channel encoder 23 and subsequently interleaved by an interleaver 24 . A modulator 25 applies a modulation operation (known also as “symbol mapping” or “constellation mapping”) to the interleaved data which is further converted into an analogue signal by a DAC 26 and filtered by a filter 27 . The analogue, filtered signal is then forwarded to an upconversion/power amplifier unit 28 and the upconverted and amplified signal is emitted using an antenna 29 .
[0034] It is stressed that the communication system shown in FIG. 1 and the communication systems that are described later on in relation with FIGS. 2 and 3 are just typical examples of communication systems for which the present invention might be employed. Not all of the elements shown in the Figures are essential, some elements might be replaced with other or modified elements, some elements might additionally be added and some elements might be reordered as is known in the art of communication systems.
[0035] FIG. 2 shows a schematic representation of an example of an OFDM communication system comprising a second embodiment of the receiver 41 of the present invention and a transmitter 50 .
[0036] The receiver 41 comprises the RF part 2 and a baseband part 43 . After downconversion in the RF part 2 , a received signal is transformed by a fast Fourier transformator 46 and is provided to a channel estimator 47 and the equaliser 11 of the baseband part 43 . Based on the signal (e.g. based on a preamble section including training sequences) a channel estimation and synchronisation/timing information is obtained by the channel estimator 47 . A signal from the channel estimator 47 is applied to the equaliser 11 , of which the configuration and the operation will be described in detail later on. The equalised signal is provided to a channel decoding/demodulating unit 49 , which comprises the chain of demodulator 13 , deinterleaver 14 and channel decoder 15 as described above, and from which the received data is put out as a bit stream.
[0037] The transmitter 50 comprises a baseband part 51 and the RF part 22 . A transmit data bit stream is input in a channel coding/modulation unit 53 comprising the chain of channel coder 23 , interleaver 24 and modulator 25 described above. The thus encoded data is transformed by an IFFT 54 . The (inverse) Fourier transformed data is further processed by a DAC/filtering unit 55 , comprising the chain of DAC 26 and filter 27 before it is emitted by the RF part 22 .
[0038] Before the operation of the equaliser 11 is explained, the operation of a conventional single tap MMSE equaliser is described. This equaliser equalises the received signal by multiplying the received signal by a complex number g. In a multi-carrier system, like the one of FIG. 2 for example, a separate single tap equaliser is needed for each carrier or frequency l. Although the SC/FDE communication system of FIG. 1 is a single carrier communication system, the single carrier is split into a plurality of carriers or frequencies by virtue of and in between the FFT 10 and IFFT 12 . Therefore, also in the SC/FDE system of FIG. 1 a separate single tap equaliser is needed for each carrier or frequency l obtained by means of the discrete Fourier transformation. The conventional equaliser for each frequency l is given by
[0000]
g
l
=
h
l
*
h
l
2
+
σ
n
,
l
2
,
(
1
)
[0000] whereby h l represents the channel response, an σ n,l 2 represents the noise variance, * represents complex conjugation and |.| represents the absolute value. The channel response h l is determined by the channel estimator 8 , 47 and corresponds to (or is at least part of) the channel estimation mentioned above. |h l | 2 is the channel power and corresponds to the power (“signal power”) of the received signal (without noise components). The noise variance corresponds to the power (“noise power”) of noise in the received signal. There may be determined only one noise variance for all frequencies l. The noise variance is equivalent to the inverse value of the signal-to-noise ratio (SNR) (σ n,l 2 =1/SNR l ). As was described above, a LUT is used to determine the inverse of the divisor |h l | 2 +σ n,l 2 in order replace the division by a multiplication and reduce the complexity of calculation. However, because the dynamic range of (|h l | 2 +σ n,l 2 ) −1 for a wide range of noise variance and channel powers can be very large, a big LUT is needed.
[0039] The present invention proposes new and inventive implementations of the MMSE equalisation principle which reduces the size of the LUT and, generally, provides for a reduced complexity of the equaliser and receiver.
[0040] For the sake of brevity, the subscript l, denoting the carrier or frequency number, will be dropped in the following, but it must be understood that a separate equaliser is required and separate equalisation is carried out for each carrier or frequency l also in case of the present invention.
[0041] According to the present invention, the equaliser has a plurality of equaliser structures. In the following, embodiments with two or three equaliser structures are provided. According to the present invention, an equaliser structure is selected depending upon a channel power value. Hereby, at least one threshold value is used. The channel power value is an element of a range of possible channel power values. The one or more threshold values divide (separate) the range of possible channel power values into at least two (sub-)ranges. The one or more threshold values correspond to boundaries of the subranges. To each subrange corresponds one equaliser structure.
[0000]
TABLE 1
Three Structure MMSE Equaliser
Equaliser
LUT
|h| 2 condition
structure selected
needed
if |h| 2 < (lower limit × σ n 2 )
g = h * × 1 σ n 2
(2)
Yes
if (upper limit × σ n 2 ) ≧ |h| 2 ≧ (lower limit × σ n 2 )
g = h * h 2 + σ n 2
(3)
Yes
If |h| 2 > (upper limit × σ n 2 )
g = h * h 2
(4)
Yes
[0042] In Table 1, a three structure MMSE Equaliser according to a first embodiment of the equaliser according present invention is defined. The two threshold values (lower limit×σ r 2 ) and (upper limit×σ n 2 ) divide the possible range of channel power values |h| 2 into the three ranges |h| 2 <(lower limit×σ n 2 ), (upper limit×σ n 2 )≧|h| 2 ≧(lower limit×σ n 2 ) and |h| 2 >(upper limit×σ n 2 ). In this first embodiment, a division operation is needed for each equaliser structure and, therefore, a LUT is required for each of the structures. The parameters lower limit and upper limit can be used to trade off performance with complexity.
[0043] An advantage of this three structure equaliser is that three smaller LUTs are needed rather than one large LUT.
[0044] When plotting the function y=l/x one sees that the graph is steep near the y-axis (x=0) and flat far from the y-axis. Thus, a small change in x amounts to a large variation in y when being close to the y-axis. Therefore, it is advantageous to provide LUTs with different quantization. A LUT has an input variable and an output variable. The LUT maps an input value to an output value. The input variable corresponds to the divisor of which the inverse value is to be looked-up. The inverse value corresponds to the output value. The term quantization as used in here refers to the quantization of the input variable. Of course, the quantization of the input variable influences the quantization (average step size) of the output variable. That is, a finer quantization of the input variable corresponds to a finer quantization (average step size) of the output variable. Advantageously, a LUT that corresponds to a smaller divisor has finer quantization (of the input variable) than a LUT that corresponds to a greater divisor. Hence, in the first embodiment of the equaliser 11 , the LUT corresponding to equation (2) is quantized fine, the LUT corresponding to equation (4) is quantized coarse and the LUT corresponding to equation (3) has a quantization in between (middle quantization).
[0045] The number and size of the LUTs can be further reduced by setting σ n 2 to a fixed value denoted by NP. The fixed value may be chosen to be the minimum value, σ n,min 2 , of the noise variance, that will presumably be encountered when operating the equaliser/receiver according to the present invention. This is equivalent to saying that the fixed value may be chosen to be the inverse of the maximum value, SNR max , of the SNR that will presumably be encountered during the operation of the equaliser/receiver according to the present invention. Thus, for example, NP=σ n,min 2 =1/SNR max . The fixed value NP may be determined at the stage of development of the equaliser 11 or receiver 1 , 41 and be preset (stored) in the equaliser 11 during production. Because, in this case, σ n 2 has not to be determined by the receiver 1 , 41 , the complexity of the receiver is reduced so that it can be produced at lower cost. At the time of the determination and storage of the fixed value NP also its inverse INP=1/NP may be determined and stored. Alternatively, the inverse value INP may be calculated from NP e.g. at start up or in an initialisation phase. Alternatively, INP may be stored and NP may be calculated from it. Applying this to the first embodiment, a second embodiment of the equaliser according to the present invention, corresponding to a sub-optimal three structure MMSE equaliser, is obtained. The suboptimal three structure MMSE equaliser is summarized in the following Table 2.
[0000] TABLE 2 Three Structure suboptimal MMSE equaliser Equaliser LUT |h| 2 condition structure selected needed if |h| 2 < (lower limit × NP) g = h * × INP (5) no if (upper limit × NP) ≧ |h| 2 ≧ (lower limit × NP) g = h * h 2 + NP
(6) Yes If |h| 2 > (upper limit × NP) g = h * h 2
(7) Yes
In this second embodiment of the equaliser 11 , for the equalising structure described by equation (5) no division operation is needed and therefore no LUT is necessary. Furthermore, since NP is fixed, the dynamic range of the LUT needed for the evaluation of equation (6) is lower than the dynamic range of the LUT needed for the evaluation of equation (3), so the size of the LUT is reduced. Advantageously, the LUT used for evaluating the equation (6) has a different (finer) quantization than the LUT used for evaluating the equation (7).
[0046] For some applications it may be beneficial to merge the LUT tables needed for equations (6) and (7). This alternative two structure approach, corresponding to a third embodiment of the equaliser according to the present invention, is defined in the following Table 3.
[0000] TABLE 3 Two structure suboptimal MMSE equaliser Equaliser LUT |h| 2 condition structure selected needed if |h| 2 < (lower limit × NP) g = h * × INP (8) no if |h| 2 ≧ (lower limit × NP) g = h * h 2 + NP
(9) Yes
The concepts described above can also be extended to MIMO, SIMO and MISO systems (MISO, SIMO and SISO systems may be seen as special cases of a general MIMO system). FIG. 3 shows an example of an OFDM MIMO system with two transmit paths (transmitter antennas) and two receive paths (receiver antennas). Generalisation to more than two transmit and/or receive paths is obvious. The communication system comprises a receiver 61 corresponding to a second embodiment of the receiver according to the present invention and a transmitter 80 .
[0047] The receiver 61 comprises an RF part 62 and a baseband part 63 . The RF part 62 comprises two parallel RF parts 2 (as shown in FIG. 1 and 2 ) each comprising an antenna 4 and a low noise amplifier/down conversion unit 5 . Two simultaneously received and parallely processed signals are provided in parallel to two FFTs 46 of the baseband part 63 . After being Fourier transformed in the FFTs 46 , each signal is provided to a channel estimator 67 and an equaliser 68 . Based on the signals (e.g. based on a preamble section including training sequences) a channel estimation and synchronisation/timing information is obtained by the channel estimator 67 . A signal from the channel estimator 67 is applied to the equaliser 68 , of which the configuration and the operation will be described in detail later on. The equalisation process in the equaliser 68 will generally “mix” the parallel input signals into parallel output signals, each of which is then provided to a corresponding demodulation/channel decoding unit 49 . The plurality of units 49 generate a corresponding plurality of bit streams which are serialized by a parallel-to-serial converter (P/S) 70 and put out as an output data bit stream.
[0048] The transmitter 80 comprises a baseband part 81 and an RF part 82 . An input data bit stream is split into two parallel data streams by a serial-to-parallel converter 83 of the baseband part 83 . Each data stream is processed by a corresponding chain of a channel coding/modulation unit 53 , IFFT 54 , DAC/filtering unit 55 and up-conversion/PA unit 28 and, finally, is emitted (as a signal) by a corresponding antenna 29 .
[0049] A conventional MMSE equaliser for a MIMO system with n R =1, 2, 3, . . . receive paths (e.g. receive antennas) and n T =1, 2, 3, . . . transmit paths (e.g. transmit antennas) (for true MIMO n R , n T ≧2 holds) multiplies the equaliser matrix G (of size n R ×n T ) by the received symbol vector r (of size n R ×1) for each carrier or frequency l. The equaliser matrix G is given by
[0000] G =( H h H+σ n 2 I ) −1 H H , (10)
[0000] where H is a n R ×n T matrix whose elements represent the channel response from the different transmit paths to the different receive paths, I is the n T ×n T identity matrix, σ n 2 represents the noise variance, (·) H denotes the Hermitian transpose and (·) −1 denotes the inverse (inverse matrix). The channel matrix H (one for each carrier or frequency l) is determined by the channel estimator 67 as (at least part of) the channel estimation. H H H is a n T ×n T channel power matrix H H H having elements corresponding to channel powers.
[0050] A two structure MIMO MMSE equaliser, corresponding to a fourth embodiment of equaliser according to the present invention, is defined in the following Table 4.
[0000] TABLE 4 Two structure MIMO MMSE equaliser Equaliser LUT Matrix H H H condition structure selected needed inv. if all elements of H H H < (lower limit × σ n 2 ) G = ( 1 σ n 2 ) × I H H
(11) Yes No Otherwise G = (H H H + σ n 2 I) -1 H H (12) No Yes
In the fourth embodiment, when all elements (channel powers) of the channel power matrix H H H are lower than lower limit×σ n 2 (e.g. lower than ⅕×σ n 2 ), the structure according to equation (11) is selected. This is equivalent to saying that, when the largest element of the channel power matrix is smaller than lower limit×σ n 2 , the structure according to equation (11) is selected. For the evaluation of equation (11) only a LUT (for determining the inverse of σ n 2 ) but no matrix inversion is required. Forming the inverse matrix is a computationally very complex operation. Therefore a big advantage is gained.
[0051] A further reduction in complexity is obtained by using the suboptimal MMSE approach described above. A two structure suboptimal MMSE MIMO equaliser, corresponding to a fifth embodiment of the equaliser according to the present invention, is defined the following Table 5.
[0000] TABLE 5 Two structure suboptimal MMSE MIMO equaliser LUT Matrix H H H condition Equaliser structure selected needed inv. if all elements of H H H < G = INP × I H H No No (lower limit × NP) (13) Otherwise G = (H H H + NP × I) −1 H H No Yes (14)
In this embodiment, there is neither required a matrix inversion nor a LUT for the evaluation of the equation (13).
[0052] FIG. 4 shows a schematic diagram of an equaliser 90 which applies to any one of the first to fifth embodiment of the equaliser according to the present invention. The equaliser 90 comprises a memory 92 in which at least some of the following information items are stored: NP, INP, lower limit, upper limit, lower limit×NP, upper limit×NP, one or more look-up tables. (Which items are stored depends on which of the first to fifth embodiments is implemented and is evident from the above description). The equaliser 90 further comprises a filter calculator 94 which has access to the memory. The filter calculator 94 receives the channel estimation (h or H) and, eventually, σ n 2 selects the filter structures according to the above defined conditions and calculates the filter (filter is described in terms of filter information g or G) to be applied to the received signal in accordance with the selected equaliser structure. The equaliser 90 further comprises a filter 96 which filters (performs the actual equalisation processing) the received one or more signals according to the filter information and puts out the filtered (equalised) one or more signals. As noted above, this processing is repeated for each carrier or frequency l using the parameters/input/channel estimation corresponding to the subcarrier or frequency l. At least some of the NP, INP, lower limit, upper limit, lower limit×NP, and upper limit×NP may be frequency dependent.
[0053] The present invention can likewise be seen in a corresponding method of equalising 30 one or more received signals. FIG. 5 shows a schematic diagram of an embodiment of the method of equalising one or more received signals.
[0054] In step S 2 a channel power value is determined based on one or more channel response values.
[0055] In a step S 4 , one of two or more equaliser structures is selected based on the channel power value. At least one of said equaliser structures corresponds to a minimum mean square error equaliser structure or a suboptimal minimum mean square error equaliser structure. In case the channel power value is below a first threshold, a first equaliser structure is selected in step S 4 and in case the channel power value above said first threshold a second equaliser structure is selected in step S 4 .
[0056] In a step S 6 , a filter (i.e. filter defining information) is calculated according to the selected equaliser structure based on channel state information.
[0057] In a step S 8 , one or more received signals are filtered (equalised) according to the calculated filter. Since in step S 6 the filter is calculated according to the selected equaliser structure, the one or more received signals are equalised according to the selected equaliser structure.
[0058] The steps of the method are carried out according to the principles described above in relation with said first to third embodiment of the communication device and said first to fifth embodiment of the equaliser.
[0059] The present invention has been described with reference to an OFDM multi-carrier communication system. The present invention, may however also be employed in relation with other MC communication techniques and variants of OFDM including, as a non limiting example, multi-carrier code division multiple access (CDMA), wavelet based multi-carrier techniques, OFDM-CDMA and other combinations and variations thereof.
[0060] The present invention has been described based on embodiments using single tap equalisers. Multiple tap equalisers however suffer from the same problems of high computational complexity due to divisions and matrix inversions (even a plurality of divisions and matrix inversions has to be carried out). Therefore, the present invention may be equally applied to multiple tap equalisers. For example, a multi tap SC/TDE equaliser/receiver may be realized using the present invention.
[0061] To implement the conventional MMSE equaliser, an estimate of the SNR is required. Using the suboptimal approach described above in relation with the second, third and fifth embodiment of the equaliser according to the present invention, only the communication channel has to be estimated but no estimate of the SNR is required, so that a SNR evaluation circuit/algorithm can be dispensed with.
[0062] It is noted, that for some receiver implementations (e.g. some OFDM receiver implementations) the division operations of equations 1-4, 6, 7, 9 and 11 can be performed as in internal scaling in the demodulator (e.g. the demodulator 13 , 49 ) and, therefore, can be ignored in the equaliser block. In this case, the division operations performed in the demodulator can be implemented using a LUT in the same way as if they had been implemented in the equaliser. Such splitting of equaliser processing between the equaliser block and the demodulator is however not possible for an SC/FDE receiver (like e.g. the receiver 1 depicted in FIG. 1 ), since the equalisation and the demodulation are performed in different domains. It must be understood that the equaliser according to the present invention may be seen as comprising the demodulator performing the internal scaling (or at least the relevant portion thereof).
[0063] It is noted that each of the receivers 1 , 41 , 61 can, for example, be part of a pure receiving device or can be part of a receiving and transmitting device. In the later case, the antenna 4 can be a receiving as well as a transmitting antenna. Also, each of the transmitters 20 , 50 , 80 can be part of a pure transmitting device or can be part of a transmitting and receiving device (e.g. said receiving and transmitting device). In the latter case, the antenna 29 may be a transmitting and receiving antenna (e.g. the antennas 4 and 29 may be the same entity). | The present invention relates to the field of communication devices, e.g. wireless communication devices. More particularly, the present invention relates to the field of signal equalisation, especially minimum mean square error equalisation. The present invention especially relates to an equaliser for a communication device, a method of equalising one or more received signals and a software program product for carrying out the method. The present invention reduces the size of a look-up table needed for a division operation and, generally, provides for a reduced complexity of the equaliser and receiver. The equaliser for a communication device comprises a filter calculator for determining a channel power value based on one or more channel response values and selecting one of two or more equaliser structures based on said channel power value and based on at least one threshold value for separating the channel power values into at least two ranges; and a filter for equalising one or more received signals according to the selected equaliser structure. Advantageously, at least one of said equaliser structures corresponds to an, at least approximated, minimum mean square error equaliser structure or to an, at least approximated, suboptimal minimum mean square error equaliser structure. | 7 |
BACKGROUND AND BRIEF DESCRIPTION OF THE INVENTION
Sound wave digitizers are known in the art as shown, for example, in U.S. Pat. No. 4,317,005 and in U.S. Pat. No. 4,012,588. In U.S. Pat. No. 4,317,005, a pair of linear or Sell-type transducers bound a pair of intersecting edges of a data surface and transmit acoustic waves to a passive reflecting target, such as a stylus. Reflected waves are detected and the timing thereof determined to locate the target by its coordinates. In FIG. 3 of U.S. Pat. No. 4,012,588, a transmitting transducer emits sound waves from an edge of a data space and reflected waves are received by a pair of receivers at the corners of the same edge of the data space and isolated from the transmitting transducer by acoustic barriers, and a triangulation computation is made to determine the location of an object in the data space.
Low cost narrow beam electrostatic transducers are well known in the art. In my U.S. application Ser. No. 496,158, filed May 19, 1983, and entitled "EFFICIENT LOW COST TRANSDUCER SYSTEM" now U.S. Pat. No. 4,530,077 I disclose a novel ultrasonic transducer using a low cost narrow beam electrostatic transducer coupled with a beam transformer or acoustic lens located in the near field thereof for controllably expanding the transmitted beam in one dimension.
The object of the present invention is to provide an improved two dimension sound wave digitizer. A further object of the invention is to provide a sound wave digitizer or data entry device using low cost transducers. Another object of the invention is to provide a compact sound wave digitizer.
In accordance with this invention, a pair of sound wave beam transducers transmit a pair of angularly related sound beams along orthogonally related paths across a data surface; the beam transducers being spaced from intersecting edges of the data surface a distance substantially equal to the maximum edge dimension of the data surface so that the sound beams impinging on an object over the data surface are substantially orthogonal. The sound beams are preferably in the ultrasonic range propogated in air.
In accordance with a preferred form of the invention, a pair of low cost narrow beam electrostatic transducers combined with conical beam transformers are spaced at a distant remote point from the edge of a data surface wherein a randomly movable object, such as a stylus or human finger or other object, may be located. The spacing of the transducer from the edge is such that the angle at any intersection point of the beams is substantially orthogonal. The beams are folded 180 degrees to achieve compactness and the form factor is enhanced by the beams being coplanar and coupled to the folding acoustic mirror by intersecting coplanar acoustic horns. Sound absorbing material is utilized to form beam boundaries in said acoustic horns.
BRIEF DESCRIPTION OF THE DRAWINGS:
The above and other objects, advantages and features of the invention will be better understood when considered with the following specification and accompanying drawings wherein;
FIG. 1 is a schematic view illustrating the orthogonality effect as used in the invention,
FIG. 2 is a schematic view for the trigometric analysis of the orthogonality effects as used in the invention,
FIG. 3 is a schematic view further illustrating the location of the target areas according to the invention,
FIG. 4(a) is a plan view of a preferred transducer positioning for target area D of FIG. 3 after folding the transducer beam paths 180 degrees.
FIGS. 4(b) and 4(c) are schematic sectional views through plans B-B' and C-C', respectively.
FIGS. 5(a)-5(c) illustrate the further embodiment of the invention where the beam paths before folding are non-coplanar,
FIG. 6 illustrates an embodiment of the invention where the sonic beam paths are folded about 90 degrees,
FIG. 7 illustrates one preferred form of a target,
FIG. 8 is a simplified block diagram of the electronic system incorporating the invention,
FIGS. 9(a)-9(e) are wave form diagrams illustrating the system timing,
FIG. 10 is a schematic electrical diagram of a preferred form for the analog electronic system of FIG. 7,
FIG. 11 is a schematic diagram of a preferred circuit for the digital electronic section shown in FIG. 7,
FIG. 12 is a microcontroller logic diagram of algorithm showing the output signal format,
FIG. 13 is a top plan view of a preferred form of the invention where ambiguity and error avoidance is provided by modified acoustic horns.
DETAILED DESCRIPTION OF THE INVENTION
The invention disclose herein is, in its preferred embodiment, a folded path ultrasonic, two-dimension digitizer. A two-dimension digitizer is a device which enables encoding of two-dimensional graphic data and/or digital encoding of a position in a two-dimension coordinate system such as serial digital bit streams, for example. In its preferred embodiment, the invention employs two ultrasonic transducers 10 and 11 deployed at either end of a base line 12 to measure two ranges R1 and R2 to an acoustic-target through the conventional method of timing the arrival of the echo signal from the target 15. According to the invention, and as shown later, the path of the acoustic pulse from either transducer to the target and back may be folded (that is the transducer and target need not be in the same plane) to achieve a greater base-line length without extending the area required for the device and by folding the beams 180 degrees, the volumetric space is greatly reduced.
As noted above, heretofore, sound wave digitizers employed linearly distributed, specially designed transducers to avoid the errors inherent to compact range-range positioning techniques. This invention permits the use of low cost centrally located commercially available ultrasonic transducers instead of the linear transducers and thereby gaining a cost advantage and at the same time, achieving a higher degree of accuracy.
The uncertainty in determining position through two measurements of range from different known locations is affected not only by the precision of the range measurement but also by the orthogonality between the two measurements. In this invention orthogonality is meant the degree to which the intersection of the two range vectors approximates a right angle. The orthogonality effect is illustrated by FIG. 1 wherein the area of uncertainty is portrayed for two cases: 1(a) range vectors (R 1 (a) and R 2 (a)) at a right angle to each other, and 1(b) both range vectors R 1 (b) and R 2 (b)) lying along the base line. Note that the maximum linear uncertainty of position (εb) or 1(b) is several times the maximum uncertainty (εa) of 1(a).
The term long-baseline range-range positioning system, is meant to define a system wherein the base-line length is comparable to or larger than the range to the target from either end of the base-line. For mathematical convenience in analyzing a long base-line system, a conservative approximation of the maximum uncertainty may be made by assuming that the wave fronts are linear instead of arcuate. FIG. 2 illustrates the approximating wherein the included angle between the vectors (R1 and R2) from the transducer locations to the target position is labeled θ. Trigonometric analysis reveals that the linear uncertainty (ε) is related to the range uncertainty (δ) by the equations:
ε/δ=sec (θ/2); for θ obtuse, and
ε/δ=sec (π-θ/2); for θ acute.
The value for ε/δ is a minimum and equal to √2 along the locus of points that satisfy the condition θ=π/2 (90°); everywhere else ε/δ>√2. Thus, according to this invention, one of the controlling criterion in designing a long baseline range-range positioning system is the degree of degradation in ε/δ that is deemed permissible.
The square root of two, (√2) is a commonly used factor of permissible degradation, and will be used herein for an example of the design process: set the maximum allowable ratio (ε/δ) max. equal to √2x) (ε/δ) min., wherein (ε/δ) min. =√2, and compute (ε/δ) max.=2. Further, ε/δ=√2 only when θ=2 π/3 or π/3 (120° or 60°, respectively). Therefore, the maximum permissible degradation occurs along the loci of points satisfying the above conditions for the value of θ as plotted in FIG. 3.
The foregoing consideration constrains the target area to lie between curves A and B of FIG. 3. If it is required that the target area to be square in outline, then the maximum and minimum areas that satisfy the criteria are as drawn in FIG. 3 and labeled C and D. With target area C, the perpendicular bisector of the baseline is the perpendicular bisector 13 of the square; while with target area D, the perpendicular bisector of the baseline lies along the diagonal of the square. It is obvious that other rectangular areas may be fitted between the limiting curves A and B and that the target areas need not have straight or linear sides. The surface under the target areas correspond to data surfaces where a large expanse is available to support a clear path between the echo ranging transducers and the target. An example is digital encoding of information from a wall mounted chalkboard wherein the chalk is the target and the information is generated during the course of a lecture. However, the data surface underlying target area C does not permit convenient design of a folded path for ultrasonic wave propagation.
Target area D is convenient to the design of a folded path ultrasonic two-dimension digitizer in the following ways: first, the axes of folding may be maintained parallel to the edges of the target area; and second, acoustic paths from the two transducres are symmetrically located about the diagonal of the square. The first feature produces a physically compact design and the second permits economics in acoustic, electronic and logic (software) design.
A plan view of the transducer positions for target area D after folding the paths by 180 degrees is presented in FIG. 4a (and FIG. 13). FIGS. 4b and 4c are section views through planes B-B' and, C-C', respectively, which are normal to the plan view on FIG. 4a. Ultrasonic energy is propogated from the transducers 10Y and 11X to the right angle reflectors 20Yand 21X, respectively, and thence up into the data plane of the target area 25, to the target 26 and is then reflected back along the same paths to the transducer locations. The two-way propagation times are a measure of the range between the target and the respective transducer and are used to compute position of the target in the conventional manner of range-range systems. In FIGS. 4(b) and 4(c) beam transformers 29 and 30 are portions of conical acoustical reflective surfaces and are disclosed in greater detail in my above-identified application.
A problem with the folded path configuration of FIGS. 4b and 4c is related to the transducer beam patterns. The problem, illustrated by FIG. 4a, is that ultrasonic energy on a side lobe path 28-a, 28-b from one of the transducers (10Y) will enter into the folded path of the other transducer and echo off the target with two possible results: (1) it will be detected as if it were in the intended path and give seriously erroneous results, or (2) it will interfere with the echo signal from the intended path and produce a phase shift in the detected signal to produce errors less than a half wavelength of the ultrasound. The first result is easily countered through control of sidelobes, use of automatic gain control, and judicious selection of threshold, as is the usual case with good sonar design practice. The second result can only be ameliorated by such procedures and designs, but never entirely eliminated.
Thus, the folded path configuration of FIG. 6 and the intersecting acoustic horns of FIG. 13 essentially do away with the cross talk problem.
The folded paths of FIG. 6 are only coplanar on the target level. In consequence; the paths are distinctly separate but with the penalty of an additional layer (thickness) to the device. Component parts corresponding to FIG. 4 are primed.
It is noted that the data surface or target area 25 may be a flat plate display, such as DC or AC plasma panels, LCD and electroluminescent display panels and the target may be a finger or pointer. In that case, the precision required may not be finer than a half wavelength of the ultrasonic wave and the more compact configuration of FIG. 4 and FIG. 13 is more desirable.
Also, in the case where the target area is the face of a cathode ray tube 32, the path from the transducer 39 to the and transformer 40 may be folded by only 90 degrees by a 45 degree reflector 33 as shown in FIG. 6. The paths are then distinctly separate and cross talk will not be a problem. In this case, the folded path, ultrasonic, two-dimension, digitizer provides an economical means of interaction between a computer and untrained people. Obviously, folding from 180 degrees through any desired angle can be used to practice the invention. Although the drawings illustrate the 180 degree acoustic folding surfaces to be intersecting, it will be appreciated that they may be spaced a short distance so as to accomodate a flat plate display of the type referred to above.
TRANSDUCER DESIGN
High efficiency in the ultrasonic transducers provide higher signal-to-noise ratios and thus greater precision in the range measurements. However, as discussed previously, some applications do not require high precision and cheaper, less efficient, transducers may be employed.
A transducer suitable for low precision applications is the Matsushita Electronic Components Col, Ltd. Model EFR-RAB40K4 which provides a conical beam that is approximately 50-deg wide at the 3 db points when operated at 40 kHz. The Q of the transducer is approximately 16 and consequently it is not suitable for broadband (high resolution) operation. The beam widths best suited for the folded path configuration of Figures 4 and 6 is 40 degrees in the plane parallel to that of the display and as narrow as practical in the normal plane. At 40 kHz, the optimum beamwidth (determined by setting the near-field limit to the distance between the transducer and the reflector) is approximately 10 degrees if the distance is 16 inches. The Matsushita transducer unit provides signal-to-noise ratios less than optimum by the factor: ##EQU1##
As disclosed in my above-identified application, a more efficient transducer arrangement that is applicable to high precision applications includes a Polaroid® brand electrostatic transducer 10 and a beam transformer 29, 30. The Polaroid® transducer produces a conical ultrasonic beam at 50 kHz that is approximately 10-deg wide. The beam transformer 29, 30 is a 45 degree cone reflector that is placed in the near field of the transducer as illustrated by FIG. 4. The resulting beam acoustic axis lies in a plane normal to the axis of the cone (horizontal plane) and is in the direction of the displacement (d) of the center of the transducer 10 from the axis of the cone.
It is clear that when no displacement exists (d=o), the resulting beam is omnidirectional in the normal plane; and when the displacement is very large (d→∞), the resulting beam shape closely approximae the shape of the undisturbed transducer beam. The -3 db beam width in the plane containing the reflected acoustic axis and the axis of the cone (the vertical plane) varies from about 10 degrees at d→∞ to about 20 degrees at d=O. Transformed beamwidths are unpredictable in proportion to the unpredictability of the beam widths of the transducers themselves.
To produce the 40 degree beam in the horizontal plane that is optimum for the previously defined folded path configurations, tests indicate that the displacement should be approximately one inch (d=1 in.). The consequent beam width in the vertical plane is no more than 15 degrees and consequently, the resulting loss in signal-to-noise ratio is no more than 20 Log (10/15)=-3.5 db. The Polaroid brand transducer features a low Q (≈5.5) and therefore is more suitable for broadband (high resolution) operation.
ACOUSTIC TARGET
A preferred target shape is a right circular cylinder. The height of the cylinder need be no greater than the height of the acoustic path over the target surface (aboout 1.5 inches with the Polaroid® transducer). The radius of the cylinder may be as required to achieve a high target strength; however, the radius dimension must be added to the range dimension prior to calculating coordinates of the cursor. As shown in FIG. 9(a) and 9(b), the cursor 26 may take the form of cross hairs 140 on the bottom 141 of a transparent plastic cylinder 142. As shown in FIG. 7, a human finger serves quite well as the target.
ELECTRONICS SYSTEM
The system electronics is conventional and includes a digital control section and an analog sonar section. The simplified block diagram of FIG. 8 illustrates the relationship between the electronic sections and the ultrasonics. Pulse power is delivered to the transducers 10X and 10Y in an alternating fashion by the analog section 50 in response to synchronizing signals from the digital section 60. Echo, reverberation and noise signals from the transducers are processed by the analog section to provide precise timing signals to the digital section. In turn, the digital section 60 generates binary numbers that are functions of the ranges to the target from the two transducers. The numbers are subsequently used by special purpose or general purpose computers to compute cartesian coordinate of the cursor in a manner that is common and well known in the art. As is conventional, the circuitry is calibrated to take into account such as air temperature, humidity, etc.
Timing of the several signals is diagrammed in FIGS. 9(a)-(e). The digital section 60 establishes a fixed precise pulse repetition period (PRP) (FIG. 9a) between transmissions of the ultrasonic transducers 10X and 10Y. Just prior to each transmit pulse, the digital section 60 cause the analog section to switch from one transducer to the other (FIG. 9b). The analog section 50 amplifies the received signals and produces pulses with trailing edges that are precisely concurrent with the negative-going zero-crossings of the received ultrasonic signals (FIG. 9c).
The receiver input includes pulses that are related to the ultrasonic transmissions (T), to spurious reflections and reverberations within the folded path (R), to noise (N) and to the echo signal (S) from the target. The receiver output is thresholded to remove the noise pulses and transformed by a zero-crossing detector (FIG. 9d). Pulses (T) and (R) are ignored in the digital section by appropriate gating of the time counter.
In the digital section, the time counter is turned on at a fixed, precise time (t b ) after all (T) and (R) pulses are over for the repetition period. The counter is turned off at the time (t x or t y corresponding to the X or Y transducer) of the first negative-going zero-crossing of the echo from the target (9e). Subsequently, a binary representation of t x or t y is transmitted as data. The range to the cursor is: ##EQU2## where r is the radius of the target and c is the speed of sound.
FIG. 10 is a schematic diagram of a preferred circuit for the analog electronic section. Standard Polaroid Corporation transmitter circuits are energized alternately by transmit and transducer select signals from the digital section as previously described. Transducer outputs are switched into a four stage receiver 80: a preamplification stage 81 (3240 A), a time-varied gain stage 82 (CA 3006), a buffer stage 23 (3240 B) and a zero-crossing detector stage 84 (LM 3610). The zero-crossing detector is a conventional circuit wherein pin 11 (of LM 3610) is high and pin 9 is low when pin 1 (the input) is low, thus establishing a positive threshold voltage on pin 3. When the voltage on pin 1 exceeds that threshold, the threshold voltage on pin 3 reverts to zero while the output voltage on pin 9 goes high. At the instant that the input voltage on pin 1 goes back through zero, pins 11 and 9 revert to their previous state with the result that the trailing edge of the pulse on pin 9 is a precise timing signal.
FIG. 11 is a schematic diagram of a preferred circuit for the digital electronic section. A microcontroller 90 (Intel MCS 8048 or equivalent, for example), timed by 6 MHZ crystal 99, provides the synchronizing signals on transmit line 91 and transducer select line 67 to the analog section (FIG. 11) and the reset on line 92 and clock on line 94 signals to the range counter 95. The receiver output is inverted by inverter 96 and fed to a J-K flip-flop 97 in such a manner that the clock signal from the microcontroller 90 is gated off by gate 102 at the time of the first negative-going zero-crossing from the receiver after the counter 95 has been reset to zero.
The output of the counter 95 is sampled at the 12 bit data bus 97 by the microcontroller 90 and used therein to generate data bytes on lines D0-D7 which are subsequently transferred to an 825 USART 98, the USART is a programmable synchronous or asynchronous, receiver transmitter and receives timing signals from timer divider 106 which is driven by crystal 107. A reset circuit comprised of a switch 108, resistor 109 and capacitor 110 initiallizes timer divider 106 and microcontroller 90, and this is inverted by inverter 112 to initiallize USART 98. The USART 98, in an asynchronous mode, then converts the data to a serial bit stream which is transmitted via buffer 111 at a 4800 baud rate over a conductor 101 from buffer 102 to the computer (not shown) which is conventional and is used to convert the data into cartesian coordinates using the algorithm shown in FIG. 13. The circuit of FIG. 12 is designed to produce an output compatible with computer standard RS 232C, and frequencies and rates set forth in FIG. 13 are typical and exemplary and not mandatory.
The microcontroller cycles the signals in a manner that conforms to the logic diagram of FIG. 12. Delay times between transmit and reset counter are designed to produce t b of FIG. 9, and the value of which must be made available to the cartesian-coordinate computer. The baud rate of the USART output must be high enough to transmit all of the data each cycle. In addition to the time interval data (t x or t y ), each transmission must encode the transducer being used (X or Y) and in this example must encode the byte number. The latter requirement rises from the constraints imposed by using 8-bit logic to transmit 12 bit data.
In the embodiment shown in FIG. 13, the coplanar acoustic paths for the ultrasonic beams are acoustic horns 120 and 121 which have a common area 122. The acoustic paths are defined by acoustic absorber material 135 which avoid unwanted reflections and/or reverberations. These acoustic horns couple the ultrasonic energy from and to beam transformers 129 and 130 (corresonding to beam tranformers 29 and 30 of FIG. 4a) and transducer 10Y and 11X, respectively, and the beam folding reflectors 120Y and 121X, respectively. It will be noted that the axes of the beam paths is not symmetrical, which helps to avoid ambiguity and errors. The space 136 may be used to locate electronic circuitboards and the like.
While there has been shown and described the preferred emboidment of the invention, it will be appreciated that other modifications and changes can be made to the invention without departing from the spirit and scope thereof as set forth in the claims appended hereto. | A sound wave position digitizer has a pair of sound wave beam transducers, each spaced a predetermined distance from the edges of a data surface such that the beams intersect on the data surface at substantially orthogonal angles. The beams are folded by reflectors to achieve compactness and, to further improve the form factor, the beams are coupled to the folding reflectors by acoustic horns which intersect and have a common section. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to devices for dispensing viscous fluids including such diverse materials as grease and joint compound. More specifically, the present invention is concerned with dispensing devices which are hand-held and have provisions for discharging a viscous fluid from and charging a viscous fluid to a canister through a common conduit.
2. Description of the Prior Art
U.S. Pat. No. 2,430,608 discloses a service station installation including stationary grease pumps operated by compressed air, electricity or the like and mounted on grease drums. Such apparatus is in wide use and works very well in locations having a readily accessible source of compressed air or electricity.
Hand-held, manually operated grease guns are also known. Such grease guns are designed for use with a grease canister and include a manually operated mechanism for pressurizing grease and causing it to flow out of the through a conduit to a suitable coupling.
U.S. Pat. No. 3,987,869 entitled "Back Pack Lubrication System" discloses a motorized, back pack mounted grease dispensing device. The device includes grease cylinders and spring urged pistons for pressurizing grease within the cylinders, a conduit connecting the grease cylinders to a pump and a conduit connecting a discharge port of the pump to a grease gun. This device also includes a motor to supply shaft power to the pump and a battery power pack for supplying current to the motor. The patent discloses that the pump can be of the auger-type or of the piston type. The grease cylinders are provided with a detachable cap to enable the operator to remove the piston and refill the grease cylinders.
SUMMARY OF THE INVENTION
The present invention is a device for dispensing a viscous fluid from and charging a viscous fluid into a canister mounted on a housing of the device. Also mounted in the housing is a reversible auger-type pump including an auger having first and second ends. The first end of the auger is in communication with a nozzle conduit for conducting a viscous fluid between the first end of the auger and a nozzle provided on the nozzle conduit. The second end of the auger is in communication with the canister. The device further includes a motor and associated gearing for connecting the motor to the auger in driving relationship. Power cell means are provided to supply current to the motor. The polarity of the current so supplied is controllable by a switch so that, when current of a given polarity is supplied to the motor, the auger will rotate in a first direction and when the polarity of the current is reversed, the auger will rotate in a second opposite direction. When the auger is rotated in the first direction, it pumps a fluid from the nozzle conduit into the canister thereby filling it. When the auger is rotated in the opposite direction, it serves to pump fluid from the canister to and through the nozzle conduit for discharge. The device may be equipped with a two-speed gear box to provide additional control over discharge and filling rates in response to a variety of considerations including fluid viscosity. Additionally, the dispenser may be equipped for discharging a metered amount of fluid.
Accordingly, it is an object of the present invention to provide a device for dispensing a viscous fluid from and charging a viscous fluid into a canister expeditiously and conveniently.
Other objects as well as advantages of the present invention will be apparent from the following detailed description of the invention with reference to the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a drum of lubricant and a dispensing device incorporating features of the present invention and including means adapting the device for use in dispensing grease.
FIG. 2 is an exploded perspective view of the device shown in FIG. 1.
FIG. 3 is a cross-sectional view taken along the line 3--3 of FIG. 1.
FIG. 4 is a cross-sectional view taken through a gear box along the lines 4--4 shown in FIG. 2.
FIG. 5 is a schematic circuit diagram for the device of the present invention.
FIG. 6 is a sectional view through an attachment for use with the dispensing device for dispensing and applying joint compound to dry wall.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1, a device according to the present invention for dispensing a viscous fluid is indicated generally at 10. The device 10 comprises a housing having a first half 12 and a second half 14. The two halves are secured together by fasteners 16. A fluid canister 18 is attached to the housing. A fitting 20 is secured to an end of the housing opposite the fluid canister 18. Connected to and extending from the fitting 20 is a conduit 22 provided with a coupling 24. In FIG. 1, the coupling 24 is shown attached to a cone-shaped cover 26 of an associated drum 28 containing a lubricant 30. The drum 28 has a cone-shaped bottom 32 corresponding dimensionally with the cover 26. A spring 33 is positioned below the bottom 32 and biases it towards the top 26.
A conventional A.C. adapter 34 is wired to a base 36. The adapter 34 includes prongs 38 for insertion in a suitable A.C. power outlet (not shown). A power cord 39 electrically connects the adapter 34 with the base 36. The device 10 includes a first switch 40 and a second switch 42 as well as associated circuitry for controlling the distribution of power delivered to the device 10 from the adapter 34. The circuitry is discussed below in detail. A gear shift lever 44 is provided to select one of two gear combinations as discussed below in connection with FIGS. 3 and 4.
Turning now to FIG. 2, the contents of the housing halves 12 and 14 are shown. A power cell 50 is secured in the housing half 14 by clips 52. Power input terminals 54 of the bayonet type extend from the power cell 50. The terminals 54 are positioned to be accessible through apertures (not shown) provided in the housing half 12 for electrical connection with a suitable source of external power such as the base 36 (FIG. 1). Preferably, the adapter 34 is operable to convert A.C. power to D.C. power. It is also preferred that the power cell 50 is operable to store D.C. power produced by the adapter 34 for selectively supplying it to a motor. Alternative, the power cell 50 can comprise one or more non-rechargeable batteries thereby obviating the base 36 and adapter 34. In either case, the power cell 50 would constitute a self-contained source of power for the device 10 making it portable. It will be readily appreciated by those skilled in the art that other means for supplying power to a motor could be used in the device 10. For example, the power cell 50 could comprise an A.C. to D.C. adapter making the device 10 dependent on an external source of A.C. power.
The power cell 50 and associated circuitry discussed hereinbelow selectively provide power to a motor (not shown) mounted in a motor housing 56. An annular flange 58 is provided on the motor housing 56 and is coupled by suitable fasteners 60 to a corresponding flange 62 provided at one end of a gear box housing 64. Another flange 66 is provided at the other end of the gear box housing 64 which, in turn, is coupled by fasteners 68 to an adjacent flange 70 provided at one end of a pump housing 72. A complex flange 74 is provided at the other end of the pump housing 72. The complex flange 74 comprises a first flange 76, a groove 78, a larger second flange 80 and an exteriorly threaded section 82. Corresponding interior threads 84 are provided at one end of the fluid canister 18 for selective engagement with the threaded portion 82 of the complex flange 74 on the pump housing 72. Flanges 85 are provided at one end of the housing halves 12 and 14 and are configured to be received in the groove 78 when the device 10 is assembled.
A wheel 86 is secured by a fastener 88 to a motor shaft 90. The wheel 86 includes a depending cam 92 which is positioned to intermittently engage a cam follower 94 which is mounted on a switch 96. When activated, the switch 96 is operable to maintain a closed circuit between the power cell 50 and the motor in the motor housing 56 except when the cam 92 engages the cam follower 94. This provides a metering function for the pump housed in housing 72. This function will be described in more detail hereinbelow.
One end of an elbow 98 is connected to a port in the pump housing 72. A conduit coupling 100 is secured to the other end of the elbow 98 coupling it to one end of a conduit 102. The fitting 20 is provided at the other end of the conduit 102. The housing halves 12 and 14 are provided with conduit engaging flanges 104 adapted to snugly engage the conduit 102 when the halves 12 and 14 are assembled. Posts 106 provided in the housing halves 12 and 14 define internal bores 108 sized t receive fasteners 16 (FIG. 1). Notches 110, 111 and 112 are provided in the housing halves 12 and 14 to accommodate the switches 40 and 42 and the gear shift lever 44 (FIG. 1), respectively. A support block 114 is provided in each of the housing halves 12 and 14. Each block 114 is sized so that, when the halves 12 and 14 are assembled, the blocks 114 securely support the motor housing 56 and the other housings within the housing halves 12 and 14.
With reference to FIG. 3, details regarding the operation of the device 10 will now be described. Mounted for rotation within the pump housing 72 is an auger vane 116 mounted on a shaft 118. One end of the shaft 118 is journaled for rotation in a bearing plate 120 which is secured to the pump housing 72 by fasteners 122. Apertures 124 in the bearing plate 120 provide communication between the auger vane 116 and a fluid reservoir 126 which is defined, in part, by the fluid canister 18. The fluid reservoir 126 is further defined by a pressure plate 128 which is slidably mounted for axial movement within the canister 18. A seal is effected between the lubricant canister 18 and the pressure plate 128 by ring seals 130. A spring 132 is dimensioned and positioned to urge the pressure plate 128 towards the pump housing 72 and away from an end 133 of the fluid canister 18. One end of a cable 134 is secured to one end of the spring 132 while the other end of the cable 134 is secured to the other end of the spring 132 to prevent overextension of the spring. The spring places fluid within the fluid reservoir 126 under a positive pressure. The fluid canister 18 is vented at 135 to maintain atmospheric pressure on the non-pressure side of the pressure plate 128. When the reservoir 126 is full, the spring 132 will be compressed so that a post 136, mounted on the pressure plate 128, will extend through the vent 135 to provide a visual signal indicating that the reservoir 126 is full.
The auger shaft 118 is mounted for rotation in the pump housing 72. The end of the auger shaft 118 which is opposite the end mounted in the bearing plate 120 is concentrically mounted within a gear box output shaft 140. There is a splined connection between the shaft 140 and the auger shaft 118 so that the former, when it is rotating, drivingly engages the latter. In a known manner, rotation of the auger shaft 118 and, with it, the auger vane 116 within a bore 142 of the pump housing 72 will impart kinetic energy to a fluid. Rotation of the auger vane 116 in a first direction will impart kinetic energy to a fluid in the elbow 98 and thereby move it through the bore 142 of the pump housing 72, through apertures 124 in the bearing plate 120 and into the fluid reservoir 126. Rotation of the auger vane 116 and the shaft 118 in the opposite direction effects an opposite flow, drawing fluid from the fluid reservoir 126 through the apertures 124 in the bearing plate 120, through the bore 142 of the pump housing 72 and into the elbow 98.
The rotational speed of the output shaft 140 is determined in part, by the position of the shift lever 44 which is mounted for rotation about a pivot 143 between a first position illustrated in FIG. 3 and a second position illustrated in phantom lines in FIG. 3. A detente 144 serves to retain the shift lever 44 in the first or second position. In the first position, a shift fork 145 provided on the lever 44 maintains a gear 162 in a first position. When the lever 44 is in the second position, the shift fork 145 maintains the gear 162 in a second position. The function of gear 162 is explained below.
With reference to FIG. 4, the operation of a gear box in gear box housing 64 will be described. The gear box is designed to receive power from a motor output shaft 146. A reduced diameter portion 148 of the shaft 146 is splined to drivingly engage a gear box input shaft 150. A bearing plate 152 is retained in the gear box housing 64 by a snap ring 154. The input shaft 150 is rotatably mounted in a bearing 156 and a seal 158 which are retained in the bearing plate 152 by snap rings 160 and 161. A driving gear 162 is slidably mounted on a reduced diameter portion 164 of the input shaft 150 and retained thereon by a cap 166. The driving gear 162 is shown in a first position in FIG. 4 where it is in driving engagement with a first gear 167 provided on an idler gear assembly 168. A second gear 170 of the idler gear assembly 168 is in driving engagement with a first geared portion 172 of the gear box output shaft 140. The idler gear assembly 168 is mounted for rotation on a shaft 174 and is positioned thereon by spacers 175 and 176 between the bearing plate 152 and a gear box housing plate 178. The gear box output shaft 140 is mounted for rotation within the gear box housing plate 178. The gear box output shaft 140 is rotatably mounted in a bearing 179 and a seal 180 which are retained in the gear box housing plate 178 by the first geared portion 172 of the output shaft 140 and a snap ring 182. A second idler gear assembly 184 includes a gear 186 mounted for rotation on a shaft 187 between spacers 188 and 189. The gear 186 is in driving engagement with a reduced gear portion 190 of the gear box output shaft 140.
The driving gear 162 is mounted on the reduced diameter portion of the gear box input shaft 150 for movement between the first position illustrated for it in FIGS. 3 and 4 and a second position illustrated for it in phantom lines in FIG. 4. In the second position, the driving gear 162 is in driving relationship with the gear 186 which, in turn, is in driving relationship with the reduced gear portion 190 of the gear box output shaft 140. When the driving gear 162 is in the first position, the gear box will transmit rotation of the motor output shaft 146 to the gear box output shaft at a given ratio. When the driving gear 162 is in the second position, rotation of the motor output shaft 146 will be transmitted at a ratio which is lower than the given ratio to the gear box output shaft 146. Shifting of the driving gear 162 between the first and second position can be carried out by pivoting the gear selector lever 44 and the appended shift fork 145 about the pivot 143.
With reference to FIG. 5, circuitry for controlling the components of the dispensing device 10 will now be described.
A motor suitable for incorporation into a device embodying the present invention is indicated schematically at 194. The motor 194 is shown electrically connected to the center poles of switch 40, illustrated in FIG. 5 as a ganged four pole switch. A pair of interior maker bars 196 are illustrated in a central position in the switch 40. The maker bars 196 are adapted to be moved to the right to the extent that they make a circuit between the power cell 50 and the motor 194 so that current of a given polarity is delivered to the motor 194 causing it to rotate in a "forward" direction. Similarly, the maker bars 196 are adapted to be moved from the position illustrated in FIG. 5 to the left thereby making a circuit between the power cell 50 and the motor 194 so that current of a polarity opposite that of the given polarity is delivered to the motor 194 causing it to rotate in a reverse direction. A spring 198 is provided in the switch 40 to give the right-hand side of the switch 40 momentary action, i.e., when released, the maker bars 196 will return to the central position illustrated in FIG. 5 by the action of spring 198. Maker bars 200 are coupled by a non-conducting rod 201 to the maker bars 196 for movement therewith.
The circuitry illustrated in FIG. 5 includes a switch 96 and associated elements which, together, serve a metering function by maintaining the flow of current through the motor 194, even when the maker bars 198 and 200 are in the neutral position, until the motor 194 has completed a cycle. In the embodiment illustrated in FIG. 5, one cycle corresponds with a complete revolution of a wheel 86 which includes a cam 92. The wheel 86 is adapted to be mounted on the shaft of the motor 194. The beginning and end of the cycle occurs each time the cam 92 engages a cam follower 94. Operatively associated with the cam follower 94 is the switch 96 including a pair of internal switches 202. The switches 202 are biased towards a closed position by springs 204. Coaction between the cam 92 and the cam follower 94 at the end of a cycle causes a displacement of the cam follower 94 to the position illustrated for it in FIG. 5. This displacement is transmitted to the switches 202 through means 206 thereby opening the switches 202 as illustrated in FIG. 5. When the wheel 86 is rotated from the position illustrated in FIG. 5, the springs 204 will close the switches 202 to provide a closed circuit between the power cell 50 and the motor 194 through the outside maker bars 200 when they are in the central position or the forward position. The metering function can be disabled through switch 42 by opening it. When the switch 42 is open, current will not be supplied to the motor when the maker bars 200 and 196 are in the central position. With the maker bars 196 and 200 in the central position and switch 42 in the closed position, current will be supplied to the motor 194 until a cycle is completed and the wheel 86 rotates to the position illustrated in FIG. 5. The several modes of operation of the device 10 will now be discussed in connection with charging and discharging lubricant to and from the device 10.
Charging of lubricant 30 (FIG. 1) from a drum 28 into the fluid canister 18 involves bringing the coupling 24 into engagement with the cover 26 of the drum 28. The gear shift lever 44 can be in the first or second position although it is believed that a low ratio gearing is more suitable for use in connection with charging fluid into the lubricant canister 18. The switch 42 can be open or closed but there is no reason for the cycling function to be operable during this mode of operation. Lubricant 30 is then charged into the fluid canister 18 upon movement of the switch 40 to the reversing position. Preferably, lubricant 30 in the lubricant drum 28 is placed under pressure by the spring 33 or by urging the cover 26 towards the bottom 32 of the drum 28. This will create a positive pressure within the lubricant drum 28 thereby urging lubricant 30 to flow through the coupling 24, into and through the conduit 22, through the fitting 20, through the conduit 102 (FIG. 2), the conduit coupling 100, the elbow 98 and into the bore 142 of the pump where rotation of the auger vane 116 will pump the lubricant through apertures 124 in the bearing plate 120 and into the fluid reservoir 126. As the lubricant 30 enters the fluid reservoir 126, it will displace the pressure plate 128 against the force of the spring 132. When the fluid reservoir 126 is full, the switch 40 can be opened to deactivate the motor 194 thereby completing the process of charging the fluid reservoir 126. Alternatively, means including a switch 208 can be provided to cooperate with post 136 to deactivate the motor 194 when the reservoir 126 is full. As shown in FIG. 3, the switch 208 includes a maker bar 210 which is urged by a spring 212 to a closed position. When the reservoir 126 is full, the pressure plate 128 and the post 135 mounted thereon will be displaced from the positions illustrated for them in FIG. 3 to the right until the post 136 engages the maker bar 210 and moves it against the force of the spring 212 to open the switch 208. As shown in FIG. 5, the switch 208 is positioned in the reversing circuit so that when the switch 208 is open, motor 194 will not run in reverse.
Fluid dispensing is commenced by positioning the switch 40 in the forward position thereby causing current to flow from the power cell 50 to the motor 194 which is operatively coupled to the auger shaft 118 through the gearing housed in gear box housing 64. Rotation of the auger shaft 118 and, with it, the auger vane 116, will draw lubricant from the fluid reservoir 126 through the aperture 124 in the bearing plate 120 and through the bore 142 in the pump housing 72. From the pump housing 72, lubricant will then flow through elbow 98, conduit coupling 100, conduit 102 and coupling 20. If the switch 42 is open, lubricant dispensing will cease immediately upon the switch 40 being returned to the central or neutral position. If, on the other hand, the switch 42 is closed, lubricant dispensing will continue after the switch 40 is returned to the central or neutral position and until a cycle is completed and the cam 92 engages the cam follower 94.
Referring now to FIG. 6, a joint compound attachment for the device 10 is indicated generally at 220. The attachment 220 includes a coupling 222 adapted for connection with the fitting 20 or the coupling 24 of the device 10. The coupling 22 is provided at one end of a conduit 224 which is slidably mounted in a handle 226. A set screw 228 is provided in the handle 226 to engage the conduit 224 and prevent it from sliding. Thus, a discharge end 230 of the conduit 224 can be positioned a desired distance from a forward edge 232 of a blade 234. The blade 234 is preferably a resilient blade of the type normally found on putty knives used in connection with the applicant of joint compound to a dry wall joint. Joint compound can be charged into the fluid reservoir 126 and discharged through the joint compound attachment 220 onto the blade 234 for direct application to a wall board joint.
In addition to grease and joint compound, the device 10 is suitable for selectively charging and discharging a variety of other viscous fluids to and from a fluid canister. The foregoing disclosure sets forth the best mode contemplated by the inventors for carrying out the subject invention as of the filing date hereof. It will be apparent to those skilled in the art that the present invention is susceptible of numerous modifications and variations all within the spirit and scope of the appended claims. | A device for dispensing a viscous fluid from and charging a viscous fluid into a canister mounted on a housing of the device is disclosed. The device comprises a reversible auger-type pump including an auger having first and second ends. The first end of the auger is in communication with a nozzle conduit for conducting a viscous fluid between the first end of the auger and a nozzle provided on the nozzle conduit. The second end of the auger is in communication with the canister. The device further includes a motor and associated gearing for connecting the motor to the auger in driving relationship. Power cell means are provided to supply current to the motor. The polarity of the current so supplied is controllable by a switch so that, when current of a given polarity is supplied to the motor, the auger will rotate in a first direction to fill the canister and when the polarity of the current is reversed, the auger will rotate in the opposite direction to dispense from the canister. The device may be equipped with a two-speed gear box to provide additional control over discharge and filling rates in response to a variety of considerations including fluid viscosity. Additionally, the dispenser may be equipped for discharging a metered amount of fluid. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a conductor strip used for making an electrical connection between a printed circuit and a battery. It also relates to a connecting arrangement of such a conductor strip and a circuit board.
2. Description of the Related Art
Recently portable electronic devices including notebook computers, cell phones, etc., have been widely used because of their handiness. For enabling outside use, the cell phone for example operates on a rechargeable battery housed in a battery pack together with other necessary components. The battery pack, readily detachable for exchange of the battery, includes a battery cell and a protection unit connected to the cell for preventing the cell from over-discharging or being overcharged.
FIG. 16 shows some aspects of a conventional protection unit U 0 of the above type. As illustrated, the conventional unit U 0 , used for a rechargeable battery cell 100 , includes a printed circuit board 200 , electronic components 300 mounted on the board 200 , and two conductor strips 400 connected to the battery cell 100 . Each of the conductor strips 400 includes a rectangular connecting portion 400 a and another rectangular connecting portion 400 b . The first connecting portion 400 a is soldered to a pad (not shown) provided on the board 200 , while the second connecting portion 400 b is welded to the cathode or anode (not shown) of the cell 100 . The conductor strip 400 is bent so that the second connecting portion 400 b is perpendicular to the first connecting portion 400 a.
While the conventional conductor strip 400 has a simple configuration and thus can be made easily, it entails the following drawbacks.
As seen from FIG. 16, the first connecting portion 400 a of the conventional strip 400 does not have any holes or gaps in it. Thus, it is impossible to observe the bonding condition of the solder after the applied solder hardens between the connecting portion 400 a and the board 200 . Another problem is that the conductor strip 400 is detached from the board 200 rather easily, due to its simple structure, upon exertion of an upward force on the second portion 400 b.
SUMMARY OF THE INVENTION
The present invention has been proposed under the circumstances described above. It is, therefore, an object of the present invention to provide a conductor strip that can be firmly attached to a printed circuit board and also permits easy inspection of the solder-bonding condition.
According to a first aspect of the present invention, there is provided a conductor strip comprising: a first end portion fixed to a first member; a second end portion fixed to a second member; and a connector arranged between the first end portion and the second end portion. The connector is smaller in size than the first end portion in a width direction perpendicular to another direction connecting the first end portion and the second end portion.
Preferably, the connector may extend from a central part of the first end portion.
Preferably, the conductor strip may further comprise a projection disposed adjacent to the connector, wherein the projection extends from the first end portion toward the second end portion.
Preferably, the connector may comprise two connecting portions spaced from each other in the width direction.
Preferably, a U-shaped slit may be formed in the conductor strip.
Preferably, the first end portion may be soldered to the first member. The second end portion may be welded to the second member.
According to a second aspect of the present invention, there is provided a conductor strip that comprises: a first end portion fixed to a first member; and a second end portion fixed to a second member. The first end portion is formed with a plurality of grooves for improving the bonding strength of solder material applied between the first end portion and the first member.
Preferably, each of the grooves may have a triangular cross section.
Preferably, the plurality of grooves may comprise grooves that perpendicularly intersect each other.
According to a third aspect of the present invention, there is provided an assembly that comprises: a conductor strip that includes a first end portion, a second end portion, and a connector disposed between the first and the second end portions; and a substrate that supports the conductor strip. The connector is smaller in width than the first end portion.
Preferably, the connector may at least partially project from the substrate.
According to a fourth aspect of the present invention, there is provided a method of soldering a conductor strip to a supporting member, wherein the conductor strip is formed with a U-shaped slit. The method comprises the steps of: applying solder paste to the supporting member in a manner such that a solder-void region is formed on the supporting member; positioning the conductor strip on the supporting member; and melting the applied solder paste. The conductor strip is positioned on the supporting member so that the U-shaped slit exposes the solder-void region.
Other features and advantages of the present invention will become apparent from the detailed description given below with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a perspective view showing the principal features of a battery pack incorporating conductor strips provided by the present invention;
FIG. 1B is a plan view showing the principal part of the conductor strip of the present invention;
FIGS. 2 A˜ 2 C illustrate how the conductor strip of the present intention is soldered to a pad;
FIG. 3 is the graph showing the relation between the peel strength and the distance of pull regarding a conventional conductor strip and the conductor strip of the present invention;
FIG. 4A illustrates how the conductor strip of the present invention can be stably attached to the substrate;
FIG. 4B illustrates how the conventional conductor strip is peeled off the substrate upon application of an upward external force;
FIG. 5 shows a possible way to fix the conductor strip of the present invention to the substrate;
FIGS. 6 and 7 are a plan view showing a possible configuration of the slit formed in the conductor strip of the present invention;
FIGS. 8 A˜ 8 C are plan views showing how the conductor strip of a cutout-type can be mounted on the substrate;
FIG. 9 illustrates the advantageous feature of the cutout-type conductor strip;
FIGS. 10 and 11 A˜ 11 B are plan views showing other possible configurations of the cutout-type conductor strip;
FIG. 12 illustrates the advantageous feature of the conductor strip shown in FIGS. 11 A˜ 11 B;
FIGS. 13 A˜ 13 B illustrate a groove-type conductor strip of the present invention;
FIG. 14 illustrates the advantageous feature of the groove-type conductor strip;
FIG. 15 shows a possible modification of the groovetype conductor strip; and
FIG. 16 shows the principal features of a conventional battery pack.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Throughout these figures, similar or identical elements are indicated by the same reference signs.
FIG. 1A shows the principal components of a battery pack utilizing conductor strips provided by the present invention. The battery pack may be used as a power source for a cell phone, notebook computer, etc. As illustrated, the battery pack includes a rechargeable battery cell 1 and a protection unit U 1 . The cell 1 has a side surface la in which a cathode and an anode (not shown) are provided. The protection unit U 1 is connected to the cell 1 for preventing the cell 1 from over-discharging or being overcharged. The unit U 1 includes an insulating substrate 2 , pads 3 formed on the substrate 2 , electronic devices 4 mounted on the substrate 2 , and two conductor strips 5 .
The substrate 2 , made of e.g. a glass-fabric-based epoxy resin, has an upper surface 2 a upon which a wiring pattern (not shown) is formed of cupper. The wiring pattern is connected to the electronic devices 4 and the pads 3 . Each of the conductor strips 5 has a first terminal 5 a connected to the pad 3 and a second terminal 5 b connected to the cathode or anode of the battery cell 1 . The strip 5 may initially be flat as a whole, but be bent to be connected to the cell 1 , as shown in FIG. 1 A.
In the illustrated embodiment, a staple-shaped (U-shaped) slit 6 (K=0.4 mm) is formed in the first terminal 5 a of each strip 5 , whereby the strip 5 is provided, as shown in FIG. 1B, with two connecting portions 5 c and a rectangular projection 5 d (H=0.5 mm) disposed between the connecting portions 5 c . The width W 1 of each connecting portion 5 c is smaller than the width W 2 (=2.5 mm) of the conductor strip 5 . The technical significances of the slit 6 will be described later.
The first terminal 5 a of each strip 5 is soldered to the pad 3 in the following manner. First, as shown in FIG. 2A, solder paste is applied to the pad 3 to form a narrow paste land (first land) 7 a and a larger, rectangular paste land (second land) 7 b spaced from the first land 7 a by a prescribed short distance. A linear region 8 is between the two lands 7 a and 7 b , which is left uncovered by the solder paste. The application of the solder paste may be performed by using a mask formed with openings corresponding to the first and the second lands 7 a , 7 b . The mask is laid on the pad 3 , and then solder paste is spread over the mask with a squeegee.
As shown in FIG. 2B, the conductor strip 5 is placed on the pad 3 so that a part of the solder-void region 8 is observed through the slit 6 . The strip 5 may be automatically set into place with the use of a suction collet. Then, the substrate 2 together with the strips 5 (the “strip-substrate assembly” below) is heated in a furnace to melt the applied solder paste 7 . The molten solder material is spread over the pad 3 under the weight of the conductive strip 5 . Then, the strip-substrate assembly is taken out of the furnace to allow the solder material to cool. Subsequently, the solder solidifies, to secure the strip 5 to the pad 3 .
For fixing the strip 5 to the pad 3 properly, the molten solder needs to be spread uniformly between the first terminal 5 a and the pad 3 . When this ideal condition is attained, the first terminal 5 a as a whole will be fixed to the pad 3 after the strip-substrate assembly is brought out from the furnace.
Advantageously, the slit 6 formed in the first terminal 5 a enables ready inspection of whether the soldering has been performed properly or not. Specifically, when the molten solder is spread uniformly between the first terminal 5 a and the pad 3 , the linear region 8 will disappear. When the solder has failed to be spread properly, on the other hand, the linear region 8 will remain partially or entirely. In the illustrate embodiment, the remaining or disappearing of the region 8 can be simply observed through the slit 6 .
In addition to the above advantage, the slit 6 contributes to the improvement in peel strength of the conductor strip 5 . Referring to FIG. 3, the graph shows the relation between the ‘peel strength’ and the ‘distance of pull’ (“PS-DP relation” below) with respect to the conventional strip 400 (FIG. 16) and the strip 5 of the present invention. The ‘distance of pull’ indicates how much the second terminal 5 b or 400 b is pulled upward (see FIGS. 4 A and 4 B). The graph of FIG. 3 shows that the maximum peel strength Cmax of the conventional strip 400 is about 20 N(newton), whereas the maximum peel strength Pmax of the strip 5 of the present invention is nearly 40 N. The reason why the peel strength Pmax of the strip 5 is greater than the peel strength Cmax of the conventional strip 400 is as follows. As seen from FIG. 16, the first terminal 400 a of the conventional strip 400 is a simple rectangular plate provided with no countermeasure to resist the peeling force. Thus, as the graph of FIG. 3 shows, the peel strength of the conventional strip is relatively low after the maximum peel strength Cmax is attained.
The strip 5 of the present invention exhibits generally the same “PS-DP relation” as that of the conventional strip 400 when the distance of pull is about 0˜0.6 mm (see FIG. 3 ). Then, when the distance of pull is about 0.6˜1.6 mm (the range Sw in FIG. 3 ), the strip 5 is peeled off the substrate more easily than the conventional strip 400 . The strip 5 exhibits the weaker peel strength because the peeling is proceeding with respect to the relatively narrow connecting portions 5 c . Thereafter, the peel strength of the strip 5 becomes greater than that of the conventional strip 400 . This is because the projection 5 d of the strip 5 clings to the substrate 2 , as shown in FIG. 4A, thereby serving as an additional resisting portion against the peeling force F.
In the above-described embodiment, the strip 5 is supported by the substrate 2 so that the slit 6 as a whole is located on the substrate 2 . The present invention is not limited to this, and the slit 6 may partially be off the substrate 2 , as shown in FIG. 5 . Further, the strip 6 may not have the staple-like, angular configuration, but have a smooth, arcuate (U-shaped) form, as shown in FIG. 6 . Still further, the conductor strip 5 may be formed with two slits 6 , as shown in FIG. 7 . In the illustrated example, each of the two end portions of the strip 5 is formed with one slit 6 and connected to a substrate 2 or 2 ′.
FIG. 8A shows another possible configuration of the strip 5 . In this embodiment, the first terminal 5 a is formed with two rectangular cutouts spaced across a relatively narrow connecting portion 5 c . With such an arrangement again, the remaining or disappearing of the linear region 8 (FIG. 2A) is observed through the rectangular cutouts. Thus, the quality inspection of the reflow soldering is readily performed. In the illustrated example, d 1 may be 3.0 mm, d 2 may be 3.0 mm, and d 3 may be 0.25˜0.75 mm.
If the above inspection is not required, the strip 5 may be positioned so that the connecting portion 5 c projects from the edge of the substrate 2 entirely as shown in FIG. 8B or partially as shown in FIG. 8 C. The position of FIG. 8C is more advantageous to performing self-alignment of the strip 5 than that of FIG. 8, since the molten solder 7 can enclose the connecting portion of the strip 5 more thoroughly.
Like the slit-forming arrangement described above, the cutout-forming arrangements of FIGS. 8 A˜ 8 C contribute to the improvement of the peel strength of the strip 5 . Referring to FIG. 9, when an upward external force F is exerted on the second terminal 5 b , the first terminal 5 a is about to be pulled upward. Differing from the prior art case (FIG. 16 ), the effect of the pulling force acts on the first terminal 5 a via the relatively narrow connecting portion 5 c . As a result, part of the external force F may be directed in the normal direction to the substrate surface 2 a , which is the most effective direction for peeling off the first terminal 5 a , while the other part of the external force F will act in slant directions to the substrate surface 2 a , which are less effective peeling-off directions. Consequently, a greater external force is required to peel off the strip 5 than in the case of the conventional strip 400 . The cutout formed in the strip 5 may be semi-circular, as shown in FIG. 10 .
According to the present invention, the first terminal 5 a of the strip 5 shown in FIG. 8A may be provided with two protrusions 5 e that extend from the first terminal 5 a toward the second terminal 5 b , as shown in FIG. 11 A. With such an arrangement, the first terminal 5 a is kept attached to the pad 3 more firmly than when only the narrow connecting portion 5 c is provided between the first and the second terminals 5 a , 5 b . The reason is as follows. Referring to FIG. 12, when the upward external force F acts on the second terminal 5 b , the pulling force is transmitted to the first terminal 5 a via the narrower connecting portion 5 c . Thus, as in the case described with reference to FIG. 9, the first terminal 5 a is attached to the pad 3 more strongly than is conventionally possible. Further, according to the arrangement of FIG. 12, the projections 5 e remain to be attached to the substrate 2 even after the connecting portion 5 c is peeled off. Accordingly, the binding strength between the first terminal 5 a and the substrate 2 is rendered much stronger. As shown in FIG. 11B, the connecting portion 5 c may partially protrude from the edge of the substrate 2 .
According to another embodiment of the present invention, a plurality of grooves 9 may be formed on the bottom side of the first terminal 5 a of each conductor strip 5 , as shown in FIGS. 13A and 13B. In the illustrated example, each groove 9 extends widthways of the strip 5 and has a triangular cross section (see FIG. 14 ). In this arrangement, the molten solder material 7 fills the grooves 9 , as shown in FIG. 14, and then hardens.
The above groove arrangement is advantageous to achieving reliable fixation of the strip 5 to the substrate 2 . The reason is as follows. Referring to FIG. 14, the triangular configuration of each groove 9 is defined by a first slant surface 9 a and a second slant surface 9 b . When an upward external force F is exerted on the second terminal 5 b of the strip 5 , the second slant surface 9 b of the rightmost groove 9 may be peeled off the solder material 7 rather readily because the peeling force f 1 acts in a direction generally perpendicular to the second slant surface 9 b . After the second surface 9 b is detached, a peeling force f 2 is exerted on the first slant surface 9 a.
The acting direction of this force, however, is generally parallel to the first slant surface 9 a , as seen from FIG. 14 . Since the bonding force of the solder 7 is strong in this direction, the first terminal 5 a can remain to be attached to the substrate 2 against a great external force.
As shown in FIG. 15, the conductor strip 5 may additionally be formed with a plurality of grooves 10 extending longitudinally of the strip 5 . With such an arrangement, the strip 5 can remain to be attached to the substrate 2 upon application of a rather great torsional force f 3 about the longitudinal axis La.
According to the present. invention, the grooves 9 may not be straight or have a triangular cross section.
The grooves 9 and/or 10 may be formed in the conductor strip shown in FIGS. 1A, 6 , 7 , 8 A˜ 8 C, 10 or 11 A˜ 11 B.
The present invention being thus described, it is obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to those skilled in the art are intended to be included within the scope of the following claims. | A conductor strip includes a first end portion soldered to a printed circuit board, and a second end portion welded to a rechargeable battery. The conductor strip also includes a connecting portion disposed between the first and the second end portions. The connecting portion has a smaller width than that of the first end portion so that the peeling force acting on the first end portion is alleviated. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to an exhaust emission control device of an internal combustion engine.
[0003] 2. Description of the Related Art
[0004] A three-way catalyst is widely used as the exhaust emission purification catalyst of an internal combustion engine. However, current three-way catalyst has a significantly low efficiency when the temperature is low. For this, various studies are being made to exploit catalysts which are highly active even at low temperatures to thereby decrease emission when the engine starts in low temperature conditions.
[0005] U.S. Pat. No. 5,776,417 discloses an exhaust emission control device using a catalyst which is highly active at relatively low temperature.
SUMMARY OF THE INVENTION
[0006] The CO oxidation catalyst used in the art described above is improved in activity at low temperatures, however, it is needless to say that it has higher activity at high temperatures. If a rise in temperature is accelerated, the efficiency of engine emission purification just after the engine starts gets improved. In view of this, the inventors of the present invention have made earnest studies concerning unused energy included in exhaust gas which energy is effective to accelerate a rise in temperature.
[0007] In the above art, a low temperature light-off CO oxidation catalyst is used. Moreover, a HC trap is arranged upstream of the CO oxidation catalyst and a H 2 O trap is further arranged upstream of the HC trap because the low temperature activity of the CO oxidation catalyst is disturbed by the presence of H 2 O and HC.
[0008] When the H 2 O trap adsorbs H 2 O contained in the exhaust gas from an engine, heat of adsorption and heat of condensation are emitted. This makes it possible to build up such a hypothesis that a rise in the temperature of the catalyst can be accelerated if these heats are utilized. The inventors have found that these heats are consumed to raise the temperature of the HC trap arranged downstream of the engine and an exhaust pipe and therefore make almost no contribution to a rise in the temperature of the catalyst in the above art.
[0009] The inventors carried out experiments on the effect of the heat generated with the trap of H 2 O. A comparison was made between the case of arranging a HC trap next to a H 2 O trap in the same manner as in the above art and the case of arranging a H 2 O trap next to a HC trap. As a result, it was confirmed that the temperature of the gas flowing in the CO oxidation catalyst was higher and a rise in the temperature and activation of the oxidation catalyst were more accelerated in the latter case.
[0010] The present invention has been made in view of the above experimental results and it is an object of the present invention to attain early activation of a CO oxidation catalyst by removing H 2 O which is a component disturbing the activity of the catalyst and by making efficient use of the effect of raising temperature due to the adsorption heat and condensation heat of H 2 O when the low temperature light-off CO oxidation catalyst is used.
[0011] An exhaust emission control device according to the present invention comprises a CO oxidation catalyst having low temperature light-off characteristics and a H 2 O trap arranged adjacent to and upstream of the CO oxidation catalyst.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 is a block diagram of an exhaust emission control device of an internal combustion engine according to the first embodiment of the present invention.
[0013] [0013]FIG. 2 is a flow chart showing the control of the exhaust emission control device according to the first embodiment.
[0014] [0014]FIG. 3A is a block diagram according to a comparative example wherein a HC trap is arranged downstream of a H 2 O trap.
[0015] [0015]FIG. 3B is a block diagram according to the present invention wherein a H 2 O trap is arranged downstream of a HC trap.
[0016] [0016]FIG. 3C is a graph showing the relationship between the structures of a catalyst and a trap in an exhaust emission control device and the time of the activation of the catalyst.
[0017] [0017]FIG. 4 is a block diagram of an exhaust emission control device of an internal combustion engine according to the second embodiment of the present invention.
[0018] [0018]FIG. 5 is a view showing a constituent example 1 of an underfloor catalyst according to the second embodiment.
[0019] [0019]FIG. 6 is a view showing a constituent example 2 of an underfloor catalyst according to the second embodiment.
[0020] [0020]FIG. 7A is a view showing an example A in which a H 2 O trap is arranged as the upper layer and a CO oxidation catalyst is arranged as the lower layer in the constituent example 2 of the underfloor catalyst according to the second embodiment.
[0021] [0021]FIG. 7B is a view showing an example B in which a CO oxidation catalyst is arranged as the upper layer and a H 2 O trap is arranged as the lower layer in the constituent example 2 of the underfloor catalyst according to the second embodiment.
[0022] [0022]FIG. 7C is a view showing an example C in which a H 2 O trap and a CO oxidation catalyst are mixed with each other and supported in the constituent example 2 of the underfloor catalyst according to the second embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] A first embodiment of the present invention will be explained with reference to FIG. 1. An exhaust pipe 2 from an engine body 1 is provided with an exhaust emission purification catalyst 3 . Further, an underfloor catalyst system containing a CO oxidation catalyst 6 which has low light-off temperature properties is disposed downstream of the exhaust emission purification catalyst 3 .
[0024] The underfloor catalyst system CS has a structure in which a HC trap 4 , a H 2 O trap 5 and the CO oxidation catalyst 6 are arranged in this order from the upstream side. Here, the H 2 O trap 5 is disposed not only at a position adjacent to and upstream of the CO oxidation catalyst 6 but also close to just the upstream side of the CO oxidation catalyst 6 . A temperature sensor 7 is attached to the CO oxidation catalyst 6 .
[0025] A secondary air introduction pipe 9 extending from an air pump 8 is connected between the HC trap 4 and the H 2 O trap 5 . Here, the introduced secondary air is used to control a reaction running on the CO oxidation catalyst.
[0026] The above exhaust catalyst 3 is a three-way catalyst obtained by coating a honeycomb support with alumina carrying at least one component selected from noble metals such as platinum (Pt), palladium (Pd) and rhodium (Rh) and has the properties that it purifies HC, CO and NOx at the same time when the exhaust air/fuel ratio agrees with the theoretical air/fuel ratio and HC and CO by an oxidation reaction when excessive air is present.
[0027] As the above HC trap 4 , a material obtained by coating a honeycomb support with a zeolite (for example, b-zeolite, A-type zeolite, Y-type zeolite, X-type zeolite, ZSM-5, USY, mordenite and ferrierite) is used.
[0028] As the above H 2 O trap 5 , a material obtained by coating a honeycomb support with a zeolite (for example, b-zeolite, A-type (3A, 4A, 5A and 13A) zeolite, Y-type zeolite, X-type zeolite, ZSM-5, USY, mordenite and ferrierite) is used. The A-type zeolite (particularly 5A) is particularly preferred.
[0029] As the above CO oxidation catalyst 6 , a three-way catalyst obtained by coating a honeycomb support with ceria carrying at least one component selected from noble metals such as platinum (Pt), palladium (Pd) and rhodium (Rh). However, any material having the properties (low temperature light-off properties) enabling highly efficient conversion of CO since when the temperature is low may be used. Such catalyst is called “low temperature light-off catalyst”, wherein “light-off” means that the catalyst starts a reasonable conversion efficiency.
[0030] The above secondary air introduction pipe 9 may be disposed upstream of the CO oxidation catalyst 6 and downstream of the exhaust emission purification catalyst 3 . However, if the secondary air introduction pipe 9 is disposed upstream of the HC trap 4 , the SB of the HC trap 4 increases to thereby promote the dissociation of HC whereas if it is disposed downstream of the H 2 O trap, H 2 O which is a component disturbing activity of the catalyst in the secondary air flows into the CO oxidation catalyst 6 . Therefore, secondary air introduction pipe 9 is preferably arranged between the HC trap 4 and the H 2 O trap 5 .
[0031] The control of the operation in this embodiment is carried out according to a flowchart of FIG. 2. This routine is executed, for example, every one second.
[0032] In step S 1 , the start temperature T start of the CO oxidation catalyst which temperature is detected by a CO oxidation catalyst temperature sensor 7 and stored when the engine starts is read to judge whether the temperature T start is less than a predetermined temperature a (for example, 200° C.) or not.
[0033] If the temperature T start <a, the CO oxidation catalyst 6 is judged to be still inactivated and then the process is forwarded to step S 2 .
[0034] Instep S 2 , the present temperature T cat of the CO oxidation catalyst 6 which temperature is detected by the CO oxidation catalyst temperature sensor 7 is read to judge whether or not the temperature T cat is made to be above a predetermined temperature c (for example, 600° C.) by treatment in step S 3 as will be explained later.
[0035] If the temperature T start <c, the CO oxidation catalyst 6 is judged to be still inactivated and then the process is forwarded to step S 3 .
[0036] In step S 3 , in order to introduce a large amount of CO and air into the CO oxidation catalyst 6 , a target fuel/air ratio TFBYA under the control of injection quantity is set to a predetermined fuel/air ratio (for example, 1.5) while the air pump 8 is allowed to operate, thereby supplying secondary air to set the ratio (Cat-In TFBYA) of exhaust fuel/air flowed into the CO oxidation catalyst 6 to a predetermined fuel/air ratio b (for example, 0.9) by the control of the secondary air.
[0037] Here, the target fuel/air ratio TFBYA is the reciprocal of excess air ratio ? and takes 1 at the theoretical fuel/air ratio, a number more than 1 when excess fuel is present and a number less than 1 when excess air is present. When the target fuel/air ratio TFBYA is set, an injection quantity T p is set by multiplying the basic injection quantity (K-Q a /N e ; K is constant) corresponding to the theoretical air/fuel ratio and determined by an intake air flow Q a and an engine speed N e by the target fuel/air ratio TFBYA. Based on the injection quantity T p , a fuel injection valve on the side of the engine 1 is driven to inject fuel.
[0038] Moreover, the amount of secondary air is set by the injection quantity T p , the intake air flow Q a , the predetermined fuel/air ratio R and the predetermined fuel/air ratio b. The predetermined fuel/air ratio R and the predetermined fuel/air ratio b are found in advance by experiments.
[0039] Such a treatment in step S 3 allows an oxidation reaction to proceed between a large amount of CO and air to promote a rise in the temperature of the CO oxidation catalyst 6 due to reaction heat. If T act =c, the CO oxidation catalyst 6 is judged to be in an activated condition based on the judgment in step S 2 in the routine on and after the next time and then the process is forwarded to step S 4 . The predetermined temperature c is found in advance by experiments.
[0040] In step S 4 , the target fuel/air ratio TFBYA is returned to a normal and also the air pump 8 is terminated to stop supplying the secondary air whereby the engine control is returned to normal.
[0041] On the other hand, when T start =a in the judgment of step S 1 , the CO oxidation catalyst 6 is judged to be in an activated condition and then the process is forwarded to step S 4 . In step S 4 , the target fuel/air ratio TFBYA is set to normal and secondary air is not supplied by the air pump 8 to bring the system under normal engine control. The predetermined temperature a is found in advance by experiments. It is to be noted that the following method may be adopted instep S 1 . Specifically, the temperature of engine water when the engine starts is detected instead of the temperature of the CO oxidation catalyst when the engine starts and based on this result, the decision is made in the same manner as above.
[0042] [0042]FIG. 3C shows the results of experiments for car evaluation when the constitution A (comparative example) and the constitution B (present invention) are used in an underfloor catalyst system shown in FIG. 1.
[0043] A rise in the temperature of the inlet for the CO oxidation catalyst when the engine starts at low temperatures is more significant in the case of the constitution B (present invention) in which the HC trap, the H 2 O trap and the CO oxidation catalyst are arranged in this order from the upstream side to dispose the H 2 O trap just upstream of the CO oxidation catalyst than in the case of the constitution A (comparative example) in which the H 2 O trap, the HC trap and the CO oxidation catalyst are arranged in this order from the upstream side. Therefore, the CO oxidation catalyst is early activated in the case of the present invention. This is because the adsorption heat and condensation heat of H 2 O in the H 2 O trap contribute efficiently to a rise in the exhaust gas temperature. In the case of the constitution A, because these generated heats are consumed for heating of the exhaust pipe and for heat radiation from the exhaust pipe, they do not contribute efficiently to a rise in the exhaust gas temperature.
[0044] Next, a second embodiment of the present invention will be explained.
[0045] [0045]FIG. 4 shows a block diagram of an engine exhaust system in this embodiment. The same elements as those in FIG. 1 are represented by the same reference numerals.
[0046] An exhaust pipe 2 from an engine body 1 is provided with an exhaust emission purification catalyst 3 . An underfloor catalyst 10 including a CO oxidation catalyst which has low light-off temperature characteristics and a H 2 O trap is disposed downstream of the exhaust emission purification catalyst.
[0047] A secondary air introduction pipe 9 extending from an air pump 8 is connected between the exhaust emission purification catalyst 3 and the underfloor catalyst 10 . The secondary air introduced here is used to control a reaction in the CO oxidation catalyst 6 .
[0048] The air/fuel ratio and the amount of the secondary air are controlled based on signals from a temperature sensor 7 attached to the underfloor catalyst 10 according to a flowchart of FIG. 2 described above.
[0049] The constituent examples of the underfloor catalyst 10 are shown in FIG. 5, FIG. 6 and FIGS. 7A to 7 C.
[0050] The constituent example of FIG. 6 is obtained by allowing the CO oxidation catalyst and the H 2 O trap to be coated on the same honeycomb support by separately applying the both layer-wise or mixing the both. Because the both are disposed very close to each other, the effect of a rise in temperature due to the adsorption heat of H 2 O can be utilized in an efficient manner.
[0051] In three types of constitution shown in FIGS. 7A to 7 C, there is no large difference in temperature rise properties. However, a structure in which the H 2 O trap is arranged as the upper layer as shown in FIG. 7A is desirable to efficiently remove H 2 O which is a component disturbing the activity of the catalyst.
[0052] It is to be noted that although the HC trap is omitted in this embodiment, it may be disposed downstream of the exhaust emission purification catalyst 3 and the secondary air introduction pipe 9 and upstream of the underfloor catalyst 10 containing the CO oxidation catalyst and the H 2 O trap.
[0053] The contents of Japanese Patent Application No. 2000-337,073 (filed Nov. 6, 2000) are incorporated herein by reference.
[0054] Although the invention has been described above by reference to certain embodiments of the invention, the invention is not limited to the embodiments described above. Modifications and variations of the embodiments described above will occur to those skilled in the art, in light of the above teachings. | In an exhaust path, a HC trapping material which traps HC contained in exhaust gas temporarily, a H 2 O trap which traps H 2 O contained in exhaust gas and a CO oxidation catalyst are arranged in this order from the upstream side, wherein the H 2 O trap is disposed just upstream of and close to the CO oxidation catalyst. H 2 O and HC which are components disturbing the activity of the CO oxidation catalyst can be removed efficiently and the adsorption heat and condensation heat of H 2 O can be efficiently utilized to raise the temperature of the CO oxidation catalyst so that early activation of the CO oxidation catalyst is accomplished just after an engine starts. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process and an equipment for the reactivation of spent activated carbon onto which pollutants were adsorbed.
2. Description of the Related Art
Activated carbon is widely used in the purification of contaminated water and air because of its excellent capabilities of adsorbing various inorganic or organic substances.
After being used, the activated carbon is generally reactivated. The reactivation processes allow the activated carbon to recover its adsorption capacities and thereby, the reactivated carbon is re-used in the adsorption process. However, the current reactivation methods generally demand very high costs and thus, limit adopting the activated carbon-utilizing purification process.
There are various conventional methods for the reactivation of the used carbon, for example, thermal reactivation, solvent extraction or wet oxidation, etc., depending on the nature of the pollutants adsorbed on the activated carbon.
As being the most available reactivation method, the thermal reactivation requires the reactivation furnace to be processed at high temperatures of 900° C. to 1000° C. similar to that used in the production of the activated carbon. Therefore, the construction and maintenance of the thermal reactor demands high costs.
The existing solvent extraction method is disadvantageous because the adsorption recovery efficiency of the reactivated carbon is low and there is a possibility that a portion of the harmful solvent used remains in the reactivated carbon.
The wet oxidation method is deficient in the degradation or desorption of the pollutants irreversibly adsorbed on the activated carbon.
Therefore, there has been a need for new methods and/or equipment permitting the reactivation of the spent activated carbon, which can highly recover the adsorption capacities of the activated carbon and which also are less costlyto use and operate.
SUMMARY OF THE INVENTION
The present invention provides a method of the reactivation of spent activated carbon onto which pollutants were adsorbed, which comprises a first step of subjecting the used activated carbon to a mixed solution including ethanol, sodium hydroxide solution and water to effectuate the desorption of the pollutants adsorbed on the activated carbon.
In addition, the present invention provides equipment for reactivating the spent activated carbon onto which the pollutants were adsorbed, which comprises (A) a mixing tank for mixing given amounts of water, ethanol and sodium hydroxide solution which are supplied from respective receptacles thereof; (B) a reactivating reactor for receiving the mixed solution from the mixing tank and subjecting the spent activated carbon filled therein to the mixed solution to effectuate the desorption of the pollutants adsorbed on the spent activated carbon, wherein the reactivation reactor is provided with means for regulating temperature of the mixed solution; and (C) a storage tank for receiving the reactivated carbon.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a flow chart illustrating a process for the reactivation of activated carbon according to the present invention.
FIG. 2 shows equipment for the reactivation of activated carbon according to the present invention.
FIG. 3 shows a bar graph of phenol adsorption recovery of reactivated carbons under conditions 1 to 4 according to the present invention.
FIG. 4 shows a bar graphs of humic substances adsorption recovery of reactivated carbons under conditions 1 to 4 according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
According to the present invention, ethanol is preferably used in the amount of 10% to 50% based on a mixed solution of ethanol, sodium hydroxide solution, and water, and the sodium hydroxide solution is used in the amount of 1% to 4% based on the mixed solution.
In a further preferred embodiment of the present invention, the mixed solution of ethanol, sodium hydroxide solution, and water is heated to a temperature in a range from ambient to 100° . In direct connection, since the desorption of the pollutants adsorbed on the activated carbon proceeds at a lowertemperature than in other methods, the present process and equipment advantageously require a lower expenditure of energy and more convenient operation and maintenance.
In a still further preferred embodiment, the desorption of the pollutants adsorbed on the activated carbon in the mixed solution of ethanol, sodium hydroxide solution and water proceeds for a period of 6 to 24 hours.
The reactivation process and the equipment of the present invention can be applied to drinking water and wastewater treatment plants, air pollution-preventing equipments, etc. It is especially useful in the purification of drinking water, since solvents used by the present invention, i.e., ethanol and sodium hydroxide are food grade and not harmful.
The reactivation process according to the present invention will be described in detail in reference to the accompanying drawings.
FIG. 1 is a flow chart illustrating the physico-chemical process according to the present invention for the reactivation of spent activated carbon onto which pollutants were adsorbed. As shown, 1% to 4% of NaOH, 10% to 50% of ethanol and water are mixed in a mixing tank and the mixed solution in the mixing tank is circulated into a reactivation (step 100 ) reactor filled with the spent activated carbon to be reactivated. The reactivation tank is tightly closed and heated to a temperature in the range between normal temperature and 100° C. for 6 to 24 hours (step 110 ). As a result, the pollutants are desorbed from the activated carbon. The waste liquid formed by such a desorption reaction in the reactivation reactor is transported via a receptacle into a distiller. Ethanol is recovered from the waste liquid in the distiller by evaporation, followed by condensation (step 120 ). The recovered ethanol is circulated into the mixing tank and recycled for the next reactivation process. Meanwhile, after the waste liquid formed by the desorption reaction in the reactivation reactor exits to the receptacle, the activated carbon in the reactivation reactor is in situ washed (rinsed) with tap water in order to remove the residual ethanol and NaOH from the activated carbon (step 130 ). Additionally, ethanol in the washing water is also recovered for re-use. As a final procedure, the reactivated carbon is transported to a storage tank or an adsorber for re-use (step 140 ).
FIG. 2 shows equipment for the reactivation of the activated carbon according to the present invention. This figure illustrates three receptacles 1 , 2 and 3 for containing water, ethanol and NaOH solution, respectively. The respective solvents are circulated by pumps P 1 , P 2 and P 3 into a mixing tank 4 . After the solvents are mixed in the mixing tank 4 , the mixed solution is circulated by a pump P 4 into a reactivation reactor 5 filled with the spent activated carbon onto which pollutants were adsorbed. The temperature in the reactivation reactor 5 is increased by the heat supplied from a boiler 6 and/or a heater 12 , the heater 12 being equipped within the reactivation reactor 5 . After the completion of the desorption, the resulting waste liquid in the reactivation reactor 5 is circulated by a pump P 6 into a receptacle 8 and then, the activated carbon in the reactivation reactor 5 is washed with tap water while the washing water flows via valves to a distiller 9 . The washed activated carbon in the reactivation reactor 5 is carried to a storage tank 7 . The waste liquid in the distiller 9 is heated by the boiler 6 to evaporate the ethanol. The evaporated ethanol is condensed and collected. The ethanol in the storage tank 11 is circulated by a pump P 7 into the mixing tank 4 for re-use.
The following examples are given merely as illustrations of the present invention and demonstration of the preferred embodiments of the present invention, and are not to be considered as limiting.
EXAMPLES
The activated carbon used for water treatment for 1 year and 4 months was subjected to the reactivation process of the present invention. 108 cases in the desorption process were established by varying the amount of ethanol between 10% and 50%, the amount of NaOH between 1% and 4% and the condition of ambient temperature to 100° C., and UV254 absorbance was measured on the waste liquid formed through the desorption process. The results are summarized as follows.
When the desorption was carried out at the ambient temperature, the UV absorbance of the extracted solution by the present invention is 8,000 to 30,000 times as high as that from tap water. For the desorption temperature of 60° C., the extracted solution by the present invention increases the UV254 absorbance by 15,000 to 50,000 times of the tap water treated. For the desorption temperature of 100° C., the extracted solution by the present invention increased the UV254 absorbance by 16,000 to 80,000 times of the tap water treated.
Particularly, when the desorption was performed for 12 to 24 hours at 80° C. to 100° C., the mixed solution consisting of 20-40% of ethanol, 2-4% of NaOH and water increased the UV254 absorbance by 50,000 times or more as compared to tap water.
It is expected that such unexpected results are derived from the synergistic effects occurring due to the combination of the selective solvents and temperature for the desorption according to the present invention.
FIGS. 3 and 4 are bar graphs of the recovery of adsorption capacities of the activated carbon which was reactivated by the reactivation process of the present invention. The adsorption capacity recovery was evaluated by adsorbing phenol (FIG. 3) or humic substance (FIG. 4) on the reactivated carbon for 48 hours.
As shown in FIG. 3, typically, the recovery of phenol adsorption by the reactivated carbon according to the present invention ranges from 80% to 120%. Especially, when 20% of ethanol, 4.0% of NaOH and temperature of 100° C. are utilized for the desorption, the adsorption recovery amounts to approximately 120% as presented in bars 1 and 2 . Bars 1 and 2 indicate the results obtained by using the reactivated carbon in the amounts of 0.5 g and 1.5 g, respectively. Bars 3 and 4 indicate the results obtained by utilizing 20% of ethanol, 4.0% of NaOH and temperature of 200° C. as the desorption conditions while using 0.3 g and 1.0 g of the reactivated carbon, respectively. As shown in FIG. 4, the humic substance adsorption recovery of the reactivated carbon according to the present invention is from 80% to 100%. Generally, the humic substance adsorption recovery is comparatively lower than the phenol adsorption recovery but it is still acceptable considering the lower cost. Bars 1 and 2 indicate the results obtained by utilizing 20% of ethanol, 4.0% of NaOH and temperature of 100° C. as the desorption conditions while using 0.5 g and 1.5 g of the reactivated carbon, respectively. Bars 3 and 4 indicate the results obtained by utilizing 20% of ethanol, 4.0% of NaOH and temperature of 200° C. as the desorption conditions while using 0.3 g and 1.0 g of the reactivated carbon, respectively.
The removal of the humic substance by the reactivated carbon was determined by a column test. The reactivated carbon was formed by subjecting the activated carbon used in a water treatment plant for 16 months in the equipment depicted in FIG. 2 for 12 hours while using the mixed solution of 20% of ethanol, 4% of NaOH and water and the temperature of 100° C. as the desorption conditions. The column test revealed that the humic substance removal efficiency of the reactivated carbon of the present invention corresponds to about 90% as compared to that obtained by fresh activated carbon. This result indicates that the reactivation process of the present invention is comparable to the prior thermal reactivation in terms of its humic substance removal.
Iodine adsorption was tested for the reactivated carbon of the present invention. This activated carbon has been used in a water treatment plant for 16 months in the equipment of the present invention for 24 hours while using the mixed solution of 20% of ethanol, 2% of NaOH and water and the temperature of 100° C. as the desorption conditions. This test revealed that the iodine number of the reactivated carbon ranges to 80%-90% of the fresh activated carbon. Table I below shows the iodine number of the reactivated and fresh carbon. The iodine number was evaluated by the Korean Granular Activated Carbon Test Method KSM 1802 which is the same as the AWWA procedure.
TABLE I
Active Carbon Types
Iodine Adsorption (mg/g)
Regenerated by the present process
1023
Fresh
1212
Korean Standard Rating 1
1,100 or more
Korean Standard Rating 2
1,000 to 1,100
Korean Standard Rating 3
900 to 1,000
As can be shown in Table I, the reactivated carbon of the present invention recovered the iodine number significantly, and therefore, it is concluded that the process for the reactivation of the spent activated carbon according to the present invention can be successfully applied to the water and air purification industries. | A process and a set of equipment for reactivating spent activated carbon onto which pollutants were adsorbed. The present process comprises subjecting the activated carbon to be reactivated in a mixed solution consisting of ethanol, sodium hydroxide solution and water to effectuate the desorption of the pollutants adsorbed on the activated carbon. The equipment includes (A) a mixing tank for mixing given amounts of water, ethanol and sodium hydroxide solution which are supplied from the respective receptacles thereof; (B) a reactivation reactor for receiving the mixed solution from the mixing tank and subjecting the spent activated carbon filled therein to the mixed solution to effect the desorption of the pollutants adsorbed on the spent activated carbon, wherein the reactivation reactor includes a unit for regulating temperature of the mixed solution; and (C) a storage tank for receiving the reactivated carbon. | 1 |
SPECIFICATION
The invention relates to a neurostimulator.
Treatment with a neurostimulator, particularly if drug therapy is insufficient and surgical intervention is connected with a high risk, brings about results in patients who, due to impairments in peripheral blood circulation, suffer from night pain. Reflex generated pain to be eliminated with spinal cord stimulation occurs in the so-called Head's zones which receive their sensory fibers from the same spinal chord segment as the diseased organs. Electrostimulation is to be felt in the Head's zones. Stimulation of nerve functions is employed not only for the suppression of pain but also for the stimulation of increased blood circulation in the diseased organs.
One problem of implanted devices is the gradually exhausted energy supply. Even with long-term batteries, such devices are able to operate with pulsed or burst-shaped stimulation only for so long. Thus, the prior art devices are unable to operate without an external energy source.
A neurostimulator is known in the art which includes an external transmitter and an implantable receiver as well as an antenna that can be glued to the skin. During the post-operative phase, pain is reduced either by continuous wave stimulation or by stimulation bursts, with the amplitude and the duration of the stimulation pulses being adjustable through the transmitter in the patient device. For example, pain reduction decreases gradually as the patient becomes used to the device so that the dosage must be increased. It is also customary for the patient to decide how long the pulses are to continue. Thus, night pain again and again interrupts the patient's rest and it would thus be desirable for stimulation to take place automatically, without interference and overdoses.
An implantable neurostimulator is known which is equipped with a programmable logic unit disposed within the implantable receiver to generate stimulation pulses and with an implantable multiple electrode. For stimulation, the neurostimulator cooperates with a device outside the patient's body which, at greater intervals, can selectively be brought in connection with a programming device (M. Schaldach, H. Hutten, J. Jirmann, U. Krainick, "Implantierbarer Neurostimulator mit programmierbarer Logik" (Implantable Neurostimulator Equipped With a Programmable Logic Unit), Biomedizinische Technik [Biomedical Technology] 35, Supplemental Volume 2, pages 138-140). The programming device changes all operating parameters which are then transferred by way of a suitable interface into the memory of the patient device.
When turned on, the patient device wirelessly transmits to the implant all individually adapted operating parameters --with the patient being able to vary only the amplitude and the duration of the stimulation pulse within certain limits--and additionally also the energy required for operation. The implant includes a circuit which generates a controlled supply voltage from the received carrier and operates with undervoltage detection. The implant includes a circuit for receiving, demodulating and converting the electrode selection word transmitted immediately before the stimulation pulse into an 8-bit data word which, after checking, is forwarded to the CMOS electrode selector switch. After demodulation and amplification in an analog circuit, the received stimulation pulse is output by the selected CMOS electrode selector switch to the predetermined electrode while an additional current measuring resistor measures the stimulation current and sends it, amplified by way of a measuring amplifier, to a passive telemetry circuit.
Counterproductive to the effective stimulation by the stimulation pulses is that the arrangement of the antenna does not ensure sufficient coupling of the transmitter during movements, particularly during a change in the patient's position during sleep. Rather, it is necessary to have a report from the implant to the patient device (passive telemetry by way of periodic detuning of the energy transmission circuit) requesting the patient to maintain the necessary conditions.
In connection with the implementation of electrostimulation it is already known to support the latter by chemical agents. These active substances are usually also supplied to the patient's body by way of injections or as medication supplied in the form of pills and the like or also externally, but it is difficult to locally concentrate the effect of such medications. To this end, special patches are known which dispense dosages of long-term medications. The realizable effects, however, are not suitable to basically reduce the energy consumption of the neurostimulator.
SUMMARY OF THE INVENTION
It is the object of the invention to improve the effect
of an electronic circuit of the above-mentioned type with low energy consumption.
Based on the known general sequence of the operation and function of nerve cells, it is possible to exert a controlling influence on this sequence in that electrostimulation of the central or peripheral nervous system causes active chemical agents to be released within local limits.
The invention is based on the realization that, in contrast to the conduction of electrical charges (conduction of electrical excitations), nerve stimuli in the nervous system are also transmitted chemically by means of chemical transmitting agents (neurotransmitters). Neurotransmitters are synthesized at the ends of presynaptic fibers and are there stored in vesicles. If these neurotransmitters are released upon the arrival of an action potential, they quickly diffuse through the synaptic gap and produce a change in potential across the post-synaptic membrane, thus controlling the electrical conduction and excitation. The preganglionic neurons of the parasympathetic nerve and of the sympathetic nerve are, for example, cholinergic; the post-ganglionic neurons of the parasympathetic nerve are also cholinergic but the post-ganglionic neurons of the sympathetic nerve are noradrenergic. The inactivation is effected partly by chemical agents (for the case of acetylcholine by cholinesterase) partly by reintroduction into the vesicles (for the case of noradrenaline).
In this connection, it has been found to be advantageous that neurotransmitters act directly on the nerve function and excite them in such a way that, in spite of a reduction of the electrical energy, they react with preference to electrostimulation. During directed stimulation it appears that chemical agents are released that have a longer biological half-lifetime and block the path of the pain in the spinal cord. The energy consumption of the implanted neurostimulator is reduced by a time control unit which influences the height of the pulse amplitudes and/or the time intervals between the pulses and/or the pulse widths and the spacing between the bursts as well as the time and duration of the stimulation.
The time control unit of the electronic circuit of the neurostimulator is here adapted to the respective specific biological half-lifetime of these chemical agents so that their effect can be maintained quasi uniformly over a long period of time with a minimum of energy consumption.
BRIEF DESCRIPTION OF THE DRAWINGS
Advantageous features of the invention will be described in greater detail below together with a description of the preferred embodiment of the invention and the drawing figures, in which:
FIG. 1 is a block circuit diagram of an electronic circuit for an embodiment of the neurostimulator according to the invention;
FIG. 2 is an associated stimulation diagram; and
FIG. 3 is a block circuit diagram of a further embodiment of a circuit for a neurostimulator including a communication device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a block circuit diagram of an electronic circuit 10 of an embodiment of the neurostimulator according to the invention. It includes a time control unit 1, to which are connected a memory 2 for the value of the biological half-lifetime z, a memory 3 for the value of the pulse amplitude u, a memory 4 for the value of the duration d of an individual pulse, a memory 5 for the value of the pause between pulse packets p, a memory 7 for the frequency value f, a memory 8 for the value of the burst width b and a memory 9 for the values of the operating mode s. Corresponding to the value of the required dosage, values s are given in a memory 9 for the polarity of the pulse or for a change of polarity and for a soft start. By way of time control unit 1, the sequence and a neurostimulation generator 15 are controlled in such a manner that less energy is required if the neurons are excited locally by neurostimulation. By adapting the repetition rate of the stimulation to the half-lifetime of the body's own chemical agents, the neurotransmitters, the interval between the electrostimulation phases can be increased and thus energy can be saved.
For the purpose of programming, time control unit 1 may be charged with signals by way of a receiver 18 and permits a programmed influence on the time intervals between the electrostimulation phases corresponding to the biological half-lifetime of the released chemical agents of the body as well as all other parameters. The programming is effected at selectable intervals by means of an external programming unit 12.
FIG. 2 shows a typical stimulation diagram of a circuit according to FIG. 1. It is clearly visible that the time phases of the electrostimulation are a function of the biological half-lifetime while, the stimulation energy to be expended, and thus the dosage of the released chemical agents, is of a different magnitude at different locations. Not shown is how the individual zones can be stimulated in an alternating succession.
In the modification of the invention shown in FIG. 3 it is also possible, if suitable programming is provided, to change the local dosage of the chemical agents by way of an expanded external programming and monitoring unit 12 and by way of the given spacing between the electrostimulation phases as a function of the biological half-lifetime, and also to signal the dosage quantity value required, thus enabling the physician to monitor the required dosage quantity. For this purpose a stimulator control unit 17 is employed. It is connected by way of measuring lines with a current measuring resistor R in leads 19 that lead to electrodes 20. The thus measured momentary current value i is transferred to and stored in a memory 6. The stimulator control unit 17 continuously determines the current i by way of the current measuring resistor R and from it the dosage quantity value M or the tissue resistance Rg at the location where the electrodes are placed and, in connection with the latter, the momentary value z of the biological half-lifetime which, if required, can be read out from or predetermined by the external programming and monitoring unit 12. Thus, it is possible to detect changes in this respect and to evaluate them for renewed programming. The time control unit 1 and the associated memories 2 to 9 are grouped in planes A to C according to the locations of electrostimulation and treatment regions.
In an advantageous manner, time control unit 1 is configured, as far as its software is concerned, by a stimulator control 7 included in a microcomputer.
If multiple electrodes are implanted, the connection of the respective electrode 20 is effected by way of an electrode selector switch 16. The individual sections 13, 14 of the spinal cord may be stimulated individually one at a time or in succession. The effect then lasts longer in body regions A, B, C, etc.
The charge status of battery 11 is also constantly monitored by stimulator control unit 17 which also controls the spacing (pauses) between the pulse groups in which neurostimulator generator 15 emits bursts of pulses to at least one electrode 20 per stimulation location A, B and C, respectively. In these pauses p between pulse packets, the voltage of battery 11 is measured, which is then only under a minimum load (only stimulator control unit 17). In a known manner this permits a determination of the charge status which is stored intermediately in a further memory (not shown) and can be read out from there if required. The housing of the implantable neurostimulator 10 may be configured as a counter-electrode so that only one lead 19 per electrode 20 is required. The polarity of the pulses can be programmed and may change alternatingly, for which purpose memory 9 is connected to time control unit 1. The latter also controls a defined rise time for the pulses at the beginning and end of the pulse packet.
Although external programming and monitoring units 12 are known which are able to communicate with the implanted device and can be connected with a receiving and telemetry unit 18, the implant in the past has not operated autonomously but was always in communication with the patient device and required an external energy supply.
Additionally, it is now possible to automatically react to a changing stimulation threshold which is determined by time control unit 1 by way of a measurement of the tissue resistance Rg and the dosage quantity value M. The external programming and monitoring unit (12) can be connected with the receiving and telemetry unit (18) of the neurostimulator (10) at any desired time. In an advantageous manner, communication is effected by way of laser diodes and an at least partially light transmitting housing if the external programming and monitoring unit (12) is placed onto the skin under which the implant is disposed. During the other time, the implanted neurostimulator operates independently and, because of its battery 11, autonomously. Thus, the dependence on a transmitter-receiver coupling and the susceptibility to the patient's movements are eliminated.
The neurostimulation generator 15 to which electrodes 20 are connected at the one end of a line 19 acts within local limits at the other end of line 19 so that chemical agents are discharged that have a defined specific half-lifetime and produce a longer lasting effect in the Head's zones corresponding to the electrostimulation. Patient specific biorhythms can here be considered so that during a programmed time period, for example during an hour, stimulation bursts occur once for five minutes, thus optimizing the effect and making it last even longer.
If the coupling is made on a daily cycle, the pulse dosage during the night is reduced.
The invention is not limited in its embodiments to the above-described preferred embodiment. Rather, a number of variations are conceivable which take advantage of the described solution even for basically different configurations. | A neurostimulator for generating stimulation pulses for the central or peripheral nervous system, particularly against pain in the region of the spinal cord includes a control circuit for generating stimulation pulses with a pulse generator whose output is connected with stimulation electrodes. The stimulation pulses are generated at periodic intervals with an activity period corresponding essentially to an effective duration corresponding to a biological half-lifetime of a body's own active substances. The control circuit creates a respective rest period corresponding to a time required by the body's own active substances to regenerate themselves for a corresponding activity period. | 0 |
TECHNICAL FIELD
The present invention relates to building construction. In particular, it relates to a flooring system, including floor panel assemblies, wherein individual panels are interengaged to create a floor surface.
BACKGROUND OF THE INVENTION
Pre-fabricated floors and subfloors for permanent use in various kinds of buildings, including dwellings, industrial and office buildings, agricultural structures and others, are known. Generally, such systems comprise a supporting framework and an overlying floor material such as a plurality of panels or sheet material. Individual panels or floor material may be attached to the framework by various means.
Portable flooring such as portable stage flooring or false floors for providing space for conduits in buildings are known as well. This type of floor generally includes a framework for supporting moveable individual panels. The panels may have an edge adapted to be fitted with other abutting panel edges or with the supporting framework. Such floor systems may find particular applicability in temporary buildings such as on-site construction offices or other temporary structures. Additionally, such systems may be used as temporary floors in buildings under construction.
There are some problems which have not been completely addressed by existing flooring systems. One such problem is that it has been difficult to ensure that the upper surface of the plurality of panels comprising the floor or subfloor surface remains in horizontal alignment. Another problem is that it is difficult to maintain standardization of the various components comprising a floor system. For example, typical milled lumber has nominal dimensions only and there is always some variation. Builders frequently have to resort to shims or other devices to level the floor supports relative to one another or to level the floor panels with respect to one another and with respect to the supporting framework.
Another problem is that when a flooring surface is provided by a plurality of adjacent panels with abutting edges, the individual panels may deflect or be depressed relative to one another as weight is put on them. Again, traditionally, shims or fasteners have been used to control the deflection, but shims frequently require much time or effort to install, expending expensive manhours and increasing construction costs. A related problem is that with the passage of time, the shims may work free, generating expensive remedial work.
Clearly, there remains the need for a safe, durable and strong flooring system that substantially reduces cost of flooring, minimizes deflection in the floor system, yet is simple and cost effective to manufacture and install.
SUMMARY OF THE INVENTION
The present invention provides a flooring system that can be quickly, accurately and easily installed in various sorts of buildings, including temporary structures, pre-fabricated building or permanent structures such as factories, homes or offices. The flooring system broadly consists of individual panel assemblies that may be cooperatively interengaged. The periphery of each panel is bound by extruded frame members having two spaced generally parallel flanges and a generally perpendicular web extending therebetween. On one side of the web, between the upper and lower flanges, the frame members include track for receiving a key block. The key block comprises a generally rectangular base with a key tongue extending therefrom. The base is slidably received in the track of one frame member and the tongue is received in the track of an adjacent frame member. The fame members may be miter cut to a desired length and the corners fastened together by a corner fastener.
A feature of the present invention is that the frame members may be fastened together in any desired configuration for forming a plurality of interlocking complimentary floor panels. The panels are lightweight and convenient to store, transport and install.
Another feature of the present invention is interengaging of individual panels, whereby the surface of adjacent panels can be aligned and kept in alignment even when substantial weight or force is exerted downwardly on one panel.
It is an object of he present invention to provide a flooring system comprises of a plurality of adjacent complimentary, interengaged, framed panels that minimizes the deflection of adjacent panels, providing a more secure and aesthetically pleasing floor.
Another object of the present invention is to provide a durable flooring system that is inexpensive and cost effective to manufacture and requires no special tools to install. Additionally, the floor system may be installed temporarily in one location, yet easily may be taken apart, moved and reinstalled at another location.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view depicting a pre-fabricated dwelling of a type in which the present invention may be used.
FIG. 2 is a perspective view depicting the flooring system of the present invention and a typical support structure therefore.
FIG. 3 is a top plan view depicting the interengagement of individual floor panels into the flooring system of the present invention.
FIG. 4 is a perspective view depicting a single floor panel with portions broken away.
FIG. 5 is a perspective view depicting a joining element for the floor system of the present invention.
FIG. 6 is a fragmentary sectional view taken along line 6--6 in FIG. 4.
FIG. 7 is a side elevational view depicting a support stake with which the present invention might be used.
FIG. 8 is an enlarged fragmentary sectional view depicting a portion of one of the extruded frame members of the present invention.
FIG. 9 is a view similar to that of FIG. 8, depicting a fastener secured in a frame member.
FIG. 10 is a fragmentary sectional view taken along line 10--10 in FIG. 3.
FIG. 11 is a perspective view depicting a corner fastener for use with the present invention.
FIG. 12 is a fragmentary sectional view similar to that of FIG. 10 depicting a second embodiment of the corner fastener for use with the present invention.
FIG. 13 is a perspective view depicting the second embodiment of the corner fastener.
FIG. 14 is a fragmentary perspective view depicting the second embodiment of the corner fastener installed at a corner.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 3, the flooring system 20 of the present invention is depicted. The system 20 is made up of a plurality of individual floor panels 22 each having a frame 24.
A pre-fabricated building 26 of the type in which the flooring system 20 of the present invention might be used is depicted in FIG. 1. The building includes a roof 28, wall panels 30 and windows 32. An access door 34 and an entry stoop 36 are depicted as well. The floor system 20 of the present invention may be supported within the building 26 by the foundation 38 or by the second floor frame 40. It is within the scope of the present invention that the flooring system 20 of the present invention might be used in buildings having more than two stories; the building 26 depicted in FIG. 1 is representational only.
Although the details are not depicted, the foundation 38 of the building 26, as well as the second floor frame 40, may be typical sill and joist type foundations or frames upon which the floor system 20 of the present invention may rest.
Alternatively, the floor system 20 may be used with a supporting frame or foundation of the type depicted in FIG. 2. A plurality of stakes 42 support a support member 44. Individual floor panels 22 comprising the flooring system 20 rest on the support member 44. A stake is depicted in FIG. 7 and includes a shank 46 having a point 48 at one end and a support channel 50 at the opposite end. A wooden stake 42 is depicted, but other suitable materials, as well as lengths, may be used. Likewise, although a "block-type" support member 44 is depicted in FIG. 2, an I-beam support member 45 (depicted in FIG. 10) may be used with the present invention.
FIG. 4 depicts an individual floor panel assembly 22. The floor panel 22 has central flooring material 54 with a central area 53. The perimeter or edge of the flooring material 54 is bound and enclosed by extruded frame members 56. The frame members 56 broadly are modified I-beams including a generally central key track 58 on the outer side thereof. The key track 58 extends continuously for the length of a frame member 56 and receives a selected number of key blocks 60.
Each key block 60, depicted in FIGS. 5 and 6 comprises a general rectangular key block base 62 having an upper key bar 64 and a lower key bar 66. Extending from one side of the base 62, each key block 60 includes a rectangular tongue 68. The tongue has upper and lower chamfered edges 70.
FIGS. 8 and 9 depict how the finish floor material 54 or subfloor 55 may be secured to and cladded by the extruded frame members 56. Specifically, the extruded frame member 56 includes a fastening flange 78 having an upper surface 79 with a flashing channel 80 and an opposite bottom surface having a fastener point groove 82. FIG. 9 depicts the fastening flange 78 with a fastener 84 driven therethrough into a wooden subfloor member 55. A flashing burr 81 is depicted in the flashing channel 80, provided so that the burr 81 does not displace or raise the subfloor 55 away from the fame member 56 and fastening flange 78. The groove 82 is continuous along the length of the frame member 56, as is the flashing channel 80.
Additional detail regarding the extruded frame member 56 is depicted in FIG. 10. The frame member 56 includes a lower flange 90 and an upper flange 92. The fastening flange 78 is basically an extension of the upper flange 92. Opposite the fastening flange 78 and adjacent its outermost edge, the upper flange 92 has an upstanding lip 93. A central, generally upstanding web 94 extends between and is generally perpendicular to the upper and lower flanges 92, 90 respectively. Between the upper and lower flanges 92, 90 on the outside of the web 94 and the frame member 56, the frame member 56 has a key track 96. The key track 96 includes a lower channel 98 and an upper channel 100. The upper and lower channels 98, 100 are dimensioned to receive closely the upper and lower key bars 64,66 of the key block 60.
The frame member 56 include upper and lower corner fastening slots 102, 104, respectively. The slots 102, 104 extended into the member 56, are collinear with the web 94 and have serrated or ridged inner surfaces 106. The slots 102, 104 are generally centrally located with respect to the upper and lower flanges 90,92 and extend through the thickness of the flanges 90,92 into the web 94. It is within the scope of the present invention that upper and lower slots 102, 104 be provided as depicted or, alternatively, only an upper or only a lower slot may be used.
The upper flange 92 has a relatively larger outer surface area than the lower flange 90, extending inwardly toward the center 53 of the floor panel assembly 22 farther than the lower flange 90. Adjacent the innermost edge 107 of the upper flange 92, a screw fastener 84 is received in the point groove 82 and flashing channel 80 (as depicted in FIGS. 8 and 9). A staple-like corner fastener 108 is in the slots 102, 104.
FIG. 11 is a perspective view depicting the corner fastener 108. The fastener 108 has a generally L-shaped body with a base knife edge 110 and a flat upper surface 112. Vertical knife ribs 114 are provided on the sides 116 of the fasteners 108. Horizontal knife ribs (not depicted) also might be used.
FIGS. 12-14 depict a second embodiment of the present invention and, in particular, a second embodiment of an extruded frame member 210 and a fastener 211. Like the first embodiment frame member 56, the frame member 210 of the second embodiment includes upper and lower flanges 212,214 and a generally central web 216 extending perpendicularly therebetween. The upper surface of the upper flange 212 includes a fastener flange 217 having a fastener receiving slot 218. The outermost side of the frame member 210 relative to the general center of the flooring material 220 includes a key track 222, having a lower channel 224 and an upper channel 226.
The key block 60 depicted in FIG. 12 is substantially similar to the key block 60 depicted in FIG. 10 and is numbered commonly with the key block 60 of FIG. 10.
FIG. 13 shows the corner fastener 211 used to secure the frame members 210 together at the corners of a floor panel 22. Specifically, the second embodiment of the corner fastener 211 is a generally flat side fastener in an angle cut L-shape. The facing sides 238 of the L-shaped body of the second fastener 211 include tab receiving notches 240.
FIG. 14 depicts additional detail about how the second embodiment corner fastener 211 is received and fixed in a channel 218 in the frame member 210. A mitered corner 239 is depicted, a 45° cut having been made in two elongated sections of frame member material, creating frame members 210 and 210a. The upper and inside ledge 242 of the channel 218 includes a plurality of deflectable tabs 244. The tabs 244 may be located at regular intervals along the ledge 242 or may be provided at intermittent intervals along the ledge 242.
In use, the floor system 20 of the present invention may be installed on a block type member 44, a foundation 38 with a sill and joist arrangement, or an I-beam type support 45.
First, the individual floor panels 22 are manufactured and assembled. The size and perimeter configuration of the floor panels 22 may be selected and the required lengths of the extruded frame members 56 may be made by making miter cuts at 45° for rectangular or square panels. Appropriate joining cuts may be made for other geometric shapes for the panel 22.
A selected number of key blocks 60 may be slidably installed in the block receiving tracks 58 prior to connecting the frame members 56 at the corners of a panel 22. The key blocks 60 are freely slidable along the length of the track 58, whereby their positions relative to other adjacent floor panels 22 may be varied. Also, interference with electrical or other conduits in the building structure may be avoided by sliding the blocks 60 to an appropriate location. Generally, a block 60 may be placed approximately every two feet around the perimeter of a floor panel 22.
Next, either the first embodiment corner fastener 108 or the second embodiment corner fastener 211 is selected, depending upon which embodiment of the frame members 56 or 210 is selected. The first corner fastener 108, depicted in FIG. 10, is a friction-type fastener and is designed to be interference fit in slots 102, 104. The framing members 56 are aligned and the corner fastener 108 may be driven or hammered into tight frictional engagement at the intersection of the frame members 56, thereby holding the frame members 56 in the desired geometrical arrangement.
Subfloor panels 55 may be laid in place on the top of the frame members 56 within the confines of the lip 93. Screw fasteners 84 may be driven into the subfloor panel 55 through the upper flange 92 or 217 (in the second embodiment). Finally, a finish floor layer 54 may be installed over the subfloor panel 55.
It should be appreciated that a selected number of supplemental structural beams 57 (depicted in FIG. 6 and 10) may be used to span the distance between the frame members 56 either longitudinally or transversely. The structural beams 57 depicted in FIGS. 6 and 10 are typical I-shaped beams having angle-cut ends 59. The ends 59 enable the beams 57 to be supported adequately on the upper surface of the inside lip 91 of the lower flange 90, yet be rotated into place without interference from the frame members 56. Additional screw fasteners 84 may be used along the length of the beams 57 to secure the subfloor panel 55 to beams 57 after they have been rotated into place between the panel 55 and the lip 91.
FIG. 3 depicts a portion of the floor system 20 of the present invention as it might be installed in the building 26. Specifically, a number of individual floor panels 22 (as depicted in FIG. 4) have been laid tightly adjacent to one another. The tongue 68 of the key block 60 in one key track 58 of one floor panel 22 extends sufficiently far outwardly therefrom to enter the key track 58a of an adjacent floor panel assembly 22a. It should be appreciated that this engagement, carried across the extent of the floor system 20, aligns the adjacent panels and provides a substantial degree of structural integrity, preventing the deflection of adjacent panels 22,22a as weight is applied unequally to the upper surface thereof.
The floor system 20 of the present invention is lightweight, durable and can be assembled without requiring specially adapted tools. The material of choice for the extruded frame members 56 is aluminum; however, any suitable lightweight metallic or plastic material may be used a long as sufficient rigidity and tolerances are obtained. Likewise, the key blocks may be made from many suitable materials; nylon is one such material. The subfloor and finish floor material also may be selected from a variety of appropriate material. | The present invention provides a flooring system that can be quickly, accurately and easily installed in various sorts of buildings, including temporary structures, pre-fabricated buildings or permanent structures such as factories, homes or offices. The flooring system broadly consists of individual panel assemblies that may be cooperatively interengaged. The periphery of each panel is bound by frame members having two spaced generally parallel flanges and a generally perpendicular web extending therebetween. On one side of the web, between the upper and lower flanges, the frame members include a track for receiving a key block. The key block comprises a generally rectangular base with a key tongue extending therefrom. The base is slidably received in the track of one frame member and the tongue is received in the track of an adjacent frame member. The frame members may be miter cut to a desired length and the corners fastened together by a corner fastener. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a clutch device used in an automatic transmission for an automobile.
2. Description of the Related Art
In an automatic transmission used in an automobile, plural planetary gearsets are used. In this type of automatic transmission, plural clutch devices are used to perform gear shifting by changing the connections between the elements of the planetary gearsets.
To change from one gear ratio to the next gear ratio, for example, operations to rotate elements which were stationary before the shift, or to lock elements which were rotating before the shift, or to reverse the direction of the rotation of an element are required.
Therefore, a one-way clutch has been used to synchronize the engaging time of one clutch device with the disengaging time of another clutch device to carry out smooth shifting from the first gear to the second gear, a brake for locking the free-running function of the one-way clutch to attain engine braking in the first gear, another one-way clutch to synchronize the engaging time of one clutch device and the disengaging time of another clutch device to carry out smooth shifting from the second gear to the third gear, and another brake for locking the free running function of the latter one-way clutch to attain engine braking in the second gear (New Car Features of domestic TOYOTA CORONA FF Coupe, 4 Door Sedan, 5 Door, August 1985).
Thus, one-way clutches are required only for synchronizing the engaging time of one clutch device with the disengaging time of another clutch device, and it caused an increase of axial length, weight and cost.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide a clutch device which does not require one-way clutches for synchronizing engaging and disengaging times, or brakes to lock the free-running functions of these one-way clutches.
According to the present invention there is provided a clutch device, which comprises; a pair of members spaced on a common axis and relatively rotating around the common axis, a variable length coupling means, disposed on the common axis between the relatively rotating members, having a pair of cam members, and a piston means selectively pushing the variable length coupling means toward one of the relatively rotating members. The piston means cause frictional engagement between one end of the variable length coupling means and one of the relatively rotating members so that the cam members relatively rotate and cooperatingly generate a cam force in an axial direction which elongates the variable length coupling means and connects the relatively rotating member and the piston means pushes the variable length coupling means even when the direction of the relative rotation of the relatively rotating members is reversed.
The present invention will be more fully understood from the description of preferred embodiments of the invention set forth below, together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a schematic diagram of the automatic transmission having four forward speeds and one reverse speed;
FIG. 2 shows the combination of the clutch devices to be engaged at each range and gear ratio of the transmission of FIG. 1;
FIG. 3 is a sectional view of the transmission of FIG. 1 with a conventional structure;
FIG. 4 is a sectional view of the first embodiment applied in place of the third brake B 3 and the second one-way clutch F 2 of the conventional type transmission shown in FIG. 3;
FIG. 5 is a partial sectional view of the first embodiment, at disengaged condition with no oil pressure supplied to the piston;
FIG. 6 is a partial sectional view taken along the line A--A of FIG. 5;
FIG. 7 is a partial sectional view of the first embodiment, at a condition with piston pushing cam members fully to the right;
FIG. 8 is a partial sectional view taken along the line B--B of FIG. 7;
FIG. 9 is a partial sectional view of the first embodiment, in an engaged condition with cam members generating reaction force;
FIG. 10 is a partial sectional view taken along the line C--C of FIG. 9;
FIG. 11 is a partial sectional view of the first embodiment, in an engaged condition with a reversed torque input;
FIG. 12 is a partial sectional view taken along the line D--D of FIG. 11;
FIG. 13 is a partial sectional view of the second embodiment applied in place of the second brake B 2 and the first one-way clutch F 1 of the conventional type transmission shown in FIG. 3;
FIG. 14 is a partial sectional view of the second embodiment, at disengaged condition with supplying no oil pressure supplied to the piston;
FIG. 15 is a partial sectional view taken along the line E--E of FIG. 14;
FIG. 16 is a partial sectional view of the second embodiment, in a condition with the piston pushing the cam members fully to the left;
FIG. 17 is a partial sectional view taken along the line F--F of FIG. 16;
FIG. 18 is a partial sectional view of the second embodiment, in an engaged condition with the cam members being separated and generating reaction force;
FIG. 19 is a partial sectional view taken along the ling G--G of FIG. 18;
FIG. 20 is a partial sectional view of the second embodiment, in an engaged condition with a reversed torque input;
FIG. 21 is a partial sectional view taken along the line H--H of FIG. 20;
FIG. 22 is a partial sectional view of the third embodiment applied, in place of the third brake B 3 and the second one-way clutch F 2 , in the conventional type transmission shown in FIG. 3;
FIG. 23 is a partial sectional view of the third embodiment, in a disengaged condition with no oil pressure supplied to the piston;
FIG. 24 is a partial sectional view taken along the line I--I of FIG. 23;
FIG. 25 is a partial sectional view of the third embodiment, in a condition with the cam members being separated and generating no reaction force;
FIG. 26 is a partial sectional view taken along the line J--J of FIG. 25;
FIG. 27 is a partial sectional view of the third embodiment, in an engaged condition with cam members being separated and reacting;
FIG. 28 is a partial sectional view taken along the line K--K of FIG. 27;
FIG. 29 is a partial sectional view of the third embodiment, in an engaged condition with a reversed torque input;
FIG. 30 is a partial sectional view taken along the line L--L of FIG. 29;
FIG. 31 is a partial sectional view of the fourth embodiment applied to the first clutch B 3 and the second one-way clutch F 2 of the conventional type transmission shown in FIG. 3;
FIG. 32 is a partial sectional view of the fourth embodiment, in a disengaged condition with no oil pressure supplied to the piston;
FIG. 33 is a partial sectional view taken along the line M--M of FIG. 32;
FIG. 34 is a partial sectional view of the fourth embodiment, in a condition with the cam members being separated and generating no reaction force;
FIG. 35 is a partial sectional view taken along the line N--N of FIG. 16;
FIG. 36 is a partial sectional view of the fourth embodiment, in an engaged condition with cam members being separated and generating reaction force;
FIG. 37 is a partial sectional view taken along the line O--O of FIG. 18;
FIG. 38 is a partial sectional view of the fourth embodiment applied to the third brake B 3 in FIG. 1, in an engaged condition with a reversed torque input; and
FIG. 39 is a partial sectional view taken along the line P--P of FIG. 38.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, AT generally represents an automatic transmission, and comprises three sets of planetary gear units, plural frictional engagement devices to change operating conditions of the ring gears, and sun gears and carriers which compose the planetary gear units.
X i represents an input shaft and is connected with an output shaft of a torque converter (not shown).
PG 1 , PG 2 and PG 3 represent a front planetary gear unit, a rear planetary gear unit and an O/D planetary gear unit respectively.
R 1 , R 2 and R 3 each represent a front planetary ring gear, a rear planetary ring gear and an O/D planetary ring gear respectively.
K 1 , K 2 and K 3 each represent a front planetary carrier, a rear planetary carrier and an O/D planetary carrier respectively.
S 12 represents a front and rear planetary sun gear and S 3 represents an O/D planetary sun gear.
C 1 represents a first clutch which engages the input shaft X i with the front planetary ring gear R 1 .
C 2 represents a second clutch which engages the input shaft X i with the front and rear planetary sun gear S 12 .
C 3 represents a third clutch which engages the O/D planetary carrier K 3 and the O/D planetary sun gear S 3 .
B 1 represents a first brake which locks the clockwise and counterclockwise revolution of the front and rear planetary sun gear S 12 .
B 2 represents a second brake which locks the counterclockwise revolution of the front and rear planetary sun gear S 12 .
B 3 represents a third brake which locks the clockwise and counterclockwise revolution of the rear planetary carrier K 3 .
B 4 represents a fourth brake, which locks the clockwise and counterclockwise revolution of the rear planetary carrier K 3 .
F 1 represents a first one-way clutch which locks the counterclockwise revolution of the front and rear planetary sun gear S 12 .
F 2 represents a second one-way clutch which locks the counterclockwise revolution of the front and rear planetary sun gear S 12 .
F 3 represents a third one-way clutch which locks the counterclockwise revolution of the O/D planetary carrier in relation to O/D sun gear S 3 .
CG 1 and CG 2 respectively represents a counter drive gear and a counter driven gear for transmitting the engine torque, with a changed rotation speed, to a drive pinion which is an output shaft of the automatic transmission.
FIG. 2 shows the combination of the clutch devices to be engaged at each range and gear speed. As shown in FIG. 2, for example, to attain the first gear speed in the L range, the first clutch C 1 , the third clutch C 3 , the third brake B 3 , the second one-way clutch F 2 and the third one-way clutch F 3 should be engaged.
FIG. 3 is a sectional view of an automatic transmission with a conventional structure in which embodiments of the present invention, the details of which are described below, are applied.
FIG. 4 shows the first embodiment of the present invention which is applied to provide functions which are performed by the third brake B 3 and the second one-way clutch F 2 in case of the conventional type automatic transmission shown in FIG. 3.
By a construction and the operations described below, the second one-way clutch F 2 is not used.
In FIG. 4, reference numeral 1 represents a piston. A first cam member 2, a cam roller 3 and a second cam member 4 form a cam mechanism. A spring 5 always pushes the first cam member 2 and the second cam member 4, including the cam roller 3, to the left in the figure.
The clutch discs 6, which are connected to the rear planetary carrier K 2 , and the separator plates 7, which are connected to the outer casing of the automatic transmission AT, are selectively engaged with each other. A snap ring 8 limits the movement of the clutch discs 6 to the left, to prevent the clutch discs 6 from contacting with the second cam member 4 and interfere with the operation of the cam member 4. A clutch casing 9 has a recess in which piston 1 moves, and has an oil passage 10 to supply oil under pressure to the piston 1. An oil pressure control valve 11 controls the supply of oil under pressure to the piston 1.
Cam faces 2c 1 and 2c 2 and cam faces 4c 1 and 4c 2 are formed on the opposing surfaces of the first cam member 2 and the second cam member 4, as shown in FIG. 6.
Cam angle θ 1 of the cam faces 2c 1 and 4c 1 , and cam angle θ 2 of the cam faces 2c 2 and 4c 2 is, respectively defined so as to satisfy tan θ 1 <μ, and tan θ 2 >μ, where μ means the coefficient of friction between the second cam member 4 and the clutch disc 6.
Roller stoppers 2sf and 4sf, shown in FIG. 6, cooperatingly prevent the cam roller 3 from coming off the cam located part of the first cam member 2 and the second cam member 4 when the clutch disc 6 rotates counterclockwise.
Roller stoppers 2sr and 4sr, shown in FIG. 6, cooperatingly prevent the cam roller 3 from coming off the cam located part of the first cam member 2 and the second cam member 4 when the clutch disc 6 rotates clockwise.
FIGS. 5 and 6 show a condition with no oil pressure supplied and the first cam member 2 and the second cam member 4, including cam roller 3, are forced to the left end position by spring 5, so that the second cam member 4 and clutch disc 6 are separated. Thus the rear planetary carrier K 2 , which is connected to the clutch discs 6, is not locked regardless of the direction of the rotation.
FIGS. 7 and 8 show a condition when oil under pressure is supplied to the back surface of the piston 1 during the counterclockwise rotation of the clutch disc 6.
When oil under pressure is supplied to the back surface of the piston 1, the first cam member 2 and the second cam member 4, including the cam roller 3, are pushed to the right by the piston 1, so that, in due course, the back surface 4b of the second cam member 4 and a friction surface 6a of the clutch disc 6 engage with each other, as shown in FIGS. 7 and 8. Then, the second cam member 4 is dragged by the clutch disc 6 and begins to rotate in the same direction as the clutch disc 6.
In due course, as shown in FIGS. 9 and 10, the cam face 4c 1 of the second cam member 4 begins to climb the cam face 2c 1 of the second cam member 2 through the cam roller 3, so that a cam reaction force F CAM , which tends to push the first cam member 2 to the left and push the second cam member 4 to the right, is generated. Therefore, the piston 1 and the first cam member 3 is pushed to the left by a force F=F CAM -S×P, where S is a square measure of the action area of the piston 1.
Then, the back surface 2a of the first cam member 2 contacts the cam receiving surface 9a of the clutch housing 9, so that the first cam member 2 stops to move. Therefore, a cam reaction force F CAM generated by the further revolution of the second cam member 4 only acts to push the second cam member 4 to the right, so that the engagement force between the clutch disc 6 and the separator plate 7 becomes stronger. As a result, the clutch discs 6 and the separator plates 7 are completely engaged.
Thus the engagement of the clutch discs 6 and the separator plates 7 is performed by the cam reaction force F CAM which is proportional to the input torque.
If the oil pressure control valve 11 is switched to relieve the oil pressure after completion of the engagement, the force F becomes equal to a cam reaction F CAM and the clutch discs 6 and the separator plates 7 can be disengaged when the clutch disc 6 reverses the direction of the rotation from counterclockwise to clockwise, as described below.
When the clutch disc 6 rotates clockwise, the second cam member 4 also begins to rotate clockwise by being dragged by the clutch disc 6. In due course, the cam face 4c 1 descends the cam face 2c 1 through the cam roller 3 therefore the cam reaction force generated by the cam mechanism disappears, and then the first cam member 2 and the second cam member 4, including the cam roller 3, is pushed to the left by the biasing force of the spring 5. Therefore, the clutch discs 6 and the separator plates 7 are disengaged.
FIGS. 11 and 12 show the condition when the clutch disc 6 reverses the direction of the rotation from counterclockwise to clockwise while the oil pressure supply is maintained.
When the clutch disc 6 rotates clockwise, as described above, the second cam member 4 also begins to rotate clockwise by being dragged by the clutch disc 6. In due course, the cam face 4c 2 descends the cam face 2c 1 through the cam roller 3 and stops when the cam roller 3 reaches the roller stopper 2sr of the first cam member 2 and the roller stopper 4sr of the second cam member 4, as shown in FIG. 12.
By maintaining the oil pressure supply, the second cam member 4 is pushed to the right, so that the clutch discs 6 and the separator plates 7 can be kept in engaged condition. Therefore, the clockwise rotation of the rear planetary carrier K 2 can be locked.
If the oil pressure control valve 11 is switched to relieve the oil pressure and reverse the direction of the rotation to counterclockwise, then the clutch discs 6 and the separator plates 7 are disengaged.
The first embodiment of the present invention operates as described above, therefore the clutch discs 6, and accordingly the rear planetary carrier K 2 which is splined thereon, are changed to the required operating condition.
The operation locking the counterclockwise rotation of the rear planetary carrier K 2 , which is performed by locking function of the one-way clutch F 2 in the conventional type automatic transmission shown in FIG. 3, is performed under the conditions shown in FIGS. 9 and 10 in this first embodiment.
The operation leaving free the clockwise rotation of the rear planetary carrier K 2 , which is performed by a free running function of the one-way clutch F 2 in the conventional type automatic transmission shown in FIG. 3, is performed at the condition shown in FIGS. 5 and 6 this first embodiment.
The operation locking the clockwise rotation of the rear planetary carrier K 2 , which is performed by a braking function of the third brake B 3 in the conventional type automatic transmission shown in FIG. 3, is performed under the conditions shown in FIGS. 9 and 10 in this first embodiment.
The operation of instantaneously releasing the lock on the counterclockwise rotation of the rear planetary carrier K 2 required for the smooth shifting from the first gear speed to the second gear speed in D range, which is performed by the one-way function of the one-way clutch F 2 in the conventional type automatic transmission shown in FIG. 3, is performed by automatically releasing the cam functioning by giving a clockwise rotation to the rear planetary carrier K 2 .
Thus, according to the first embodiment of the present invention one device performs two kinds of functions which are performed by the third brake B 3 and the second one-way clutch F 2 in the conventional type automatic transmission shown in FIG. 3, and this allows the one-way clutch to be removed and accordingly decreases the axial length and the weight of the transmission.
FIG. 13 shows the second embodiment of the present invention which is applied to provide functions which performed by the first brake B 1 , the second brake B 2 and the first one-way clutch F 1 in case of the conventional type automatic transmission shown in FIG. 3.
By the construction and operations described below, the first brake B 1 and the first one-way clutch F 1 are removed, as a consequence.
In FIG. 13, a piston with a first cam member 12, cam roller 13 and a second cam member 14 form a cam mechanism. The piston with a first cam member 12 selectively pushes a second cam member 14, including a cam roller 13 located between the piston with first cam member 12 and the second cam member 14. Clutch discs which are splined to the front & rear sun gear S 12 are selectively and frictionally engaged with separator plates 16 which are connected to the outer casing of automatic transmission AT.
A snap ring 17 limits the movement of the clutch 1 discs 15 to the right, and prevents the clutch discs from contacting with the second cam member 14 and interfering with the operation of the second cam member 14. A spring 18 always pushes the piston with first cam member 12 to the right. A spring 20 always urges the second cam member 14 to the right. A clutch casing 19 has a recess in which the piston with first member 12 moves, and has an oil passage 21 to supply under pressure to the piston with first cam member 12. An oil pressure control valve 22 controls the supply oil under pressure to the piston with first cam member 12.
Cam faces 12c and 14c are formed on the opposing surfaces of the piston with first cam member 12 and the second cam member 14, as shown in FIG. 15.
The cam angle θ is defined so as to satisfy tan θ<μ, where μ means the coefficient of friction between the second cam member 14 and the clutch disc 15.
Roller stoppers 12sf and 14sf, shown in FIG. 15, cooperatingly prevent the cam roller 13 from coming off the cam disposed part of the piston with first cam member 12 and the second cam member 14 when the clutch disc 6 rotates counterclockwise.
Roller stoppers 12sr and 14sr, shown in FIG. 15, cooperatingly prevent the cam roller 13 from coming off the cam disposed part of the piston with first cam member 12 and the second cam member 14 when the clutch disc 16 rotates clockwise.
FIGS. 14 and 15 show a condition when no oil pressure is supplied and the piston with the first cam member 12 is pushed to the right end position by spring 18, so that the back surface 12b of the piston with the first cam member 12 contacts to a wall of the clutch casing 19, and the second cam member 14, including cam roller 13, is forced to the right end position by spring 20, so that the second cam member 14 and clutch disc 15 are separated. Therefore the front and rear sun gear S 12 which is connected to the clutch discs 6 is not locked regardless of the direction of the rotation.
When oil under pressure is supplied to the back surface of the piston with first cam member 12, the piston with first cam member 12 and the second cam member 14 are, with the cam roller 13, pushed to the left, so that in due course the back side 14b of the second cam member 14 and a frictional surface 15a of the clutch disc 15 begin to engage with each other as shown in FIGS. 16 and 17. Then, the second cam member 14 is dragged by the clutch disc 15 and begins to rotate in the same direction as the clutch disc 15.
In due course, as shown in FIGS. 18 and 19, the cam face 14c of the second cam member 14 begins to climb the cam face 12c of the piston with first cam member 12 through cam roller 13, so that a cam reaction force F CAM , which intends to push the piston with first cam member 12 to right, and push the second cam member 14 to the left is generated.
Therefore, the piston with first cam member 12 and the first cam member 3 is pushed to the right by the cam reaction force F CAM and stops when the cam roller 13 reaches the roller stopper 12sf of the piston with first cam member 12 and the roller stopper 14sf of the second piston 14.
In the above condition, a clearance is kept between the back surface of the piston with first cam member 12 and the piston receiving surface 19a of the clutch casing 19, so that the cam reaction force of the F CAM is received by a pushing force F PISTON which is generated by oil under pressure acting on the piston with first cam member 12. Herein, the force F PISTON =S×P, where S is the area of the action area of piston with first cam member 12 and P is the oil pressure. Therefore, the cam reaction force F CAM is limited by the force F PISTON and accordingly, the engaging force is controlled by the oil pressure.
As a result, the clutch disc 15 and the separator plate 16 are engaged and accordingly the clockwise rotation of the front and rear sun gear S 12 is locked.
If the oil pressure control valve 22 is switched to relieve the oil pressure at the above described condition, then the piston with first cam member 12 and the second cam member 14 are pushed to the left end positions by the spring 18 and 20 respectively, and the clutch discs 15 and separator plates 16 can be disengaged.
When the clutch discs 15 reverse the direction of rotation from counterclockwise to clockwise while keeping the oil pressure supply, the second cam member 14 also begins to rotate clockwise by being dragged by the clutch discs 15. In due course, the cam face 14c of the second cam member descends the cam face 12c of the piston with first cam member 12 through the cam roller 13 and stops when the cam roller 13 reaches the roller stoppers 12sr of the piston with first cam member and 14sr of the second cam member as shown in FIGS. 20 and 21, and the force F CAM generated by the cam mechanism disappears.
However, by maintaining the oil pressure supply, the clutch discs 15 are kept locked, because the back surface 14b of the second cam member 14 and the friction surface of the clutch disc 15 is kept engaged by the force of F PISTON . Therefore, the clockwise rotation of the front and rear sun gear S 12 is locked.
On the other hand, if the oil pressure supply is stopped or relieved so as to make the force of F PISTON zero after the rotation is reversed, then the piston with first cam member 12 is moved to the right end position by the spring 18 and the second cam member 14 is moved to the right end position by the spring 20 and the second cam member 14 and the clutch disc 15 are disengaged.
The second embodiment of the present invention operates as described above, therefore the clutch discs 15, and accordingly the front and rear sun gear S 12 which is splined thereon, are changed to the required operating condition.
The operation to lock the counterclockwise rotation of the front & rear sun gear S 12 , which is performed by a locking function of the one-way clutch F 1 cooperating with the second brake B 2 in the conventional type automatic transmission shown in FIG. 3, is performed under the operating condition shown in FIGS. 18 and 19 in this second embodiment of the present invention.
The operation freeing the clockwise rotation of the front and rear sun gear S 12 , which is performed by a free-running function of the one-way clutch F 1 in the conventional type automatic transmission shown in FIG. 3, is performed under the operating condition shown in FIGS. 14 and 15 in this second embodiment of the present invention.
The operation locking the clockwise rotation of the front and rear sun gear S 12 , which is performed by a braking function of the first brake B 1 in the conventional type automatic transmission shown in FIG. 3, is performed under the operating condition shown in FIGS. 20 and 21 in this second embodiment of the present invention.
The operation of instantaneously releasing the locking of the counterclockwise rotation of the rear planetary carrier K 2 required for the smooth shifting from the second gear speed to the third gear speed in the D range, which is performed by the one-way function of the one-way clutch F 1 in the conventional type automatic transmission shown in FIG. 3, is performed by automatically releasing the cam function by giving a clockwise rotation to the front and rear sun gear S 12 without supplying oil under pressure.
Thus, according to the second embodiment of the present invention one device performs plural functions which are performed by the first brake B 1 , the second brake B 2 and the first one-way clutch F 1 in the conventional type automatic transmission shown in FIG. 3, so that it is possible to remove the first brake B 1 and the first one-way clutch F 1 and accordingly decrease the axial length and the weight of the automatic transmission.
In addition to the above, smooth engaging is attainable because the engaging force is controlled by the force of F PISTON which is generated by the oil pressure.
FIG. 22 shows the third embodiment of the present invention which is applied in place of the third brake B 3 and the second one-way clutch F 2 of the conventional type automatic transmission shown in FIG. 3.
By the construction and operations described below, it is possible to remove the second one-way clutch F 2 .
In FIG. 22, a first cam member 23, a cam roller 24 and a piston with second cam member 25 form a cam mechanism. A pressure plate 26 is attached to the right end portion of the piston with second cam member 25. Clutch discs 27 and separator plates 28 are selectively engaged by the piston with second cam member 25 through the pressure plate. A snap ring 29 limits a movement of the clutch discs 27 and the separator plates 28 to the right. A spring 30 which is supported by a spring stopper 31 always pushes the first cam member 23 and the piston with second cam member 25, including the cam roller 24, to the left.
A clutch casing 32 has a recess in which the first cam member 23 and the piston with second cam member 25, with the cam roller 24, move, and an oil passage 33 to supply oil under pressure between the first cam member 23 and the piston with second cam member 25. An oil pressure controls valve 34 controls the supply of oil under pressure.
Cam faces 23c 1 and 23c 2 and cam faces 25c 1 and 25c 2 are respectively formed on the opposing surfaces of the first cam member and the piston with second cam member 25, as shown in FIG. 24.
Cam angle θ 1 of the cam face 23c 1 and 25c 1 is defined so as to satisfy tan θ 1 <μ, and cam angle θ 2 of the cam face 23c 2 and 25c 2 is defined so as to satisfy tan θ 2 >μ, where μ means the coefficient of friction between the engaging surfaces of the pressure plate 26 and the clutch disc 27.
Roller stoppers 23sf and 25sf, shown in FIG. 24, cooperatingly prevent the cam roller 24 from coming off the cam located portion of the first cam member 23 and the piston with second cam member 25 when the clutch disc 27 rotates counterclockwise.
Roller stoppers 23sr and 25sr, shown in FIG. 24, cooperatingly prevent the cam roller 24 from coming off the cam located portion of the first cam member 23 and the piston with second cam member 25 when the clutch disc 27 rotates clockwise.
FIGS. 23 and 24 show a condition with no oil under pressure supplied and the first cam member 23 and the piston with second cam member 25, with cam roller 24, are forced to the left end position by spring 30, so that the pressure plate 26 and the clutch disc 27 are disengaged. Therefore, the rear planetary carrier K 2 which is connected to the clutch discs 27 is not locked regardless the direction of the rotation.
FIGS. 25 and 26 show the condition when oil under pressure is supplied to the clearance between the first cam member 23 and the piston with second cam member 25 during the counterclockwise rotation of the clutch discs 27.
When oil under pressure is supplied to the clearance between the first cam member 23 and the piston with second cam member 25, the piston with second cam member 25 is pushed to the right, so that, in due course, the pressure plate 26 and the friction surface of the clutch disc 27 begin to engage with each other, as shown in FIGS. 25 and 26. Then, the piston with second cam member 25 is dragged by the clutch disc 27, and begins to rotate in the same direction as the clutch disc 27.
In due course, as shown in FIGS. 27 and 28, the cam face 25c 1 of the piston with second cam member 25 begins to climb the cam face 23c 1 of the first cam member 23 through the cam roller 24, so that a cam reaction force F CAM , which tends to increase the distance between the first cam member 23 and the piston with second cam member 25, is generated.
As the back surface of the first cam member 23 contacts the wall of the recess of the clutch casing 32, the cam reaction force generated by the further rotation of the piston with second cam member 25 only acts to push the piston with second cam member 25 to the right, so that the engagement force between the clutch discs 27 and the separator plates 28 becomes stronger. As a result, the clutch discs 27 and the separator plates 28 are completely engaged.
If the oil pressure valve 34 is switched off after completion of the engagement, the clutch discs 27 and the separator plates 28 can be disengaged when the clutch disc 27 reverses its direction of the rotation from counterclockwise to clockwise, as described below.
When the clutch disc 27 rotates clockwise, the piston with second cam member 25 also begins to rotate clockwise by being dragged by the clutch disc 27. In due course, the cam face 25c 1 descends the cam face 23c 1 through the cam roller 24 and then the piston with second cam member 25 is pushed to the left by the biasing force of the spring 30. Therefore, the cam reaction force generated by cam mechanism disappears and the clutch discs 27 and the separator plates 28 are disengaged.
FIGS. 29 and 30 show the condition when the clutch disc 27 reverses its direction of the rotation from counterclockwise to clockwise while the oil pressure supply is maintained.
When the clutch disc 27 rotates clockwise, same as described above, the piston with second cam member 25 also begins to rotate clockwise by being dragged by the clutch disc 27. In due course, the cam face 25c 1 descends the cam face 23c 1 through the cam roller 24 and stops when the cam roller 24 reaches the roller stopper 23sr of the first cam member 23 and the roller stopper 25sr of the piston with second cam roller 25, as shown in FIG. 30.
By maintaining the oil pressure supply, the piston with second cam member 25 is pushed to the right, so that the clutch discs 27 and the separator plates are kept in the engaged condition. Therefore, the clockwise rotation of the rear planetary carrier K 2 is locked.
The third embodiment of the present invention operates as described above, therefore the clutch discs 27, and accordingly the rear planetary carrier K 2 to which the clutch discs 27 is connected, are changed to the required operating condition.
The operation locking the counterclockwise rotation of the rear planetary carrier K 2 , which is performed by a locking function of the one-way clutch F 2 , in the conventional type automatic transmission shown in FIG. 3, is performed in the condition shown in FIGS. 27 and 28 in this third embodiment.
The operation for freeing the clockwise and counterclockwise rotation of the rear planetary carrier K 2 , which is performed by a free running function of the one-way clutch F 2 in the conventional type automatic transmission shown in FIG. 3, is performed in the condition shown in FIGS. 23 and 24 in this third embodiment.
The operation for locking the clockwise rotation of the rear planetary carrier K 2 , which is performed by a braking function of the third brake B 3 , in the conventional type automatic transmission shown in FIG. 3, is performed in the condition shown in FIGS. 29 and 30 in this third embodiment.
The operation for instantaneously releasing the lock on the counterclockwise rotation of the rear planetary carrier K 2 , required for the smooth shifting from the first gear speed to the second gear speed in the D range, which is performed by the one-way function of the one-way clutch F 2 in the conventional type automatic transmission shown in FIG. 3, is performed by automatically releasing the cam function by giving a clockwise rotation to the rear planetary carrier K 2 without supplying oil pressure.
Thus, according to the third embodiment of the present invention one device performs two kinds of functions which are performed by the third brake B 3 and the second one-way clutch F 2 in the conventional type automatic transmission shown in FIG. 3, and this allows the one-way clutch to be removed and the axial length and the weight of the transmission to be decreased.
FIG. 31 shows the fourth embodiment of the present invention which is applied in place of the third brake B 3 and the second one-way clutch F 2 of the conventional type automatic transmission shown in FIG. 3.
Using the construction and operations described below, the second one-way clutch F 2 can be omitted.
In FIG. 31, a first cam member 35, a cam roller 36 and a piston with second cam member 37 form a cam mechanism. A pressure plate 26 is attached to the right end portion of the piston with second cam member 37. Clutch discs 38 and separator plates 39 are selectively engaged. A snap ring 40 limits the movement of the clutch discs 38 and separator plates 39 to the left. A spring 41 always pushes the first cam member 35 and the piston with second cam member 37, including the cam roller 36, to the left.
A clutch casing 42 has a recess (no reference numeral) in which the first cam member 35 and the piston with second cam member 37, including the cam roller 3, move, and an oil passage 43 to supply oil under pressure to the back surface of the piston with second cam member 37. An oil pressure control valve 44 controls the supply of oil under pressure.
A cam faces 35c and 37c are respectively formed on the opposing surfaces of the first cam member 35 and the piston with second member 37, as shown in FIG. 33.
The cam angle θ of the cam face 35c and 37c are defined so as to satisfy tan θ<μ, where μ means the coefficient of friction between the piston with second cam member 37 and the clutch disc 38.
Roller stoppers 35sr and 37sr, shown in FIG. 33, cooperatingly prevent the cam roller 36 from coming off the cam located part of the first cam member 35 and the piston with second cam member 37 when the clutch disc 38 rotates clockwise.
FIGS. 32 and 33 show a condition with no supply of oil under pressure and the first cam member 35 and the piston with second cam member 37, including cam roller 36, are forced to the left end position by spring 41, so that the first cam member 35 and the piston with second cam member 37 are separated. Therefore, the rear planetary carrier K 2 , which is connected to the clutch discs 38 is not locked regardless the direction of its rotation.
FIGS. 34 and 35 show a condition, when oil pressure is supplied to the back surface of the piston with the second cam member 37 during the counterclockwise rotation of the clutch discs 38.
When oil under pressure is supplied to the back surface of the piston with the second cam member 37, the piston with the second cam member 37 is pushed to the right, so that, in due course, the piston with the second cam member 37 and the friction surface of the clutch disc 38 begin to engage with each other, as shown in FIGS. 34 and 35. Then, the piston with second cam member 37 is dragged by the clutch disc 38, and begins to rotate in the same direction as the clutch disc 38.
In due course, as shown in FIGS. 36 and 37, the cam face 37c of the piston with second cam member 37 begins to climb the cam face 35c of the first cam member 35 through the cam roller 36, so that a cam reaction force F CAM , which tends to increase the distance between the first cam member 35 and the piston with the second cam member 37, is generated.
As the back surface of the first cam member 35 contacts the wall of casing 42, the cam reaction force generated by the further rotation of the piston with second cam member 37 only acts to push the piston with second cam member 37 to the right, so that the engagement force between the clutch discs 38 and the separator plates 39 becomes stronger. As a result, the clutch discs 38 and the separator plates 39 are completely engaged.
If, the oil pressure valve 44 is switched off after the completion of the engagement, the clutch discs 38 and the separator plates 39 can be disengaged when the clutch disc 38 changes its direction of the rotation from counterclockwise to clockwise, as described below.
When the clutch disc 38 rotates clockwise, the piston with second cam member 37 also begins to rotate clockwise by being dragged by the clutch disc 38. In due course, the cam face 37c descends the cam face 35c through the cam roller 36 and then the piston with second cam member 37 is pushed to the left by the biasing force of the spring 41 and the cam reaction force generated by cam mechanism disappears, so that the clutch discs 38 and the separator plates are disengaged.
FIGS. 38 and 39 show the condition when the clutch disc 38 changes its direction of the rotation from counterclockwise to clockwise while the oil under pressure is supplied.
When the clutch disc 38 rotates clockwise, as described above, the piston with second cam member 37 also begins to rotate clockwise by being dragged by the clutch disc 38. In due course, the cam face 37c descends the cam face 35c through the cam roller 36 and stops when the cam roller 36 reaches the roller stopper 35sr of the first cam member 35 and the roller stopper 37sr of the piston with second cam member 37, as shown in FIG. 39.
By maintaining the supply of oil under pressure, the piston with second cam member 37 is pushed to the right, so that the clutch discs 38 and the separator plates are kept in engaged condition. Therefore, the clockwise rotation of the rear planetary carrier K 2 is locked.
The fourth embodiment of the present invention operates as described above and, therefore, the clutch discs 38, and accordingly the rear planetary carrier K 2 to which the clutch discs 38 are connected, are changed to the required operating condition.
The operation of locking the counterclockwise rotation of the rear planetary carrier K 2 , which is performed by a locking function of the one-way clutch F 2 in the conventional type automatic transmission shown in FIG. 3, is performed in the condition shown in FIGS. 36 and 37 in this fourth embodiment.
The operation for freeing the clockwise rotation of the rear planetary carrier K 2 , which is performed by a free running function of the one-way clutch F 2 in the conventional type automatic transmission shown in FIG. 3, is performed in the condition shown in FIGS. 32 and 33 in this fourth embodiment.
The operation of locking the clockwise rotation of the rear planetary carrier K 2 , which is performed by a braking function of the third brake B 3 in the conventional type automatic transmission shown in FIG. 3, is performed in the condition shown in FIGS. 38 and 39 in this fourth embodiment.
The operation for instantaneously releasing the lock on the counterclockwise rotation of the rear planetary carrier K 2 , required for the smooth shifting from the first gear speed to the second gear speed in the D range, which is performed by the one-way function of the one-way clutch F 2 in the conventional type automatic transmission shown in FIG. 3, is performed by automatically releasing the cam functioning by giving a clockwise rotation to the rear planetary carrier K 2 without supplying oil under pressure.
Thus, according to the fourth embodiment of the present invention one device performs two kinds of functions which are performed by the third brake B 3 and the second one-way clutch F 2 in the conventional type automatic transmission shown in FIG. 3, and this allows the one-way clutch to be removed and, accordingly, the axial length and the weight of the transmission to be decreased. | A clutch device which can perform the plural functions required in an automatic transmission is provided. As a result, it is possible to reduce the number of clutch devices required to obtain the desired gear ratios and shift operations. The clutch device, according to the present invention, comprises a pair of members spaced on a common axis and relatively rotating around the common axis, a variable length coupling member disposed on the common axis between the relatively rotating members and having a pair of cam members, and a piston member selectively pushing the variable length coupling member toward one of the relatively rotating members. The piston member causes frictional engagement between one end of the variable length coupling member and one of the relatively rotating members so that the cam members relatively rotate and cooperatingly generate a cam force, in an axial direction, which elongates the variable length coupling member and couples the relatively rotating members. The piston member pushes the variable length coupling member even when the direction of the relative rotation of the relatively rotating members is reversed. | 5 |
This is a Divisional of an application Ser. No. 11/685,934, filed on Mar. 14, 2007 now U.S. Pat. No. 7,787,979.
TECHNICAL FIELD
This disclosure generally relates to methods for assembling fuselage sections of aircraft, and deals more particularly with a method for assembling the fuselage sections using splice elements that compensate for gaps in mismatched surfaces between the fuselage sections.
BACKGROUND
The fuselage of large commercial aircraft is often manufactured by fitting and joining cylindrical fuselage sections sometimes referred to as “barrels”. The fuselage sections are assembled together using splice straps and splice elements that span the joint between the sections. Because of accumulated manufacturing variations in parts forming each section, sometimes referred to as tolerance stacking, small mismatches between mating surfaces of the fuselage sections create gaps that must be filled with shims or spacers. In the past, in order to determine the size and location of the gaps, the fuselage sections were fitted together and held in place using jigs or fixtures. Based on this preliminary “fit”, the gaps were measured and custom parts, spacers or shims were machined to fill the gaps.
Shims add parasitic weight to the aircraft, and are both time consuming and expensive to manufacture, since each shim is unique and must be machined to size by skilled craftsman. Furthermore, the process of physically fitting the fuselage sections together, determining the dimensions of the needed shims and then manufacturing the shims must be performed in a serial manner, all in a critical path of the manufacturing process. As a result, the shimming process adds to factory flow time.
Accordingly, there is a need for a method of assembling fuselage sections that eliminates the requirement for spacers and shims to fill gaps in mismatched, mating surfaces. Embodiments of the disclosure are directed toward satisfying this need.
SUMMARY
Illustrated embodiments of the disclosure provide a method for assembling fuselage sections of aircraft that eliminate the need for shims, spacers and other special parts to fill gaps between mating surfaces of the two sections. The elimination of shims and spacers reduces the weight of the aircraft as well as the time required for measuring surface mismatches, and fabricating/installing custom parts to compensate for these mismatches.
In accordance with one embodiment, a method is provided for assembling two fuselage sections of an aircraft. The method comprises the steps of: measuring the position of mating surfaces of the fuselage sections; virtually assembling the fuselage sections; generating the profile of splice elements used to join the fuselage sections based on the virtual assembly; producing a tool insert based on the splice element profile; producing splice elements using the tool insert; and, assembling the fuselage sections using the splice elements. The position of the mating surfaces of the two fuselage sections is preferably measured using non-contact measurement techniques, such as photogrammetry and/or laser tracking. Virtual assembly of the fuselage sections is performed using computer generated models of the two sections and comparing the computer models to identify gaps between mating surfaces of the sections. The tool insert may be produced using any of several solid free-form fabrication techniques, including three dimensional ink jet printing. The tool insert has a profile that is transferred to the splice element and compensates for mismatches between mating surfaces of the fuselage sections. The resulting splice element has a profile that fills the gaps caused by the mating surface mismatches. The splice elements may be formed by placing the tool insert into a tool base, introducing uncured material into the tool in contact with the insert, curing the material and removing the splice element from the tool. The uncured material is produced by forming a lay-up including multiple plies of fiber reinforced resin, and drawing the lay-up against the tool insert by applying a vacuum or other force.
According to another disclosed embodiment, a method is provided for manufacturing a splice element used to assemble fuselage sections of an aircraft. The method comprises the steps of: determining the position of mating surfaces of the fuselage sections in a common coordinate system; determining the profile of a splice element by generating a virtual fit between the fuselage sections; producing a tool based on the profile of the splice element; and, forming the splice element using the tool. The tool may be produced by providing a tool base, providing a tool insert and introducing the tool insert into the tool base. The tool insert possesses a profile complementing the profile of the splice element, and may be manufactured using computer automated, solid free-form fabrication techniques.
According to another embodiment, splice elements are provided for use in joining fuselage sections of an aircraft. The splice elements are manufactured by the steps comprising: generating computer models of the fuselage sections; mapping gaps between the mating surfaces of the fuselage sections using the computer models; generating profiles of splice elements respectively filling the mapped gaps; producing tool inserts having profiles respectively based on the profiles of the splice elements; and, forming the splice elements using the tool inserts.
Other features, benefits and advantages of the disclosed embodiments will become apparent from the following description of embodiments, when viewed in accordance with the attached drawings and appended claims.
BRIEF DESCRIPTION OF THE ILLUSTRATIONS
FIG. 1 is a perspective illustration of a fuselage section of an aircraft.
FIG. 2 is a perspective illustration of a portion of a joint formed between two fuselage sections using shims and spacers according to the prior art.
FIG. 3 is a sectional illustration taken along the line 3 - 3 in FIG. 2 .
FIG. 4 is an exploded, perspective illustration showing the relationship between a splice channel, and shims and spacers used in the prior art joint assembly shown in FIGS. 2 and 3 .
FIG. 5 is an illustration similar to FIG. 3 but depicting the use of a splice element made in accordance with embodiments of the disclosure.
FIG. 6 is a simplified flow diagram illustrating the steps of a method for splicing fuselage sections.
FIG. 7 is a perspective view of a joint formed between two fuselage sections before the installation of a splice element.
FIG. 8 is a sectional view taken along the line 8 - 8 in FIG. 7 .
FIG. 9 is a side illustration of a tool insert.
FIG. 10 is a fragmentary, side illustration of a lay-up used to produce a splice element.
FIG. 11 is a side illustration of a tool assembly containing a tool insert and a lay-up used to produce the splice element.
FIG. 12 is a side illustration of a finished splice element manufactured using the tool assembly shown in FIG. 11 .
DETAILED DESCRIPTION
FIG. 1 illustrates a typical fuselage section 10 of an aircraft. The fuselage section 10 includes an inner super-structure formed of various beams, supports and reinforcements. In the illustrated example, this super-structure is formed by circumferentially extending ribs 12 to which there are attached transversally extending beams 14 that are fastened to longitudinally extended beams 16 to form an upper floor normally supporting the passenger cabin. Struts 18 may be provided to aid in supporting the floor formed by beams 14 , 16 . A lower floor may also be provided to support a baggage compartment, comprising transversally extending beams 20 supported by struts 22 connected to the circumferential ribs 12 .
An outer skin 26 is secured to the circumferential ribs 12 and includes longitudinally extending stringers 24 . The outer edge of the skin 26 extends slightly beyond an outermost rib 12 and is intended to be fitted to the skin 26 formed around an adjacent fuselage section, as will become later apparent.
FIGS. 2 , 3 and 4 illustrate a prior art method of assembling two adjacent fuselage sections, for example a forward fuselage section 10 a and an aft fuselage section 10 b . The outer skins 26 a , 26 b of the respective fuselage sections 10 a , 10 b are joined along a circumferential joint indicated at 28 in FIG. 2 . A circumferentially extending splice strap 30 passes through tapered openings 39 in the stringers 24 . The splice strap 30 overlaps adjacent portions of the skin sections 26 a , 26 b and covers the joint 31 between these two adjoining skin sections. A plurality of splice channels 32 are respectively disposed between adjoining stringers 24 and cover portions of the splice strap 30 . Each of the splice channels 32 has a generally flat bottom and a pair of spaced apart reinforcement ribs 32 a . The splice strap 30 and the splice channels 32 are secured to the outer skin sections 26 a , 26 b using fasteners 40 , such as rivets.
As a result of normal variations in manufacturing processes and tolerance stacking, mating surfaces of the two fuselage sections 10 a , 10 b may not be perfectly aligned, resulting in possible gaps between the inner face of the skin sections 26 a , 26 b and the bottom face of the splice channel 32 . Moreover, the alignment mismatch between skin sections 26 a , 26 b may result in a gap between the splice channel 32 and the splice strap 30 . In order to fill the gaps mentioned above, fore and aft spacers 34 , 36 respectively, as well as a center shim 38 are provided to fill these gaps, as best seen in FIGS. 3 and 4 .
Referring now to FIG. 5 , in accordance with an embodiment of the invention, a splice element 42 is provided having a bottom profile tailored so as to fill any gaps that might otherwise be present between the splice element 42 and skin sections 26 a , 26 b , thereby obviating the need for shims or spacers. As will be discussed later in more detail, a method of manufacturing the splice element 42 is provided which results in thicknesses t 1 , t 2 , t 3 of the base 43 of the spliced element 42 that varies in accordance with the mismatch between outer skin sections 26 a , 26 b . In other words, the cross sectional profile of the base 43 of the splice element 42 is precisely tailored to match the underlying surfaces defined by skin sections 26 a , 26 b and the splice strap 30 .
Referring now concurrently to FIGS. 5-12 , the first step in the method of making the splice element 42 is shown at 44 in FIG. 6 in which the fuselage sections 10 and splice strap 30 are fabricated. Next, at step 46 , the fuselage sections 10 are individually measured, preferably using non-contact measurement techniques such as laser scanning and/or photogrammetry. For example, a merged photogrammetry/laser tracking technique can be used to measure the features on each of the fuselage sections 10 . Briefly, the merged photogrammetry/laser tracking technique involves measuring surfaces on the fuselage sections 10 utilizing photogrammetry and measuring these surfaces using laser tracking. Data is then generated that represents the position of one or more cameras used in the photogrammetry measurements. The generated position data is spatially linked to the photogrammetry measurements with the laser tracking measurements.
Using the measurement method described above, digital files are created that establish the relative positions of features on the fuselage sections 10 in a common coordinate system. Using these digital files, the fuselage sections 10 may be virtually assembled, without the need for actual physical assembly. Thus, for example the relative spatial positions of features on the fuselage sections 10 can be measured while the sections 10 are in two completely different geographic locations, and the digital files can be forwarded to a third geographic location where they are used to generate a computer model showing the relative positions of mating surfaces of the two fuselage sections 10 . At step 48 , the fuselage sections are virtually assembled so that the position of the mating surfaces defines the profile of the area for the splice elements 42 . In effect, this virtual assembly process maps the size and location of gaps that will be filled by tailoring the profile of the spliced elements 42 to precisely match the mating surfaces on the fuselage sections 10 .
The exact dimensions of the gaps requiring tailoring of the profile of the tool insert 54 may be determined using a technique for automatically determining shim dimensions. Briefly, this technique involves measuring the location of a first set of features on one fuselage section 10 and measuring the location of a second set of features on a second fuselage section 10 . Next, a virtual fit is generated between the two fuselage sections 10 based on the location measurements. Then, dimensions are generated of shims to be positioned between the two fuselage section 10 based on the generated virtual fit. Feature location measurement may be performed using both laser tracker and photogrammetry processes as described earlier. Generating the virtual fit may include performing a virtual nominal fit and then optimizing the virtual nominal fit. The virtual fit may be performed using computer models of the two fuselage sections and then comparing the computer models to determine the shape of voids requiring shims.
At step 50 , an exact replica of the virtually assembled surfaces is created which is then used to produce a tool insert 54 . The tool insert, as best seen in FIG. 9 , possesses a cross sectional profile which essentially matches the gaps that have been mapped between mating surfaces of the fuselage sections, in step 48 . Thus, the tool insert 54 has varying thicknesses t a , t b , t c which are the equivalent thicknesses of shims and spacers that would otherwise be needed in the absence of a splice element 42 having a customized profile. The tool insert 54 may be manufactured using a variety of techniques, including machining a solid piece of material. However, in one preferred embodiment, the tool insert 54 is manufactured using computer automated, solid free-form fabrication techniques.
Examples of such solid free-form fabrication include stereolithography, fused deposition modeling and 3-D ink jet printing. In 3-D ink jet printing, parts are built on a platform situated in a bin filled with powder material. An ink jet printing head selectively deposits or “prints” a binder fluid to fuse the powder together in the desired areas. Unbound powder remains to support the part. The platform is lowered, more powder is added and leveled, and the process is repeated, all under automated computer control. When finished, the green part is removed from the unbound powder and excess unbound powder is blown off. The finished part is infiltrated with wax, glue or other sealants to improve durability and surface finish.
The last step in the method is shown at 52 in FIG. 6 , in which the splice element is fabricated by placing a monolithic splice element lay-up over the tool insert so as to impart the profile of the tool insert into the lay-up. This manufacturing step is shown in more detail in FIGS. 10 and 11 . A lay-up 41 comprising multiple plies of a fiber reinforced synthetic resin, such as carbon fiber reinforced epoxy resin, is laid up so that the plies 43 are roughly tailored to match the final shape of the splice element 42 . Next, the tool insert 54 is placed in a tool base 56 . A vacuum bag 58 is placed over the tool base 56 and a vacuum is drawn within the bag 58 which forces the lay-up 41 down onto the tool insert 54 so that the profile of the tool insert 54 is imparted to the lay-up 51 . The lay-up 51 and tool assembly may also be placed in an autoclave (not shown) if desired, and then subjected to elevated temperature to cure the uncured or partially cured resin. Following curing, the completed splice element 42 shown in FIG. 12 is removed from the tool base 56 and then is placed over the splice strap 30 and skin sections 26 a , 26 b shown in FIGS. 7 and 8 . Finally, rivets or other fasteners 40 are used to secure the splice element 42 to the splice strap 30 and the fuselage skin sections 26 a , 26 b.
Although the embodiments of this disclosure have been described with respect to certain exemplary embodiments, it is to be understood that the specific embodiments are for purposes of illustration and not limitation, as other variations will occur to those of skill in the art. | Fuselage sections of an aircraft are joined using splice elements that compensate for gaps caused by mismatches between mating surfaces on the fuselage sections. The fuselage sections are virtually assembled using computer models that are based on non-contact measurements of as-built fuselage sections. The virtually assembled fuselage sections are used to map the gaps between the mating surfaces. The mapped gaps are used to produce tool inserts having profiles that reflect the dimensions of the gaps. The tool inserts are used to manufacture splice elements having profiles that fill the gaps when the fuselage sections are assembled and joined, thereby eliminating the need for shims and spaces to fill the gaps. | 1 |
BACKGROUND OF THE INVENTION
One or more embodiments of the present invention relate generally to methods for fabricating patterned features utilizing imprint lithography.
There is currently a strong trend, for example and without limitation, in the semiconductor manufacturing industry, toward micro-fabrication, i.e., fabricating small structures and downsizing existing structures. For example, micro-fabrication typically involves fabricating structures having features on the order of micro-meters or smaller.
One area in which micro-fabrication has had a sizeable impact is in microelectronics. In particular, downsizing microelectronic structures has generally enabled such microelectronic structures to be less expensive, have higher performance, exhibit reduced power consumption, and contain more components for a given dimension relative to conventional electronic devices. Although micro-fabrication has been utilized widely in the electronics industry, it has also been utilized in other applications such as biotechnology, optics, mechanical systems, sensing devices, and reactors.
As is well known, methods for fabricating patterned features are an important part of micro-fabrication. In the art of micro-fabrication of, for example and without limitation, semiconductor devices, “lift-off” is a well known method for fabricating patterned metal features such as, for example and without limitation, lines on a substrate or wafer. FIGS. 1A–1D illustrate a well known process for fabricating patterned metal features in which a photoresist mask is undercut by a developer prior to metal deposition. As shown in FIG. 1A , substrate 100 has been coated with photoresist layer 110 in accordance with any one of a number of methods that are well known to those of ordinary skill in the art, and photoresist mask layer 110 has been patterned in accordance with any one of a number of methods that are well known to those of ordinary skill in the art to provide aperture 120 having relatively straight side walls. For example, in accordance with one such lithography technique, photoresist 110 was exposed to a beam of electrons, photons, or ions by either passing a flood beam through a mask or scanning a focused beam. The beam changed the chemical structure of an exposed area of photoresist layer 110 so that, when immersed in a developer, either the exposed area or an unexposed area of photoresist layer 110 (depending on the type of photoresist used) was removed to recreate a pattern, or its obverse, of the mask or the scanning. Next, as shown in FIG. 1B , aperture 120 has been undercut in accordance with any one of a number of methods that are well known to those of ordinary skill in the art to form aperture 130 in photoresist mask layer 110 . Next, as shown in FIG. 1C , a relatively thin metal layer has been blanket-deposited over the structure shown in FIG. 1B . As is well known, metal thin film deposition techniques such as, for example and without limitation, physical vapor deposition (“PVD”) or sputtering (and excepting conformal deposition techniques such as, for example and without limitation, chemical vapor deposition (“CVD”) and electroplating) provide limited step coverage. As a result, metal deposited using such techniques does not coat steep or undercut steps. Thus, as shown in FIG. 1C , after blank metal deposition, the undercut side walls of aperture 130 are not coated. In other words, the use of undercut aperture 130 in photoresist mask layer 110 avoids side wall metal deposition, and provides discontinuous metal regions on substrate 100 and photoresist mask layer 110 . Lastly, as shown in FIG. 1D , a photoresist lift-off process has been carried out in accordance with any one of a number of methods that are well known to those of ordinary skill in the art to provide patterned metal feature 150 on substrate 100 . As is well known, during the lift-off process, photoresist material under metal film 140 is removed using, for example and without limitation, a solvent or a photoresist stripper. As a result, metal film 140 is removed, and patterned metal feature 150 that was deposited directly on substrate 100 remains.
Lithography is an important technique or process in micro-fabrication that is used to fabricate semiconductor integrated electrical circuits, integrated optical, magnetic, mechanical circuits and microdevices, and the like. As is well known, and as was discussed above, lithography may be used to create a pattern in a thin film carried on a substrate or wafer so that, in subsequent processing steps, the pattern can be replicated in the substrate or in another material that is deposited on the substrate. An imprint lithography technology for producing nanostructures with 10 nm feature sizes has been discussed in the literature. One embodiment of imprint lithography—referred to in the art as Step and Flash Imprint Lithography (“SFIL”)—is disclosed in an article by B. J. Smith, N. A. Stacey, J. P. Donnelly, D. M. Onsongo, T. C. Bailey, C. J. Mackay, D. J. Resnick, W. J. Dauksher, D. Mancini, K. J. Nordquist, S. V. Sreenivasan, S. K. Banerjee, J. G. Ekerdt, and C. G. Willson entitled “Employing Step and Flash Imprint Lithography for Gate Level Patterning of a MOSFET Device” SPIE Microlithography Conference, February 2003, which article is available on the Internet at www.molecularimprints.com, and which article is incorporated by reference herein. SFIL is a lithography technique that enables patterning of sub-100 nm features at a cost that has the potential to be substantially lower than either conventional projection lithography or proposed next generation lithography techniques. As described in the article, SFIL is a molding process that transfers the topography of a rigid transparent template using a low-viscosity, UV-curable organosilicon solution at room temperature with low pressure mechanical processes.
One such SFIL process is illustrated in conjunction with FIGS. 2A–2F . As shown in FIG. 2A , thinorganic layer 210 (referred to as a transfer layer) has been spin-coated on silicon substrate 200 . Next, a small amount of low viscosity, photopolymerizable, organosilicon solution 220 is dispensed over transfer layer 210 in an area to be imprinted (solution 220 is sometimes referred to as an “imprinting material”). The viscosity of solution 220 is sufficiently low so that minimal pressure (for example and without limitation, a pressure of about 2–4 psi) and no additional heating is necessary to move the liquid into an imprint template. For example, solution 220 may be a solution of an organic monomer, a silylated monomer, and a dimethyl siloxane oligomer (“DMS”) and a multifunctional cross-linker. Each component plays a role in the imaging process. For example: (a) the free radical generator initiates polymerization upon exposure to actinic (typically UV) radiation; (b) the organic monomer ensures adequate solubility of the free radical generator, desirable cohesive strength of cured imprinting material and adhesion to underlying organic transfer layer 210 ; (c) and the silylated monomers and the DMS provide silicon required to provide high-oxygen etch resistance (useful in subsequent processing steps described below); and (d) multi-functional crosslinker provides chemical crosslinking. In addition, these monomer types help maintain a low viscosity that is useful during imprinting. In further addition, the silylated monomer and the DMS derivative also lower the surface energy of solution 220 , thereby enhancing a separation process (described below). Advantageously, the organic monomer polymerizes in a fraction of a second using low cost, broadband light sources. For example, as described in the article, solution 220 consisted of 15% (w/w) ethylene glycol diacrylate (obtained from Aldrich Chemical Company of Milwaukee, Wis.), 44% (3-acryloxypropyl)tris(trimethylsiloxy)silane (obtained under the trade name SIA0210.0 from Gelest, Inc. of Morrisville, Pa.), 37% t-butyl acrylate (obtained from Lancaster Synthesis Inc. of Windham, N.H.), and 4% 2-hydrozy-2-methyl-1-phenyl-propan-1-one (obtained under the trade name Darocur 1173 from CIBA® of Tarrytown, N.Y.).
Next, as shown in FIG. 2B , template 230 —bearing patterned relief structures (for example and without limitation, a circuit pattern) and whose surface was treated with a fluorocarbon release film—was aligned over dispensed solution 220 and moved to decrease a gap between template 230 and substrate 200 . This displaced solution 220 , and filled the patterned relief structures on template 230 . Suitable release layers are described in an article by D. J. Resnick, D. P. Mancini, S. V. Sreenivasan, and C. G. Willson entitled “Release Layers for Contact and Imprint Lithography” Semiconductor International , June 2002, pp. 71–80, which article is incorporated by reference herein. As is known, it is desired that a template release layer has a low enough surface energy to enable template/substrate separation, and also is reasonably durably bonded to the template surface to remain functional after a number of imprints. Alkyltrichlorosilanes form strong covalent bonds with a surface of fused silica, or SiO 2 . In addition, in the presence of surface water, they react to form silanol intermediates which undergo a condensation reaction with surface hydroxyl groups and adjacent silanols to form a networked siloxane monolayer. When this functional group is synthetically attached to a long fluorinated aliphatic chain, a bifunctional molecule suitable as a template release film may be created. The silane-terminated end bonds itself to a template's surface, providing durability useful for repeated imprints. The fluorinated chain, with its tendency to orient itself away from the surface, forms a tightly packed comb-like structure, and provides a low-energy release surface. Annealing further enhances the condensation, thereby creating a highly networked, durable, low surface energy coating.
Next, as shown in FIG. 2C , once filling has occurred, the area is irradiated with broadband UV ultraviolet light (for example and without limitation, a 500 W Hg arc lamp) through a back side of template 230 , and cross-linking of solution 220 occurs.
Next, as shown in FIG. 2D , template 230 and substrate 200 are mechanically separated to expose cured, organosilicon relief pattern 240 (an imprinted version of the relief pattern in template 230 ) that is disposed on residual layer 250 (a residue of cross-linked solution 220 ). The SFIL steps illustrated in FIGS. 2A–2D may be carried out in a tool described by I. McMackin, P. Schumaker, D. Babbs, J. Choi, W. Collison, S. V. Sreenivasan, N. Schumaker, M. Watts, and R. Voisin in an article entitled “Design and Performance of a Step and Repeat Imprinting Machine” SPIE Microlithography Conference , February 2003, which article is available on the Internet at www.molecularimprints.com, and which article is incorporated by reference herein.
Next, etching is performed in a two-step process. S. C. Johnson, T. C. Bailey, M. D. Dickey, B. J. Smith, E. K. Kim, A. T. Jamieson, N. A. Stacey, J. G. Ekerdt, and C. G. Willson describe suitable etch processes in an article entitled “Advances in Step and Flash Imprint Lithography” SPIE Microlithography Conference , February 2003, which article is available on the Internet at www.molecularimprints.com, and which article is incorporated by reference herein. As set forth in the article, the first etch step, referred to as a “break-through etch,” anisotropically removes residual cross-linked layer 250 to break through to underlying transfer later 210 . The second etch step, referred to as a “transfer etch,” uses the remaining cross-linked relief pattern 240 as an etch mask to transfer the pattern into underlying transfer layer 210 . In one embodiment of SFIL, silicon in polymerized solution 220 , and lack of silicon in transfer layer 210 , provides etch selectivity between polymerized solution 220 and transfer layer 210 . In such an embodiment, the etching may be done in a LAM Research 9400SE obtained from Lam Research, Inc. of Fremont, Calif.
As shown in FIG. 2E , a halogen “breakthrough etch” was performed. For example and without limitation, the halogen etch described in the article was an anisotropic halogen reactive ion etch (“RIE”) rich in fluorine, i.e., wherein at least one of the precursors was a fluorine-containing material (for example and without limitation a combination of CHF 3 and O 2 , where the organosilicon nature of solution 220 called for the use of a halogen gas). Other suitable halogen compounds include, for example and without limitation, CF 4 . This etch is similar to a standard SiO 2 etch performed in modern integrated circuit processing. Lastly, as shown in FIG. 2F , an anisotropic oxygen reactive ion etch was used to transfer features 260 to underlying substrate 200 . The remaining silicon containing features 260 served as an etch mask to transfer the pattern to underlying substrate 200 . The “transfer etch” was achieved with a standard, anisotropic, oxygen RIE processing tool.
In order to imprint sub-100 nm features, it is useful to avoid intermixing between an imprinting material and a transfer layer. Intermixing may cause problems such as, for example and without limitation, distortion of features when an imprint template is separated from a substrate after exposure to polymerizing radiation. This can be particularly problematic when feature thicknesses are as small as 50 to 100 nm. In addition, intermixing may be particularly problematic when using an imprinting material comprised of low viscosity acrylate components because such components have solvency toward many polymers. Because of this, some have used a cross-linked BARC material (BARC or “bottom antireflective coating” is an organic antireflective coating that is typically produced by a spin-on process) as a transfer layer. However, because BARC is cross-linked, it cannot be undercut by conventional wet developers and removed by organic photostrippers. As a result, the above described method for fabricating patterned metal features using lift-off cannot be used.
In light of the above, there is a need for methods for fabricating patterned features utilizing imprint lithography that overcome one or more of the above-identified problems.
SUMMARY OF THE INVENTION
One or more embodiments of the present invention satisfy one or more of the above-identified needs in the art. In particular, one embodiment of the present invention is a method for generating patterned features on a substrate that includes: (a) forming a first layer on at least a portion of a surface of the substrate, the first layer comprising at least one layer of a first material, which one layer abuts the surface of the substrate; (b) forming a second layer of a second material on at least a portion of the first layer, which second layer is imprinted with the patterned features; (c) removing at least portions of the second layer to extend the patterned features to the first layer; and (d) removing at least portions of the first layer to extend the patterned features to the substrate; wherein the first layer and the second layer may be exposed to an etching process that undercuts the patterned features, and the first material may be lifted-off.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A–1D illustrate a well known process for fabricating patterned metal features in which a photoresist mask is undercut by a developer prior to metal deposition;
FIGS. 2A–2F illustrate a step-by-step sequence for carrying out one example of one type of imprint lithography process, a Step and Flash Imprint Lithography (“SFIL”) process;
FIGS. 3A–3I illustrate a step-by-step sequence for fabricating patterned features in accordance with one or more embodiments of the present invention utilizing imprint lithography;
FIG. 4 shows a portion of a structure of a chemical used to fabricate a planarization and transfer layer in accordance with one or more embodiments of the present invention; and
FIG. 5 illustrates an alternative step for that illustrated in FIG. 3B .
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 3A–3I illustrate a step-by-step sequence for fabricating patterned features in accordance with one or more embodiments of the present invention utilizing imprint lithography. Imprint lithography steps may be carried using a tool described by I. McMackin et al. in an article entitled “Design and Performance of a Step and Repeat Imprinting Machine” SPIE Microlithography Conference , February 2003, which article is cited in the Background of the Invention, and which article is incorporated by reference herein.
As shown in FIG. 3A , planarization and transfer layer 310 has been formed on substrate or wafer 300 using any one of a number of methods that are well known to those of ordinary skill in the art such as, for example and without limitation, by spin-coating to provide a substantially continuous, planar surface over substrate 300 . In accordance with one or more embodiments of the present invention, an inventive planarization and transfer layer is a polymer containing a poly(dimethylglutarimide) (“PMGI”) structure. FIG. 4 shows the structure of PMGI used to form the polymer of inventive planarization and transfer layer. Advantageously, in accordance with one or more embodiments of the present invention, a planarization and transfer layer based on PMGI has the following beneficial properties that solve one or more of the problems identified in the Background of the Invention: (a) little, if any, interfacial mixing with acrylic-based imprinting fluids; (b) such a planarization and transfer layer is removable in developer(s)/stripper(s), for example and without limitation, wet developer(s)/stripper(s) (it is believed that this is because such a planarization and transfer layer is not cross-linked by exposure to the UV radiation used to polymerize the imprinting fluid); and (c) such a planarization and transfer layer does not cross-link in response to UV radiation.
A polymer containing a PMGI structure that is suitable for use in carrying out one or more embodiments of the present invention may be obtained under the trade name SF7S (“PMGI SF7S”) from MicroChem Corp. of Newton, Mass. Other polymers containing a PMGI structure that are also suitable for use in carrying out one or more embodiments of the present invention may be obtained under the trade names LOL1000 and LOL2000 from Shipley Company, L.L.C. of Marlborough, Mass. In accordance with one embodiment of the present invention, PMGI SF7S was spin coated on a silicon wafer at about 3,000 rpm (conventional spin-coaters may rotate at speeds from about 500 to about 6000 rpm). The wafer was soft baked at about 180° C. for about 5 min, and a thickness of the PMGI layer was about 500 nm. Advantageously further embodiments of the present invention may be fabricated readily by one of ordinary skill in the art without undue experimentation since the developmental characteristics of a polymer containing a PMGI structure may be controlled by bake time and bake temperature.
As further indicated in FIG. 3A , feature pattern 325 has been fabricated on imprint template 330 using any one of a number of methods that are well known to those of ordinary skill in the art. In accordance with one or more embodiments of this imprint lithography process, imprint template 330 may have a nanoscale relief structure formed therein having an aspect ratio ranging, for example and without limitation, from about 1×10 −5 to about 10. Specifically, the relief structures in imprint template 330 may have a width that ranges, for example and without limitation, from about 10 nm to about 5000 μm, and the relief structures may be separated from each other by a distance that ranges, for example and without limitation, from about 10 nm to about 5000 μm. In accordance with one or more embodiments of the present invention, imprint template 330 may be comprised of material that is transparent, at least to a desired extent, to radiation utilized to cross-link an imprint fluid. Such material may be, for example and without limitation, SiO 2 , in the form of quartz, fused-silica, sapphire and the like.
In accordance with one or more embodiments of the present invention, a surface of imprint template 330 may be treated with a surface modifying agent such as a fluorocarbon silylating agent to promote release of imprint template 330 after transfer of feature pattern 325 . In addition, in accordance with one or more embodiments of this imprint lithography process, the step of treating the surface of imprint template 330 may be carried out utilizing a technique such as, for example and without limitation, a plasma technique, a chemical vapor deposition technique, a solution treatment technique, and combinations thereof. In accordance with one or more further embodiments of the present invention, the release properties of imprint template 330 may be improved by conditioning feature pattern 325 of imprint template 330 by exposing it to a conditioning mixture including an additive that will remain on imprint template 330 to reduce the surface energy of its surface. An exemplary additive is a surfactant such as, for example and without limitation, a mixture that includes approximately 0.1% or more of a surfactant available under the trade name ZONYL® FSO-100 from DUPONT™ having a general structure of R 1 R 2 where R 1 ═F(CF 2 CF 2 ) Y , with y being in a range of 1 to 7, inclusive and R 2 ═CH 2 CH 2 O(CH 2 CH 2 O) X H, where X is in a range of 0 to 15, inclusive—with the remainder comprising isopropyl alcohol (“IPA”) Exposure of feature pattern 325 may be achieved by virtually any manner known in the art, including dipping feature pattern 325 into a volume of the conditioning mixture, wiping the pattern with a cloth saturated with the conditioning mixture and spraying a stream of the conditioning mixture onto the surface. The IPA in the conditioning mixture is allowed to evaporate before using imprint template 330 . In this manner, the IPA facilitates removing, from the pattern, undesired contaminants while leaving the additive, thereby conditioning the surface of the pattern. In accordance with one or more still further embodiments of the present invention, the feature pattern of imprint template 330 may be conditioned by pattern priming. Pattern priming is achieved by selectively contacting the imprint fluid (to be described below) with the pattern a sufficient number of times to accurately reproduce a pattern complementary to the initial pattern. Specifically, by repeatedly contacting the imprint fluid, the complementary pattern formed improves with each successive imprint. After a sufficient number of imprints, an accurate complementary reproduction of the pattern in imprint template 330 is formed.
In addition, in accordance with one or more embodiments of the present invention, and has been indicated in FIG. 3A , release layer 320 has been deposited on imprint template 330 . An important factor in accurately forming feature pattern 325 is to reduce, if not prevent, adhesion of polymerized imprint fluid to imprint template 330 ′. A release layer is typically hydrophobic and/or has low surface energy. Providing polymerized imprint fluid with improved release characteristics minimizes distortions in feature pattern 325 recorded into the polymerized imprint fluid upon template separation. This type of release layer may be referred to as an a priori release layer, i.e., a release layer that is solidified to the mold. Suitable release layers are described in an article by D. J. Resnick, D. P. Mancini, S. V. Sreenivasan, and C. G. Willson entitled “Release Layers for Contact and Imprint Lithography” Semiconductor International , June 2002, pp. 71–80, which article is cited in the Background of the Invention, and which article is incorporated by reference herein.
As further indicated in FIG. 3A , imprint template 330 is aligned over and spaced apart from planarization and transfer layer 310 .
Next, as shown in FIG. 3B , polymerizable fluid 340 (also referred to as an “imprint fluid” or “imprint material”) has been dispensed over planarization and transfer layer 310 using any one of a number of methods that are well known to those of ordinary skill in the art such as, for example and without limitation, by dispensing as a plurality of fluid beads or droplets. As further shown in FIG. 3B , imprint template 330 has been brought close enough to polymerizable fluid 340 so that the features in feature pattern 325 of imprint template 330 have been filled with polymerizable fluid 340 . Note that polymerizable fluid 340 has a viscosity sufficiently low that it may rapidly and evenly spread and fill the features in an efficient manner, for example and without limitation, a viscosity in a range from about 0.01 cps to about 100 cps measured at 25° C. In addition, polymerizable fluid 340 has an ability to wet the surface of planarization and transfer layer 310 and imprint template 330 , and to avoid subsequent pit or hole formation after polymerization.
The constituent components that form polymerizable fluid 340 to provide the aforementioned characteristics may differ. This results from substrate 300 being formed from a number of different materials. As a result, the chemical composition of planarization and transfer layer 310 varies dependent upon the material from which substrate 300 is formed. For example, and without limitation, substrate 300 may be formed from silicon, plastics, gallium arsenide, mercury telluride, and composites thereof. Additionally, substrate 300 may include one or more layers, for example and without limitation, dielectric layers, metal layers, semiconductor layers, and the like.
In accordance with one or more such embodiments of the present invention, polymerizable fluid 340 comprises further constituents that provide its low viscosity, selectable etchability with respect to planarization and transfer layer 310 (to be described in detail below). In accordance with one or more such embodiments of the present invention, polymerizable fluid 340 is comprised of a silicon-containing material such as, for example and without limitation, an organosilane.
An exemplary composition for the silicon-containing material includes: (a) isobornyl acrylate (obtained from Aldrich Chemical Company of Milwaukee, Wis.); (b) acryloxymethyltrimethylsilane (obtained under the trade name XG-1039 from Gelest, Inc. of Morrisville, Pa.); (c) (3-acryloxypropyltristrimethylsiloxy)silane (obtained under the trade name SIA0210.0 from Gelest, Inc. of Morrisville, Pa.); (d) a fluorinated surfactant (obtained under the trade name FC4432 from 3M Company St. Paul, Minn.); (e) ethylene glycol diacrylate (obtained under the trade name EGDA from Aldrich Chemical Company of Milwaukee, Wis.); and (f) UV photoinitiator (for example and without limitation, 2-hydroxy-2-methyl-1-phenyl-propan-1-one) (obtained under the trade name Darocur 1173 from CIBA® of Tarrytown, N.Y.). In an exemplary such composition, isobornyl acrylate comprises approximately 30% by weight of the composition, acryloxymethyltrimethylsilane comprises approximately 40% by weight of the composition, (3-acryloxypropyltristrimethylsiloxy)silane comprises approximately 10% by weight of the composition, the fluorinated surfactant comprises approximately 0.5% by weight of the composition, ethylene glycol diacrylate comprises approximately 20% by weight of the composition, and the UV photoinitiator comprises approximately 3% by weight of the composition. Further useful compositions using the above-described materials may be determined readily by one of ordinary skill in the art without undue experimentation. Advantageously, little or no interfacial mixing occurs between polymerizable fluid 340 and planarization and transfer layer 310 for these above-described embodiments.
In accordance with one or more alternative embodiments of the present invention, polymerizable fluid 340 may comprise a nonsilicon-containing material such as, for example and without limitation, (a) isobornyl acrylate; (b) n-hexyl acrylate; (c) ethylene glycol diacrylate; and (d) 2-hydroxy-2-methyl-1-phenyl-propan-1-one. In one such exemplary composition, isobornyl acrylate comprises approximately 55% of the composition, n-hexyl acrylate comprises approximately 27% of the composition, ethylene glycol diacrylate comprises approximately 15% of the composition, and the UV initiator, for example and without limitation, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, comprises approximately 3% of the composition. The above-identified composition may also include stabilizers that are well known in the chemical art to increase the operational life of the composition. Further useful compositions using the above-described materials may be determined readily by one of ordinary skill in the art without undue experimentation.
To improve the release properties of imprint template 330 and polymerized layer 345 and to ensure that polymerized layer 345 does not adhere to imprint template 330 , the composition from which polymerizable fluid layer 340 is formed may include an additive that reduces the surface tension thereof. To that end, polymerizable fluid layer 340 may include, as an additive, a surfactant. For purposes of this patent application, a surfactant is defined as any molecule, one tail of which is hydrophobic. Surfactants may be either fluorine containing, e.g., including a fluorine chain, or may not include any fluorine in the surfactant molecule structure.
An exemplary surfactant is available under the trade name ZONYL® FSO-100 from DUPONT™ that has a general structure of R 1 R 2 where R 1 ═F(CF 2 CF 2 ) Y , with y being in a range of 1 to 7, inclusive and R 2 ═CH 2 CH 2 O(CH 2 CH 2 O) X H, where X is in a range of 0 to 15, inclusive. This provides one or more embodiments of polymerizable fluid 340 with the following composition: (a) isobornyl acrylate; (b) n-hexyl acrylate; (c) ethylene glycol diacrylate; (d) 2-hydroxy-2-methyl-1-phenyl-propan-1-one; and (e) R f CH 2 CH 2 O(CH 2 CH 2 O) X H. In accordance with one or more such embodiments, the ZONYL® FSO-100 additive comprises less than 1% of the composition, with the relative amounts of the remaining components being as discussed above. However, the percentage of ZONYL®FSO-100 may be greater than 1%. An advantage provided by the latter composition is that it may abrogate the need for an a priori release layer, i.e., a separate hydrophobic and/or low surface energy release layer disposed on imprint template 330 . Specifically, the latter composition provides desirable release properties to imprint template 330 and polymerizable fluid 340 so that polymerized layer 345 (described below) does not adhere to imprint template 330 with sufficient force to distort a feature pattern recorded therein.
FIG. 5 illustrates an alternative step for that illustrated in FIG. 3B . As shown in FIG. 5 , instead of using planarization and transfer layer 310 , substrate 300 has been covered using any one of a number of methods that are well known to those of ordinary skill in the art with two layers, i.e., planarization and transfer layer 310 1 and planarization and transfer layer 310 2 . In accordance with one or more embodiments of the present invention, planarization and transfer layer 310 1 is a polymer containing a PMGI structure, and planarization and transfer layer 310 2 is a DUV30J-6 BARC layer that is spin coated on top of planarization and transfer layer 310 1 . In accordance with one such embodiment, (a) the polymer containing a PMGI was formed as was described above; (b) the BARC layer was cured at about 180° C. for about 60 sec; and (c) polymerizable fluid 340 was a silicon containing fluid that was formed as was described above. Advantageously, little or no interfacial mixing occurs between polymerizable fluid 340 and planarization and transfer layers 310 1 and 310 2 for such alternative embodiments.
Next, as shown in FIG. 3C , the structure shown in FIG. 3B is exposed to blanket actinic radiation such as, for example and without limitation, UV radiation 335 , through imprint template 330 to cross-link a substantial portion of polymerizable fluid 340 and to convert it into polymerized layer 345 . For example and without limitation, polymerizable fluid 340 was exposed for about 30 sec to UV radiation (having a wavelength of about 365 nm and having an intensity of about 15 mW/cm 2 ). It should be understood that the particular radiation employed to initiate the polymerization of polymerizable fluid 340 may be determined by one of ordinary skill in the art depending on a specific application which is desired.
Next, as shown in FIGS. 3D and 3E , imprint template 330 is withdrawn to provide high resolution, low aspect ratio relief pattern 360 that defines a residual layer 365 in polymerized layer 345 . Also note residual material 365 that may be in the form of: (1) a portion of polymerizable fluid, (2) a portion of polymerized fluid, or (3) combinations of (1) and (2). Thereafter, relief pattern 360 is anisotropically etched to remove residual layer 365 using any one of a number of methods that are well known to those of ordinary skill in the art. A selective etch is then employed to etch both polymerized layer 345 and planarization and transfer layer 310 . In accordance with one or more embodiments of the present invention, the etching selectivity of planarization and transfer layer 310 relative to polymerized layer 345 may range, for example and without limitation, from about 1.5:1 to about 100:1. Further, in accordance with one or more further embodiments of the present invention, the selective etching may be carried out by a halogen-rich (for example and without limitation, fluorine rich) reactive ion etch process. Such halogen-rich etch processes may utilize precursors such as, for example and without limitation, CHF 3 and CF 4 . In addition, planarization and transfer layer 310 has been selectively etched to substrate 300 using any one of a number of methods that are well known to those of ordinary skill in the art to provide high resolution, high aspect ratio feature pattern 370 , with the features there comprising a stacked structure 371 that includes portions of polymerized layer 345 and planarization layer 310 . In accordance with one or more further embodiments of the present invention, the selective etching may be carried out by an oxygen plasma etch process. As is well known, such etching processes may be carried out in any one of a number of apparatus that are commercially available from suppliers such as, for example and without limitation, Lam Research, Inc. of Fremont, Calif.
Next, FIG. 3F shows aperture 380 that is a portion of high resolution, high aspect ratio feature pattern 370 illustrated in FIG. 3E .
Next, as shown in FIGS. 3H and 3G , the sidewalls of aperture 380 have been undercut by immersion in a developer/stripper, which developer/stripper etches the sidewalls (selectively with respect to cross-linked polymerized layer 345 ) to form stacked structure 371 with an aperture 390 having a re-entrant shape. For example, a polymer containing a PMGI structure can be developed/stripped in tetramethylammonium hydroxide (TMAH) that may be obtained under the trade name CD26 from Shipley Company, L.L.C. of Marlborough, Mass. In accordance with one such embodiment of the present invention, 0.26N TMAH (i.e., 0.26 normal concentration of TMAH, where 0.26N is an industry-accepted standard concentration for TMAH developer/stripper) was used. Advantageously, in accordance with one or more embodiments, polymerized fluid 345 does not etch (i.e., dissolve) in 0.26N TMAH while a polymer containing a PMGI structure etches (i.e., dissolves) slowly therein to provide undercutting. In accordance with one or more further embodiments of the present invention, polymerized fluid 345 may also be etched in a developer/stripper used to etch planarization and transfer layer 310 . However, it is believed that better undercutting is provided when the material forming polymerized fluid 345 etches only very slowly or at a slower rate than that of the material forming planarization and transfer layer 310 .
Next, as shown in FIG. 3H , a relatively thin metal layer 395 has been blanket-deposited over the structure shown in FIG. 5G utilizing a reasonably directional deposition technique such as, for example and without limitation, physical vapor deposition (“PVD”) or sputtering.
Next, as shown in FIG. 3I , a lift-off process has been carried out to provide patterned metal feature 400 on substrate 300 . For example and without limitation, a polymer containing a PMGI structure can be lifted off using an N-methylpyrrolidinone (“NMP”) based stripper such as, for example and without limitation, a stripper obtained under the trade name Remover 1165 from Shipley Company, L.L.C. of Marlborough, Mass. In addition, in accordance with one such embodiment, the substrate may be processed by ultrasonic immersion in Remover 1165 at, for example and without limitation, about 50° C.
Lastly, an optional final cleaning step may be performed by rinsing the wafer in IPA and blowing it dry. Optionally, this step may be followed by an oxygen plasma etching step.
Although various embodiments that incorporate the teachings of the present invention have been shown and described in detail herein, those skilled in the art can readily devise many other varied embodiments that still incorporate these teachings. For example and without limitation, further embodiments of the present invention exist wherein the planarization and transfer layer described above may be a high molecular weight (Mn>50,000) polyhydroxystyrene. However, for such embodiments, although such a planarization and transfer layer may slightly intermix with an acrylic-based polymerizable fluid, the combination may be suitable for certain applications. In addition, although the polymerizable fluid, as described above, is an acrylic-based composition, other embodiments exist wherein this is not the case. | One embodiment of the present invention is a method for generating patterned features on a substrate that includes: (a) forming a first layer on at least a portion of a surface of the substrate, the first layer comprising at least one layer of a first material, which one layer abuts the surface of the substrate; (b) forming a second layer of a second material on at least a portion of the first layer, which second layer is imprinted with the patterned features; (c) removing at least portions of the second layer to extend the patterned features to the first layer; and (d) removing at least portions of the first layer to extend the patterned features to the substrate; wherein the first layer and the second layer may be exposed to an etching process that undercuts the patterned features, and the first material may be lifted-off. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to a stone digger particularly of the form which can be supplied as an attachment to a conventional tractor.
In farming, stones and rocks can be a serious problem and much attention has been given in recent years to the development of rock pickers for collecting surface rocks and rocks which are close to the surface so that they do not interfere with later passage of seeding, cultivating and harvesting equipment. However, rock pickers are limited in relation to the size of rock that can be removed which leaves numbers of very large rocks, up to say three feet in diameter, which cannot be removed by the rock picker and yet provide a substantial obstacle to the later passage of other equipment.
Specialized stone digging equipment is available for removing such large stones. However, this tends to be expensive and thus has a limited market potential. The conventional back-hoe can also be used for removing stones of this type, but again the equipment is expensive and also of limited capabilities.
SUMMARY OF THE INVENTION
It is one object of the present invention, therefore, to provide a stone digging attachment which can be used with the conventional tractor, the attachment being of simple and inexpensive construction.
According to a first aspect of the invention, therefore, there is provided a stone digging attachment for the front end loader mechanism of a tractor of the type comprising, with the bucket removed, a pair of horizontally spaced lift arms and a pair of horizontally spaced hydraulic cylinders mounted above the lift arms, the attachment comprising a frame having a first pair of brackets for attachment to said lift arms and a second pair of brackets for attachment to said cylinders, and a pair of parallel spaced downwardly extending stone engaging tines mounted on said frame whereby the tines can be engaged into the ground against the stone by operation of said lift arms and cylinders for withdrawl of the stone from the ground.
According to a second aspect of the invention, therefore, there is provided a tractor having a front end loader mechanism of the type comprising, with the bucket removed, a pair of horizontally spaced lift arms and a pair of horizontally spaced hydraulic cylinders mounted above the lift arms, and a stone digging attachment mounted on said lift arms and said hydraulic cylinders and including means for engaging into the ground and contacting a stone for removing the stone.
It is a major advantage of the invention, therefore, that it can comprise merely a pair of cross members at right angles to the tines each carrying two pairs of flanges which enable the cross members to be coupled respectively to the lift arms and hydraulic cylinders of the front end loader mechanism of the tractor.
The tines can be formed from a pair of parallel spaced flat plates which are inclined downwardly and away from the brackets with a pointed end at the lower end inclined downwardly and forwardly relative to the brackets and the tractor so that the pointed end can be engaged onto the ground and pressed into the ground by operation of the hydraulic cylinders to wrap around the rock or stone which is partly under the ground.
The shape of the tines then allows the rock to be rolled out of the ground by reversing the tractor so that the full power of the tractor is available to roll the rock out of the ground. The edges of the plates at the point are preferably hardened to allow the tines to properly engage into the ground and around the rock without damage.
With the foregoing in view, and other advantages as will become apparent to those skilled in the art to which this invention relates as this specification proceeds, the invention is herein described by reference to the accompanying drawings forming a part hereof, which includes a description of the best mode known to the applicant and of the preferred typical embodiment of the principles of the present invention in which:
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of the stone digging attachment according to the invention, attached to the front end loader arrangement of a tractor, only part of which is shown.
FIG. 2 is a rear elevational view of the attachment of FIG. 1.
FIG. 3 is an isometric view from the front and one side of the attachment of FIGS. 1 and 2.
FIG. 4 is a side elevational view of the attachment mounted on a tractor shown in schematic working arrangement.
FIG. 5 is a view similar to that of FIG. 4 showing the movement by which a stone is removed from the ground.
In the drawings like characters of reference indicate corresponding parts in the different figures.
DETAILED DESCRIPTION
A tractor is shown schematically in FIG. 4 at 10 including a conventional front end loader generally indicated at 11 which is standard equipment on most farms. As conventional, the front end loader comprises a pair of lift arms 12 which are pivotally attached to the tractor and can be raised and lowered by a pair of hydraulic cylinders 13 operated from the tractor hydraulics.
In addition, tilt cylinders 14 are attached by a pivotal mounting bracket 15 to the lift arms 12. In conventional arrangement, a bucket is mounted on the pivot coupling at the front end of the lift arms 12 and the front end of the piston rods of the cylinders 14 so that they can be raised and lowered by the arms 12 and tilted by the cylinders 14. This is conventional equipment and does not need to be described in detail herein. It will, however, be appreciated that various designs of front end loader are available in different manufactures of tractors but the differences generally relate to differences in spacing and positioning of the arms and cylinders 12, 14.
Turning now to FIGS. 1, 2 and 3, the attachment comprises basically a pair of downwardly depending tines or blades 16, 17 which are formed from flat mild steel plate, preferably of one-inch thickness. The tines or blades 16, 17 are arranged in spaced and parallel relationship and are mounted upon a frame generally indicated at 18 which attaches the tines to the front end loader arrangement of the tracator.
The frame comprises a pair of I-beams 19 and 20 which are arranged in parallel spaced relation at right angles to the tines 16, 17. The I-beams are of a material which provides an 8-inch wide flange at 24 lbs. per foot of material and are interconnected by two pieces of the same material indicated at 21 which are welded to the top flange of the bottom I-beam 20 and the bottom flange of the top I-beam 19 with the flanges thereof at right angles thereto so as to interconnect the beams into a solid rectangular frame.
The tines or blades 16, 17 are attached to the frame by insertion into slots cut in the rear half of the flanges of the I-beams. Two of these slots are indicated in the top flange at 22, 23 respectively in FIG. 3. The corresponding slots in the bottom flange of the I-beam 19 and in the top and bottom flanges of the I-beam 20. These slots are generally visible in FIG. 2 and it will be noted that the blades 16, 17 are welded to the I-beams both at the slots and along the webs of the I-beams indicated at 24, 25 respectively.
The width of the blades 16, 17 is such that they extend beyond the end of the flanges of the I-beams to a position rearwardly of the frame 18. This section of the blade lies parallel to the frame, that is the rear wall 26 of the blade lies parallel to the webs 24, 25 of the frame.
Beyond the bottom of the frame, as defined by the bottom flange of the bottom I beam 20, the blades each include a rearwardly inclined portion 27, the front and rear walls of which are inclined to the wall 26 by an angle of the order of 10°. At a lowermost end of the portion 27, the front and rear walls are inclined forwardly as indicated at 28, 29 so as to form a forwardly projecting tooth 30 directly at the bottom of the blade 16, 17. The tooth 30 thus forms a projection which can be readily inserted into the ground.
In addition, the front wall indicated at 31 of the portion 27, together with the front wall 29 of the tooth portion provide a concave or cup shape for wrapping around the generally convex outer surface of a stone to be removed.
The edge surface of the blade at the tooth 30 and on either edge of the tooth running back for approximately three inches, is hardened by any conventional technique, generally by hard surfacing to increase the wearability of the mild steel from which the blades are cut.
With the opposite side of the I-beams 19 and 20 from the blades at 16 and 17, are provided a plurality of brackets generally indicated at 32. Each bracket is formed from a pair of parallel spaced flanges welded into the channel formed by the flanges and web of the respective I-beam. The flanges have aligned holes for receiving a cross pin or cross bolt by which a similar opening in the lift arms and tilt cylinders can be attached. The holes are indicated at 33 in FIG. 3 and bolts 34 shown in FIG. 1 pass through the holes to attach the lift arm 12 and cylinder 14 to the bottom and top I-beams respectively.
Although, as shown, the brackets 32 are of the same dimensions, that is they project slightly out of the channel formed by the I-beams 19, 20 thus providing the hole 33 at or adjacent the edge of the I-beam, they can be of different sizes to accommodate different relative positions of lift arm and tilt cylinder of different manufactured arrangements. Thus, the flanges providing the brackets 32 can be welded into place as the last item of the frame and tines with the spacing between the brackets and the position of the holes 33 relative to the I-beams being tailored to fit particular front loader arrangements.
Turning specifically to the side view of FIG. 1, it will be noted that the point 30 lies in line with the upper front edge of the respective tine with the recess defined by the rearwardly and forwardly inclined walls 31, 29 respectively being of the order of three inches. That is, the apex indicated at 35 is spaced three inches behind the line including the webs 24, 25 and the point 30.
In addition, the lowermost surface indicated at 36 which is inclined forwardly and downwardly to the point 30 is of the order of one and one-quarter inches higher at its rear end than at its front end at the point 30. The walls 28 and 29 are both of the order of six inches in length.
The width of the tines is of the order of nine inches and the spacing between them of the order of eighteen inches. The height of the frame is twenty-four inches and the width of the frame of the order of five feet. This allows the attachment to accommodate most types of front end loader arrangement merely by tailoring the mounting brackets 32 to the particular requirement.
Turning now to FIGS. 4 and 5, it will be noted that the mounting brackets 32 are arranged such that with the lift arms 12 in the lowered position, the lower portion 27 of the tine is inclined rearwardly and downwardly away from the tractor at an angle of the order of 45° so the point 30 projects effectively straight downwardly. In this position, the tilt cylinders 14 are operated to pivot the tines about the lower end of the lift arms so the point 30 is projected into the ground to engage a stone which can be as large as 3 to 4 feet in diameter at a position below its centre line. The point thus tends to engage the stone with the curvature of the stone sitting between the surfaces 31 and 29.
At this time the tractor is placed into reverse and moved away from the stone so that the stone is effectively rolled out of its hole onto the surface of the ground by the surfaces 29, 31 and also by the point 30 which particularly engages the stone and acts to roll it.
Since various modifications can be made in my invention as hereinabove described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without departing from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense. | A stone digging implement is manufactured as a simple and inexpensive attachment for the front end loader of a tractor. The attachment comprises a frame formed by a pair of horizontal I-beams which support a pair of hooked or pointed tines which extend downwardly from the I-beams for engaging the ground. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an improved flashing for roof-top vent pipes, comprising a thermoplastic hard base and an elastomeric rain collar. More specifically, the invention relates to an improved manner of connecting the hard base and rain collar together to form the completed flashing.
2. Brief Description of the Prior Art
Two-piece roof vent flashings are known. For example, British Patent 1,310,003 to BAMBROUGH shows a two-piece roof vent flashing, comprising an aluminum base element with a neoprene collar. The BAMBROUGH collar is connected to the aluminum base either through various mechanical connections, adhesives, or frictional attachments, depending on the particular embodiment. LOGSDON '347 (U.S. Pat. No. 4,160,347) describes a two-piece roof vent flashing comprising a base housing with a sealing collar. The sealing collar is mated with the base housing, and is mechanically held in position by a series of holding flanges on the interior wall of the base housing. LOGSDON '058 (U.S. Pat. No. 4,264,058) shows a two-piece roof flashing structure comprising a hard base and an elastomeric sealing collar. The sealing collar is molded directly onto annular supports, with a series of holes positioned in the inner annular support. During the molding process, material from the collar passes into holes in the inner annular support, thus creating a positive mechanical lock between the collar and base.
KIFER (U.S. Pat. No. 4,526,407) discloses an elastomeric sealing collar connected to a thermoplastic hard base. In KIFER, the sealing collar is molded to a flange on the hard base. The flange has a series of holes therethrough, so that a series of positive mechanical closed-loops are created between the hard base and sealing collar when the sealing collar is molded. HASTY (U.S. Pat. No. 4,864,782) discloses a thermoplastic hard base and an elastomeric sealing collar molded directly to a thermoplastic hard base. In HASTY, the flange has several holes therethrough, allowing the elastomeric material of the collar to pass through the holes during the collar's molding process. Thus, a series of positive mechanical connections are created between the hard base and sealing collar.
Prior art roof flashings involving thermoplastic to thermoplastic construction have relied on positive mechanical connections to maintain the two-part flashings together. One method in the prior art for creating a positive mechanical connection involves creating a flange on the base element, but with the flange having several holes of substantial size, as in HASTY and KIFER. These holes allow the elastomeric material of the collar to pass through the flange during the collar's molding process, thus creating a series of positive mechanical connections between the collar and the base element.
Several problems are created by the presence of holes in the flange. First, the holes necessarily compromise the structural integrity of the flange, increasing the likelihood of structural failure. The holes decrease the minimum path that water must follow to penetrate the flashing along the seam between the collar and the base element. Additionally, the perforated flanges increase the wastage resulting from molding the base element and from molding the collar onto the base element.
Solid flanges have been known in the art. For example, a roof flashing manufactured by the Never-Leak Company of Memphis, Tenn., has a solid flange. However, that flange is conical and relatively small in width.
Previous solid flange designs have been prone to failure of the seam between the flange and the collar, allowing water to penetrate. To compensate for anticipated seam failures, previous solid flanges have been generally conical in shape, with the conical flange sloping outwardly away from the center opening of the base element. Thus, water is diverted away from the center opening.
BRIEF SUMMARY OF THE INVENTION
The invention is an improved roof flashing for establishing a weather-proof seal with an upstanding pipe passing through an opening in a roof. The roof flashing comprises a base element and a collar, with the collar fitting tightly around the upstanding pipe to prevent water from passing through the roof flashing. The base element is integrally formed of thermoplastic and comprises a substantially planar base plate and an upstanding central dome-like portion with a central opening therein. The dome-like portion has a solid flange inwardly disposed and surrounding the central opening. The collar is integrally formed of elastomeric material and comprises a truncated, generally conical central portion and an outer, generally radially outwardly extending annular connecting portion. The central, conical portion of the collar has a hole sized to accommodate the upstanding roof pipe, such that the collar tightly fits around the upstanding pipe and prevents water from passing between the collar and pipe. The outer portion of the collar is molded directly to the solid flange portion of the base element, creating a strong, weathertight connection between the base element and collar.
The solid flange design adds greater strength and increased water-resistance to the roof flashing. When the collar is molded to the base element, the materials of the collar and base element are fused together along the seam between the collar and base element. This fusion between the two materials produces a strong, weathertight seal between the collar and base element. However, should the seam between the collar and base element be compromised such that water can pass along the seam, the solid flange creates a lengthy path the water must traverse before penetrating to the inside of the flashing.
In another embodiment, the solid flange includes raised ridges and/or recessed grooves. These ridges and grooves add additional surface area to the flange, thus increasing the area of fusion between the collar and base element and thereby strengthening the seam. Additionally, the ridges and grooves create additional obstacles to water penetration along the seam.
The above and other objects and advantages of the present invention will become more apparent when read in conjunction with the following description of a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a roof flashing according to one embodiment of the invention, showing the flashing in a typical roof installation.
FIG. 2 is a top plan view of a base element according to one embodiment of the invention.
FIG. 3 is a vertically cross-sectional view along the longitudal axis of a roof flashing according to the invention.
FIG. 4 is a fragmentary cross-sectional view of a portion of the roof flashing of FIG. 3.
FIG. 5 is a fragmentary cross-sectional view of a portion of a further embodiment of the invention.
FIG. 6 is a fragmentary cross-sectional view of a portion of a further embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows in perspective view a roof flashing 10 according to the invention in a typical roof-top installation. The roof flashing 10 provides a weathertight seal, preventing water from seeping through the roof 12 where the vent pipe 14 penetrates the roof. The assembly is not, of course, limited to use with vent pipes. It may be used with almost any pipe or other object passing through a roof, as well as in other weather-sealing applications.
The roof flashing 10 comprises a base element 16 and a sealing collar 18. As shown in the figure, the vent pipe 14 passes through a pipe opening 20 in the sealing collar 18. The sealing collar 18 preferably fits tightly about the vent pipe 14, creating a weatherproof seal about the pipe. The collar 18 is itself secured to a dome-like member 22 of base element 16, with the seam 24 between the sealing collar 18 and the base element 16 being weatherproof.
The roof flashing 10 is secured to the roof via a generally planar base plate 26 which comprises part of the base element 16. The planar shape of the base plate member 26 conforms to the planar surface of most roofs, allowing the assembly to lie flatly against a generally planar roof. For installations involving roofs (or other intended surfaces) which have non-planar surface, the base member 26 may be manufactured with a shape that will conform to the roof's surface.
In a pitched-roof assembly as in FIG. 1, the sealing collar is positioned at an angle to the planar base member 26.
FIG. 2 shows in top plan view a hard base element 16 according to one embodiment of the invention. The base element 16 comprises a generally planar base member 26 and a dome-like member 22 having a central opening 28. A ring mount flange 30 surrounds the central opening 28 in the dome-like member 22. The flange has an upper 32, lower 34, and inner 36 surface. The flange 30 is of a solid construction, with no holes passing through from top to bottom.
In the embodiment shown, the flange 30 has two ridges 38 about its circumference on its upper surface 32. Although the ridges 38 are shown in this example as being continuous, in other embodiments the ridges may each be comprised of one or more segments about the circumference of the flange 30. Two ridges are shown in the embodiment of FIG. 2, but any number of ridges may be used. In lieu of or in addition to the ridges, the flange 30 may have one or more grooves 44 on its upper and/or lower surfaces. Such grooves 44, which are discussed further below with respect to FIG. 5, do not pass through the flange 30.
The base element 16 is preferably formed of a thermoplastic during an injection molding process. However, other materials and molding processes may also be used.
FIG. 3 is a vertical section elevation view along the longitudinal axis of an assembled roof flashing 10 according to a preferred embodiment. The roof flashing 10 comprises the base element 16 from FIG. 2, but with the addition of an elastomeric sealing collar 18. The elastomeric collar 18 includes a generally circular pipe opening 20 through which a roof pipe can pass, with the collar 18 fitting tightly around the roof pipe to prevent the passage of water. The collar 18 further comprises a central portion 40 and an outer, generally radially outwardly extending annular connecting portion 42.
It should be noted that the collar 18 may be made with a variety of upper surface shapes and contours, including a substantially flat upper surface. However, for most installations, it is preferable that the collar's central portion 40 be somewhat conical. Such a conical shape helps to divert precipitation away from the collar's pipe opening 20.
During manufacture of the assembly, the base element 16 is molded in a first molding operation. Then, during a second molding step, the elastomeric collar 18 is molded directly onto the base element 16. During the second molding step, the materials of the collar 18 and the flange 30 are partially fused together along the common seam 24.
The material of the collar 18 may be different than the material of the base element 16. Increased strength of the common seam 24 can be achieved if, during the step of molding the collar to the flange, the material forming the collar is at a temperature approaching the melting point of the flange material. This encourages the materials of the flange and collar to fuse together, increasing the strength of the seam 24 between collar and base element.
As an example, in one embodiment the base element is formed of hard polypropylene, while the collar is formed of flexible polypropylene. When the flexible polypropylene of the collar is injected molded onto the base element, the hard polypropylene and flexible polypropylene fuse together along the common seam.
The annular connecting portion of the collar is molded directly to the flange 30. There is no positive mechanical connection between the collar 18 and the flange 30--instead, the connection between collar 18 and flange 30 is maintained by the bond created between the flange material and the collar material when the collar 18 is molded onto the flange 30.
FIGS. 4 and 5 shows flange designs having substantial irregularities on their upper and/or lower surfaces. In the embodiments of FIGS. 4 and 5, the substantial irregularities are ridges 38 and grooves 44, respectively. These substantial irregularities serve to increase the effective bonding area between the collar 18 and flange 30. Additionally, the substantial irregularities complicate and increase the width of the seam 24 between the collar and flange. A wider, more complicated seam is less easily breached by water.
FIG. 4 is a fragmentary cross-sectional view of the area immediate the flange 30 according to one embodiment of the invention. The embodiment shown comprises a flange 30 with two ridges 38 on its upper surface 32 and two ridges 38 on its lower surface 34. The ridges of opposite surfaces are shown offset with respect to one another, although the spacing of the ridges may vary as a matter of design. Additionally, any number of ridges may be used.
The cross-sectional shape of the ridges 38 is a matter of design choice. The ridges 38 depicted in FIG. 4 have generally rectangular cross-sections, which are relatively easy to mold.
In the embodiment shown, the collar 18 is molded across the upper 32, inner 36, and lower 34 surfaces of the flange 30. This maximizes the bonding area between the collar 18 and flange 30, as well as increasing the effective width of the seam 24. In a typical base element made in accordance with the invention, the flange 30 may be on the order of 1/4 to 1/2 inches or more in axial width. Since water would have to pass completely over the upper 32, inner 36, and lower 34 surfaces to penetrate the assembly, the distance involved to penetrate the seam, i.e., the minimum seam passage distance, would be on the order of 1/2 to 1 inches or more. Thus, in order for water to penetrate the seam, the seam would have to fail across its entire effective width (which is equivalent to the minimum seam passage distance), and then water would have to travel the minimum seam passage distance.
FIG. 5 shows in fragmentary cross-section another embodiment of the invention, where the flange 30 has, instead of ridges, a series of grooves 44 on its upper 32 and lower 34 surfaces. These grooves 44 serve substantially the same function as the ridges, including increasing the collar-to-flange bonding area and increasing the minimum seam passage distance along the seam 24 between the collar 18 and flange 30.
As shown in FIG. 5, the grooves 44 do not penetrate through the flange 30. As such, the flange 30 remains a solid structure, without perforations passing therethrough.
While the embodiment of FIG. 5 includes a series of two grooves 44 on both the upper 32 and lower 34 surfaces of the flange 30, the number of grooves on the upper 32 and lower 34 surfaces of different embodiments can vary from zero upwards. Additionally, the grooves may be combined with ridges, either on opposite or the same sides of the flange 30.
As with the ridges, the cross-sectional shape of the grooves 44 is a matter of design choice. Roughly rectangular cross-sections are depicted, which are relatively easy to mold. In preferred embodiments, the top opening of the groove is at least as wide as the widest inner width of the groove. This allows the base member to be easily constructed with known molding processes.
FIG. 6 shows in fragmentary cross-section still another embodiment of the invention, where the flange 30 has upper 32 and lower 34 surfaces which are substantially flat. A flat-surface flange simplifies the construction and operation of the molding apparatus. The flange has a planar (i.e., non-conical) shape. Although the resulting attachment seam 24 between the collar 18 and flange 30 defines a relatively smooth, unobstructed path, the bonding that occurs between the flange 30 and collar 18 in the collar's molding process makes the seam 24 weathertight and mechanically strong. Additionally, even if the seam 24 were somehow compromised so that water could pass therethrough, the distance which water must travel to penetrate the seam 24 is still relatively long.
Flat flange surfaces may be combined with ridged and/or grooved surfaces. For example, a flange may have a flat upper surface 32 and a ridged lower surface 34.
The above described preferred embodiments are intended to illustrate the principles of the invention, but not to limit its scope. Other embodiments and variations to these preferred embodiments will be apparent to those skilled in the art and may be made without departing from the spirit and scope of the invention as defined in the following claims. | An improved two-piece roof flashing comprises a thermoplastic hard base and an elastomeric rain collar. The hard base comprises a planar base plate with a central dome-like portion, with the dome-like portion having a central opening with a solid flange inwardly disposed and encircling the opening. The rain collar has a central opening sized to accommodate an upstanding roof pipe. The rain collar is molded directly onto the solid flange of the hard base, with the resulting seam between the rain collar and hard base being strong and weathertight. When the collar is molded onto the flange of the base element, the materials of the collar and flange fuse together along the seam between the collar and base element. Additionally, with the collar directly molded to the flange, the design of the flange creates a lengthy path that water must traverse in order to penetrate the roof flashing. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2009-150040, filed Jun. 24, 2009, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a wireless communication apparatus and its communication method.
2. Description of the Related Art
In recent years, electronic devices with a wireless communication function have been widely used. They include notebook-size personal computers (notebook PCs), game machines, car navigation systems, digital cameras, and personal digital assistants. Wireless LAN communication complying with the IEEE 802.11 standard and Bluetooth communication (registered trademark) are well known as wireless communication methods used in electronic devices with wireless communication functionality.
Wireless-LAN (IEEE 802.11b/g) and Bluetooth (IEEE 802.15.1) both use the 2.4-GHz frequency band. However, there is no interchangeability between the wireless methods (Wireless-LAN (IEEE 802.11b/g) and Bluetooth (IEEE 802.15.1)). Therefore, in an environment where wireless communication devices differing in communication method are close to one another, they communicate using the same frequency band in the same time period, which results in radio wave interference. This causes the problem of degrading the communication performance.
Specifically, the problem occurs when a plurality of devices which have the function of implementing different wireless communication methods are arranged closed to one another in the same device, such as a notebook PC or a personal digital assistant, or when they are installed in the same system LSI (Large-scale Integrated circuit).
As for a conventional method of alleviating the degradation of the communication performance, Jpn. Pat. Appln. KOKAI Publication No. 2004-363728 and Jpn. Pat. Appln. KOKAI Publication No. 2005-45330 have disclosed a method of, when IEEE 802.11b/g/n and Bluetooth (a registered trademark) mounted in the same device perform communication simultaneously, monitoring the communication state of each wireless function and, if one function is communicating, inhibiting the other from communicating.
BRIEF SUMMARY OF THE INVENTION
A wireless communication apparatus according to an aspect of the present invention includes;
a first wireless communication module which constitutes a first wireless communication system which transmits and receives first data to and from a first wireless device by a first communication method;
a second wireless communication module which constitutes a second wireless communication system which transmits and receives second data to and from a second wireless device in each interval time-divided with determined transmission timing by a second communication method differing from the first communication method;
an inhibit period generation module which generates inhibit periods for preventing the first wireless communication module from communicating by use of the first data, on the basis of information on the second communication method held in the second data and/or the transmission timing;
an occupation time calculation module which calculates an occupation time required for the transmission and reception of the first data; and
a transmission control module which compares the period between the inhibit periods adjacent to one another with the occupation time and, according to the comparison result, instructs the first wireless communication module to stop or delay the transmission of the first data.
A wireless communication method of apparatus according to an aspect of the present invention includes;
causing a first wireless communication module to transmit and receive first data to and from a first wireless device by a first communication method;
causing a second wireless communication module to transmit and receive second data to and from the wireless communication apparatus in each interval time-divided with determined transmission timing by a second communication method differing from the first communication method;
causing a generation module to generate inhibit periods for preventing the first wireless communication module from communicating by use of the first data, on the basis of information on the second communication method held in the second data and/or the transmission timing;
causing the first wireless communication module to check whether the communication module transmits and receives the first data to and from the first wireless device;
causing a calculation module to calculate an occupation time required for the first data to be transmitted and received if the first data is transmitted and received;
causing a control module to calculate the period between the inhibit periods adjacent to one another; and
causing the control module to compare the period with the occupation time and, according to the comparison result, instructs the first wireless communication module to stop or delay the transmission of the first data.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a concrete example of a wireless communication system according to a first embodiment of the invention;
FIGS. 2 and 3 are data formats used in the wireless communication system according to the first embodiment;
FIG. 4 is a block diagram of a wireless communication apparatus according to the first embodiment;
FIGS. 5A , 5 B and 5 C show an occupation period of data transmitted and received by the wireless communication system of the first embodiment;
FIGS. 6 and 7 are flowcharts to explain the wireless communication system of the first embodiment;
FIG. 8 is a time chart for a wireless communication system according to a second embodiment of the invention;
FIG. 9 is a time chart for a wireless communication system according to a third embodiment of the invention;
FIG. 10 is a time chart for a wireless communication system according to a modification of the third embodiment;
FIG. 11 is a time chart for a wireless communication system according to a fourth embodiment of the invention;
FIG. 12 is a block diagram of a wireless communication apparatus according to a fifth embodiment of the invention; and
FIG. 13 is a time chart for a wireless communication system according to the fifth embodiment.
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, referring to the accompanying drawings, embodiments of the invention will be explained. Like parts are shown by corresponding reference numerals throughout all the drawings.
[First Embodiment]
A wireless communication apparatus and its communication method according to a first embodiment of the invention will be explained with reference to FIG. 1 . FIG. 1 is a conceptual diagram of a wireless communication system according to the first embodiment. In the wireless communication system of the first embodiment, wireless communication complying with the IEEE 802.11 standard is performed.
Specifically, a unit equipped with a car navigation system (hereinafter, referred to as in-car unit 101 ) includes an IEEE 802.11 compatible wireless communication module which enables wireless communication complying with the IEEE 802.11(g/b/n) standard and a wireless communication module which enables wireless communication conforming to the Bluetooth (IEEE 802.15.1) standard.
An in-car display 102 includes an IEEE 802.11 compatible wireless communication module which enables wireless communication complying with the IEEE 801.11 standard.
A mobile telephone 103 includes a wireless communication module which enables wireless communication conforming to the Bluetooth standard.
The in-car unit 101 and in-car display 102 constitute a wireless LAN system conforming to the IEEE 802.11 standard. The in-car unit 101 and in-car display 102 can be connected to each other with a wireless LAN. The in-car unit 101 and mobile telephone 103 form a pico-net according to the Bluetooth standard. The in-car unit 101 and mobile telephone 103 can be connected to each other by Bluetooth.
In not only the first embodiment but also a second and a third embodiment of the invention explained later, the wireless communication module mounted on the in-car unit 101 and capable of Bluetooth communication functions as a slave and the mobile telephone functions as a master.
In the in-car unit 101 , the IEEE 802.11 compatible wireless communication module and the communication module capable of Bluetooth communication function may be provided in the form of separate wireless communication modules. Alternatively, the in-car unit 101 may be equipped with a wireless communication module which includes an LSI having both the IEEE 802.11 compatible wireless LAN function and the Bluetooth communication function.
As described above, the in-car unit 101 of the first embodiment employs different wireless communication methods. Accordingly, the in-car unit 101 performs wireless LAN communication with the in-car display 102 , while performing Bluetooth communication with the mobile telephone 103 .
The in-car display 102 may be equipped with an IEEE 802.11 compatible wireless communication module. Alternatively, the in-car display 102 may be configured to allow the insertion of a card with an IEEE 802.11 compatible wireless communication function and enable wireless LAN communication with a wireless communication base station (in this case, in-car unit 101 ).
Similarly, the mobile telephone 103 may be equipped with a communication module which enables a Bluetooth communication function. Alternatively, the mobile telephone 103 may be configured to allow the insertion of a card with a wireless communication function capable of Bluetooth communication and enable Bluetooth communication with a slave (in this case, in-car unit 101 ).
<Frequency Channel>
Next, frequency bands used in wireless LAN communication and Bluetooth communication will be explained.
<Wireless LAN Communication>
In wireless LAN communication in the wireless communication system of the first embodiment, wireless communication is performed at frequencies in a 2.4-GHz band. Specifically, the range of 2400 MHz to 2483.5 MHz is used. Thirteen frequency channels are allocated to the frequency band. The frequency channels are arranged at intervals of 5 MHz. In wireless communication conforming to the IEEE 802.11b/g standard, an approx. 20-MHz band is used. In wireless communication complying with the IEEE 802.11n standard, either an approx. 20-MHz band or a 40-MHz band is used. It is when there is no jamming caused by a wireless communication system using the same frequency band around the wireless communication apparatus that performs wireless LAN communication that the 40-MHz band is mainly used.
<Bluetooth Communication>
In Bluetooth communication in the wireless communication system of the first embodiment, wireless communication is performed at frequencies in a 2.4-GHz band. Specifically, as in wireless LAN communication, a frequency band ranging from 2400 MHz to 2483.5 MHz is used. In Bluetooth communication, channels are set at intervals of 1 MHz in the frequency band, providing a total of 79 frequency channels. That is, communication is performed at any one of 2402 MHz, 2403 MHz, 2404 MHz, . . . , 2480 MHz.
Furthermore, in Bluetooth communication, a frequency hopping method (described later) is used. Specifically, of the 79 frequency channels, the frequency to be used is switched 1600 time per second on the basis of a specific hopping pattern. That is, the frequency is switched at intervals of 625 μsec, thereby performing Bluetooth communication. By doing this, the frequency channel used is occupied. The 625-μsec interval is referred to as one slot. In other words, a slot is an interval during which a specific frequency is kept until the present frequency has changed to the next frequency in the hopping process of the frequency used in a pico-net. The slot is expressed in time. A unit serving as a reference for the timing with which packets exchanged between a master and a slave are transmitted and received is known as a slot.
<Frame>
The formats of frames transmitted and received in wireless LAN communication and Bluetooth communication will be explained.
<Frame Format Used in Wireless LAN System>
Next, the format of a MAC frame constituting data exchanged between the in-car unit 101 and in-car display 102 in the wireless LAN system will be explained with reference to FIG. 2 . FIG. 2 shows the format of a MAC frame created by a MAC layer module 212 . The MAC frame includes a header part, a Frame Body part, and a FCS part.
In the MAC header part, information needed for a reception process in a MAC layer is set. Specifically, the information includes a value indicating the type of frame (e.g., a data frame used in transmitting user data, a management frame used in a Beacon frame or the like, or a control frame, such as an Ack frame), a direct destination, address fields in which the final destination and the MAC address of the source are set, the sequence number of data to be transmitted, and a Sequence Control field in which a fragment number when data is fragmented is set.
In the Frame Body part, information according to the type of frame (e.g., data to be transmitted and received) is set.
In the FCS part, a Cyclic Redundancy Code (CRC) is set. CRC is used to determine whether the data held in each of the MAC header part and Frame Body part has been received properly.
<Frame Format Used in Bluetooth Communication>
Next, the configuration of the format of a packet exchanged between the in-car unit 101 and mobile telephone 103 in Bluetooth communication will be explained with reference to FIG. 3 . FIG. 3 shows an example of the format of a MAC frame created by a MAC layer module 222 .
The data format roughly includes an access code, a packet header, and a payload.
The access code has a data length of 68 or 72 bits. On the basis of the access code transmitted from the in-car unit 101 , the mobile telephone 103 recognizes the pico-net to which it belongs. Then, in the pico-net, the mobile telephone 103 can synchronize with the in-car unit 101 in communication. That is, the access code enables the in-car unit 101 and mobile telephone 103 in the pico-net to identify each other. When searching for the mobile telephone 103 (in an Inquiry process), the in-car unit 101 transmits data composed only of the access code. In data transmission using only the access code, the code has a data length of 68 bits. However, when a packet header is transmitted after the access code, the code has a data length of 72 bits.
The packet header has a data length of 54 bits. The packet header mainly performs communication control in the pico-net.
At the head of the packet header, AM_ADDR (not shown) is provided. AM_ADDR has a 3-bit value. AM_ADDR has addresses which enable up to 7 slaves to be recognized. That is, AM_ADDR has the following values: 001, 010, 011, . . . 111. Since the value of AM_ADDR is composed of 3 bits, the number of slaves that can be accommodated in the pico-net is up to 7.
Behind AM_ADDR, control data is provided. The control data part includes information indicating the aforementioned ACL link method or an SCO link method, explained later.
The payload has a data length of 0 to 2745 bits. The payload includes net data actually exchanged between the in-car unit 101 and mobile telephone 103 .
In the first embodiment, let transmitted and received Bluetooth packets be DM packets. A DM packet, which is a packet including a Forward Error Correction (FEC) code, is used in an Asynchronous Connection Oriented (ACL) link. Any one of a DM 1 , a DM 3 , and a DM 5 packet can be selected as a DM packet according to the amount of information transmitted at a time. Here, the expression DM 1 <DM 3 <DM 5 holds. Hereinafter, when a DM 1 packet is used, it will simply be referred to as a DM packet. The ACL link, which is a Point to Multipoint link including a master and a plurality of slaves, is used for data transfer between the master and a slave. Even if packets couldn't be transmitted from the master or a slave during communication due to degradation of the transmission line conditions, a specific quality is assured by transmitting the packets again. If the transmission line situation is good, a DH packet without the FEC code may be used. As for DH packets, too, any one of a DH1, a DH3, and a DH5 packet can be selected as a DH packet according to the amount of information transmitted at a time. Here, the expression DH1<DH3<DH5 holds. Especially, in the Bluetooth communication standard (Version 2.0+Enhanced Data Rate (EDR)), the maximum amount of information can be transmitted in wireless communication using 3-DH5 packets. The time required to transmit the maximum amount of information using 3-DH5 packets is 2878 μsec. This is called the maximum transmission time. The maximum transmission time is the transmission time required from when an antenna 240 starts to transmit one packet until it completes the transmission. The transmission time means the maximum time calculated from the determined modulation method, the number of bytes in a packet, the header length, and the like in Bluetooth communication.
<Configuration of in-Car Unit 101 >
Next, the configuration of the in-car unit 101 (wireless communication apparatus 200 ) will be explained with reference to FIG. 4 . FIG. 4 is a block diagram of the in-car unit 101 of the first embodiment. As shown in FIG. 4 , the wireless communication apparatus 200 included in the in-car unit 101 comprises a Bluetooth communication module (hereinafter, referred to as communication module 220 ), an IEEE 802.11 compatible wireless communication module 210 (hereinafter, referred to as communication module 210 ), an inhibit period generation module 230 (hereinafter, referred to as generation module 230 ), an occupation time calculation module 231 (hereinafter, referred to as calculation module 231 ), an antenna 240 , and antenna 250 . The communication module 210 includes a physical layer module 211 , a Medium Access Control (MAC) layer module 212 , and a transmission control module 213 . The communication module 220 includes a physical layer module 221 and a MAC layer module 222 .
<Antenna 240 and Antenna 250 >
The antenna 240 and antenna 250 will be explained. The antenna 240 and antenna 250 exchange signals in a high-frequency band used in performing communication on a wireless transmission path. The antenna 240 supplies the received wireless signal to the physical layer module 221 . The antenna 250 supplies the received signal to the physical layer module 211 . At the time of transmission, the antenna 240 outputs the wireless signal supplied from the physical layer module 221 . At the time of transmission, the antenna 250 outputs the wireless signal supplied from the physical layer module 211 .
<Communication Module 210 >
Next, the communication module 210 will be explained. The communication module 210 performs wireless communication conforming to the IEEE 802.11 standard. Specifically, the physical layer module 211 and MAC layer module 212 perform wireless communication complying with the IEEE 802.11 standard.
<Physical Layer Module 211 >
The physical layer module 211 includes a wireless module (RF (Radio Frequency) module) (not shown). Specifically, the physical layer module 211 down-converts a reception signal (analog signal) supplied from the antenna 250 and subjects the resulting reception signal to A/D (Analog to Digital) converter, thereby producing a digital signal. Then, the physical layer module 211 demodulates the digital signal. Specifically, the physical layer module 211 subjects the digital signal to, for example, Orthogonal Frequency Division Multiplexing (OFDM) demodulation and error-correction decoding, thereby obtaining a reception frame. Then, the physical layer module 211 outputs the obtained reception frame to the MAC layer module 212 . The physical layer module 211 may perform demodulation using a Direct Sequence method typified by the spectrum diffusion method instead of OFDM demodulation. In transmitting data, the physical layer module 211 subjects the transmission data supplied from the MAC layer module 212 to a specific modulation process, up-converts the resulting data, and supplies the up-converted data to the antenna 250 .
<MAC Layer Module 212 >
Next, the MAC layer module 212 will be explained. The MAC layer module 212 includes a transmission control module 213 .
The MAC layer module 212 performs specific access control complying with the IEEE 802.11 standard. Specifically, the MAC layer module 212 implements the CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) method. The CAMA/CA method determines whether to transmit a frame after monitoring the status of use of a wireless environment and further to check to see if there is any wireless communication apparatus which is performing wireless communication in the vicinity before transmitting the frame. If having determined that no wireless communication is being performed in its vicinity, the MAC layer module 212 , having received permission of transmission from the transmission control module 213 , transmits the frame to the physical layer module 211 . Moreover, the MAC layer module 212 not only adds a MAC header to data to be transmitted but also transmits an acknowledgement (Ack) frame in response to the received frame.
The transmission control module 213 controls the timing of transmitting a frame created by the MAC layer module 212 . The transmission control module 213 measures each of the Inter Frame Spacing (IFS) time and back off time. After the measured specific time has elapsed, the transmission control module 213 permits the MAC layer module 212 to transmit a frame. If having determined that wireless communication is in progress in its vicinity in the middle of measuring the total of the IFS time and the back off time or before the measurement, the transmission control module 213 interrupts the measurement again. Thereafter, if the MAC layer module 212 has determined that no wireless communication is being performed in its vicinity, the transmission control module 213 starts the measurement again.
The IFS time includes, for example, SIFS, PIFS, DIFS, and AIFS. An explanation will be given taking DIFS as an example.
DIFS is a value counted up during the period from when the signal power of frequency channels has dropped below a specific threshold value at which surrounding wireless communication systems cannot detect the signal power until it is determined that the surrounding wireless communication systems is in the idle state. That is, DIES is the minimum time to wait for before transmitting a frame after it has been determined that the surrounding wireless communication systems are in the idle state.
Furthermore, on the basis of an occupation time calculated by a calculation module 231 and an inhibit period signal generated by the generation module 230 , the transmission control module 213 determines whether frames in wireless LAN communication can be transmitted. Specifically, the transmission control module 213 compares the time required for the low (“L”) level transmission inhibit period output from the generation module 230 to change to the high (“H”) level one (hereinafter, referred to as the remaining period) with the occupation time from when the generation module transmits a frame until the module receives Ack in response to the frame. If the remaining period is longer, the transmission control module 213 permits the MAC layer module 212 to transmit a frame. If the remaining period is shorter than the frame, the transmission control module 213 inhibits the frame from being transmitted. A concrete communication method is to discard transmission frames, turn off the power supply of, for example, a wireless amplifier (not shown) included in the physical layer module 211 , or decrease the gain of the wireless amplifier to zero, thereby inhibiting frames from being transmitted. Here, to discard transmission frames means to discard the frames from a memory (not shown) included in, for example, the MAC layer module 212 . Before being supplied to the physical layer module 211 , the frames are stored in the memory. Even if the remaining period is shorter than the frame, the frame can be transmitted without interfering with data transmission by the communication module 220 by shortening the transmission frame length. To sum up, the transmission control module 213 performs the above control so as not to interfere with data communication by the communication module 220 .
The remaining period can be calculated when the transmission inhibit signal output from the generation module 230 and connection information on the communication module 220 are received. Connection information on the communication module 220 may be directly received from the communication module 220 or via the generation module 230 .
<Communication Module 220 >
Next, the communication module 220 will be explained. The communication module 220 performs Bluetooth communication conforming to the IEEE 802.15.1 standard. Specifically, the physical layer module 221 and MAC layer module 222 perform Bluetooth communication conforming to the IEEE 802.15.1 standard.
<Physical Layer Module 221 >
The physical layer module 221 includes a wireless module (RF module) (not shown). Specifically, the physical layer module 221 down-converts a reception signal (Bluetooth packet) supplied from the antenna 240 and then divides the resulting reception signal into, for example, streaming data packets and nonstreaming data packets. Thereafter, the physical layer module 221 demodulates the digital signals. Specifically, the physical layer module 221 performs time-division multiplex communication, a frequency hopping spectrum spreading method as a typical spectrum spreading method, and error correction decoding, thereby obtaining reception frames. That is, as time passes, the physical layer module 221 causes the frequency used to hop, thereby obtaining reception frames. Then, the physical layer module 221 outputs the obtained reception frames to the MAC layer module 222 . The physical layer module 221 may use OFDM. When data is transmitted, the physical layer module 221 subjects the transmission data supplied from the MAC layer module 222 to a specific modulation process, up-converts the modulated data, and supplies the resulting data to the antenna 240 .
<MAC Layer Module 222 >
The MAC layer module 222 performs specific access control complying with the Bluetooth communication standard. Specifically, the MAC layer module 22 performs connection processes (including, for example, an Inquiry process, an Inquiry Scan process, a Page process, and a Page Scan process) between the mobile telephone (master) 103 and in-car unit (slave) 101 , establishes a pico-net (including the synchronization of the master and slaves), and controls the data transmission and reception after the establishment of the pico-net. In the first embodiment, the communication module 220 functioning as a communication module for Bluetooth communication acts as a slave. The MAC layer module 222 synchronizes the mobile telephone 103 with a time slot on the basis of the internal clock of the mobile telephone 103 . That is, the MAC layer module 222 recognizes each of the timing (an odd-numbered slot) with which the module 222 transmits data and the timing (an even-numbered slot) with which the mobile telephone 103 transmits data. Then, the MAC layer module 222 outputs the recognized time slot number SN and connection information on the mobile telephone 103 to the generation module 230 . Here, connection information is transmitted and received information is exchanged between the communication module 220 and mobile telephone 103 . Specifically, connection information is information indicating that Bluetooth packets are being transmitted or received.
<Generation Module 230 >
Next, the generation module 230 will be explained. The generation module 230 controls a transmission inhibit signal output to the communication module 210 on the basis of the time slot number SN supplied from the MAC layer module 222 and connection information on the communication module 220 and mobile telephone 103 . In the first embodiment, the generation module 230 performs control as described in the following two items:
(1) The module 230 raises the transmission inhibit signal to a high (“H”) level for a specific period with the timing of transmission from the mobile telephone 103 or in an even-numbered slot.
(2) The module 230 raises the transmission inhibit signal to a high level during a specific period from when the mobile telephone 103 receives data in an even-numbered slot until the in-car unit 101 responds to the data in an odd-numbered slot following the even-numbered slot.
The “H” level means the inhibition of transmission of data by the communication module 210 . In the Bluetooth communication standard, an error of 10 μsec in the timing with which the master and a slave exchange data is allowed. That is, for example, the timing with which the mobile telephone 103 transmits data in an even-numbered slot is allowed to overlap with an odd-numbered slot by 10 μsec. The same holds true for the timing with which the in-car unit 101 transmits data. Accordingly, in the first embodiment, the transmission inhibit signal is made high (“H”) during the period from 25 μsec before an odd-numbered slot changes to an even-numbered slot until 25 μsec after the odd-numbered slot has changed to the even-numbered slot. In addition, when the in-car unit 101 receives data from the mobile telephone 103 and responds to the data in an odd-numbered slot, the transmission inhibit signal is made high (“H”) during the period from 25 μsec before an even-numbered slot changes to an odd-numbered slot until 25 μsec after the even-numbered slot has changed to the odd-numbered slot. During the period in which data is being transmitted or received in each of an even-numbered slot and an odd-numbered slot, the transmission inhibit signal is made high (including an extension period described later). The reason why the period in which the transmission inhibit signal is made high is set to 25 μsec before and after a slot is that an allowance is made for the 10 μsec.
<Calculation Module 231 >
Next, the calculation module 231 will be explained. The calculation module 231 measures the time required for the communication module 210 to perform wireless communication with the in-car display 102 . That is, the module 231 calculates the time required to transmit and receive data at a specific frequency. The MAC layer module 212 roughly generates two types of frames: one frame requires a response frame (Ack) from the in-car display 102 and the other frame does not require a response frame (Ack) from the in-car display 102 . The calculation module 231 calculates the time required to communicate with the frame or the time required for the frame and the response frame (Ack) to communicated to each other.
FIGS. 5A to 5C are conceptual diagrams of a frame created by the communication module 210 and a response frame (Ack) transmitted by the in-car display 102 in response to the frame.
FIG. 5A is a conceptual diagram of a frame accompanied by a no response frame created by the communication module 210 . FIG. 5A shows an occupation time required for the frame created by the communication module 210 to be transmitted to the in-car display 102 . The calculation module 231 calculates the length of the frame created by the calculation module 231 as an occupation time.
FIG. 5B is a conceptual diagram of a frame accompanied by a response frame (Ack) created by the communication module 210 as described above. FIG. 5B shows an occupation time required for the frame created by the communication module 210 and a response frame (Ack) corresponding to the frame to be transmitted and received. The calculation module 231 calculates as an occupation time the time from when the frame created by the communication module 210 is transmitted to the in-car display 102 until a response frame (Ack) has been received from the in-car display 102 .
FIG. 5C shows a case where a frame and a response frame (Ack) corresponding to the frame in FIG. 5B are transmitted and received in a burst manner three times. In this case, the calculation module 231 regards the time from when a first frame created by the communication module 210 is transmitted until the module 231 receives a response frame (Ack) corresponding to a third frame as an occupation time.
Next, a formula for calculating an occupation time TX TIME by the calculation module 231 will be explained. The occupation time TX TIME is expressed by equation (1). The calculation formula computes the time required for either a frame or a response frame (Ack) to reach the reception side. That is, in the case of FIG. 5B , the time has to be calculated for each of a frame and a response frame (Ack) corresponding to the frame by equation (1):
TX TIME =T — Pre-sig +T — sym *Ceiling((22+8*LENGTH)/(4*RATE))+ T ext (1)
where T — Pre-sig is the total value of a Preamble and a Signal field added by the physical layer 211 at the time of transmission (in μsec), T — sym is the length of one OFDM symbol (in μsec), Ceiling function (a roundup function, that is, in the case of Ceiling (A) (A is a real number), the function rounds up A to the nearest integer), LENGTH is a transmission data length (in bytes), RATE is the transmission rate of PHY (Mbit/s), T — ext is the length of a Signal Extension field (in μsec), and 22 is the number of bits in Service bits and Tail bits added when a PHY layer performs the aforementioned modulation.
<Flowchart for Wireless Communication System>
Next, a communication method used in the wireless communication system configured as described above will be explained with reference to FIG. 6 . FIG. 6 is a flowchart to explain wireless LAN communication and Bluetooth communication performed by the in-car unit 101 .
First, the communication module 220 functioning as a slave carries out a specific connection process with the mobile telephone 103 . By doing this, the communication module 220 is caused to synchronize with the mobile telephone 103 , thereby establishing connection (step S 0 ). That is, the communication module 220 obtains a slot number SN. The connection process includes, for example, an Inquiry process, an Inquiry Scan process, a Page process, and a Page Scan process. Thereafter, the MAC layer module 222 outputs a slot synchronizing signal (slot number SN) and connection information on the communication module 220 to the generation module 230 .
Then, the generation module 230 generates a transmission inhibit signal to the communication module 210 on the basis of the slot synchronizing signal and connection information received from the MAC layer module 222 in step S 0 (S 1 ).
Next, the MAC layer module 212 checks whether there is any frame to be transmitted from the antenna 250 (S 2 ). In step S 2 , if there is a frame to be transmitted (YES in step S 2 ), the calculation module 231 calculates an occupation time for the frame (S 3 ). Specifically, the calculation module 231 calculates an occupation time on the basis of whether to request the PHY transmission rate, frame length, and response frame (Ack) attached to the frame or whether to perform burst transmission at SIFS intervals. Next, the transmission control module 213 checks whether DIFS+back off time have elapsed (S 4 ). In step S 4 , if DIFS+back off time have elapsed, the transmission control module 213 calculates the remaining time from after DIFS+back off time have elapsed until the inhibit period signal generated by the generation module 230 is made high. Then, the transmission control module 213 compares the occupation time required to transmit the frame received from the calculation module 231 with the remaining period (S 5 ).
In step S 5 , if the occupation time is not longer than the remaining time (YES in step S 5 ), the frame created by the MAC layer module 212 is transmitted from the antenna 240 to the in-car display 102 (S 6 ). In step S 5 , if the occupation time is longer than the remaining time (NO in step S 5 ), the transmission control unit 213 does not transmit the frame created by the MAC layer module 212 , measures DIFS+back off time again (S 7 ), and returns to step S 4 .
In step S 4 , if DIFS+back off time have not elapsed (NO in step S 4 ), the transmission control module 213 waits until the time has elapsed.
If in step S 2 there is no frame to be transmitted in the MAC layer module 212 , the transmission control module 213 does not control the communication module 210 .
<Data Transmission and Reception by Wireless Communication System (Part 1)>
Next, the operation of transmitting and receiving data in the wireless communication system of the first embodiment will be explained with reference to FIG. 7 . FIG. 7 depicts time charts to illustrate wireless LAN communication between the in-car unit 101 and in-car display 102 and Bluetooth communication between the in-car unit 101 and mobile telephone 103 . Time is plotted along the horizontal axis. Slot number SN, Bluetooth packet transmission from the mobile telephone 103 , Bluetooth packet transmission from the communication module 220 , transmission inhibit signal, and data (data frame, Ack) exchanged between the communication module 210 and in-car display 102 in wireless LAN communication are enumerated vertically. Suppose the transmission rate in wireless LAN communication is 54 Mbps and the frame length exchanged between the in-car unit 101 and in-car display 102 is 500 bytes. In this case, it is assumed that the length of a response frame (Ack) is 14 bytes and the response frame is transmitted at a transmission rate of 24 Mbps. For the sake of convenience, suppose slot number SN starts with 2 and a pico-net is formed before slot number SN=0 (not shown).
<Before Slot Number SN=0>
First, the in-car unit 101 and mobile telephone 103 are synchronized with each other by a specific connection method and obtain each other's approval. By doing this, a pico-net is formed between the in-car unit 101 and mobile telephone 103 (S 0 ). This enables the MAC layer module 222 to synchronize the mobile telephone 103 with a time slot.
<Slot Numbers SN=2 to SN=3>
After a pico-net is formed, the generation module 230 makes a transmission inhibit signal high during the period from when slot number SN changes from an odd number to an even number until 25 μsec after the odd number has changed to the even number, on the basis of the slot synchronizing signal received from the MAC layer module 222 (S 1 , 25 μsec from the starting point of slot SN=2). Thereafter, the generation module 230 makes the transmission inhibit signal low (“L”) 25 μsec after the odd-numbered slot has changed to an even-numbered one.
Here, suppose the communication module 210 has a frame to be transmitted (YES in step S 2 ). Then, using equation (1), the calculation module 231 calculates an occupation time required to transmit and receive a frame to be transmitted to the in-car display 102 and a response frame (Ack) corresponding to the frame (S 3 ). As a result, in the first embodiment, the occupation time required for a frame to be transmitted is 102 μsec and the occupation time required for the response frame (Ack) to be received is 34 μsec. Adding an SIFS time of 10 μsec to the occupation times gives a total of 146 μsec.
Then, the transmission control module 213 compares the remaining period left until the transmission inhibit signal is made high with the occupation time. Here, the generation module 230 confirms that a Bluetooth packet is not transmitted from the mobile telephone 103 with the timing of slot number SN=2. This allows the generation module 230 to cause the transmission inhibit signal to remain low with the timing of slot number SN=2. As a result, since 146≦1200 μsec (YES in step S 5 ), the transmission control module 213 gives an instruction to transmit a frame (S 6 ). Here, 1200 μsec is obtained as follows: since 2 slots (=625*2 slots)=1250 μsec and since there is a transmission inhibit signal made high for 25 μsec in each of the slots (25*2=50 μsec), this gives a remaining period of 1250−50=1200 μsec. It has been assumed that the time required from when the occupation time and remaining period are calculated until they are compared with each other (in FIG. 7 , the transmission decision period) is, for example, 200 μsec.
<Slot Numbers SN=4 to SN=5>
Next, when the slot number has changed to slot number SN=4, the mobile telephone 103 transmits a Bluetooth packet to the communication module 220 . Accordingly, on the basis of the slot synchronizing signal and connection information received from the MAC layer module 222 , the generation module 230 makes the transmission inhibit signal high during the period from when slot number SN=3 has changed to slot number SN=4 until the mobile telephone 103 has completed the transfer of a Bluetooth packet (S 1 , in FIG. 7 , an extension period in slot SN=4).
Thereafter, suppose the communication module 220 has a frame to be transmitted (YES in step S 2 ). Then, using equation (1), the calculation module 231 calculates an occupation time required to transmit and receive a frame to be transmitted to the in-car display 102 and a response frame (Ack) corresponding to the frame (S 3 ). As a result, the total of the occupation times for the frame, response frame, and SIFS is 146 μsec.
Next, the transmission control module 213 compares the remaining period left until the transmission inhibit signal is made high with the occupation time. Since the mobile telephone 103 has transmitted a Bluetooth packet in slot number SN=4, the generation module 230 predicts that the communication module 220 will transmit a Bluetooth packet in slot number SN=5. Accordingly, the generation module 230 makes the transmission inhibit signal high 25 μsec before the slot number changes to slot number SN=5.
Then, the calculation module 231 calculates the interval during which the transmission inhibit signal is made low in slot number SN=4. As a result, the interval in which the transmission inhibit signal is made low is 234 μsec. The period (transmission decision period) during which it is determined whether a frame created by the communication module 210 should be transmitted is set to 200 μsec. Accordingly, since 146≧34 μsec (NO in step S 5 ), the transmission control module 213 does not transmit the frame created by the MAC layer module 212 , measures DIFS+back off time again (S 7 ), and returns to step S 4 .
Thereafter, when the slot number has changed to slot number SN=5, the communication module 220 transmits a Bluetooth packet to the mobile telephone 103 . Therefore, the generation module 230 makes the transmission inhibit signal high during the period until the Bluetooth packet is transmitted in slot number SN=5. Then, the generation module 230 makes the transmission inhibit signal high 25 μsec before the slot number changes to slot number SN=6 (not shown). If the period in which the transmission inhibit signal made low in slot number SN=4 is short, the generation module 230 may not change the transmission inhibit signal from high to low in slot number SN=4 and cause the transmission inhibit signal to remain high until the data transfer from the communication module 220 in slot number SN=5 has been completed. The same holds true for FIGS. 8 to 11 and FIG. 13 explained below.
<Effects of the First Embodiment>
The wireless communication apparatus and its communication method produce the effects described below.
(1) The degradation of Bluetooth communication can be suppressed.
With the wireless communication apparatus and its commutation method of the first embodiment, even when the communication module 220 functions as a slave, wireless LAN communication between the communication module 210 and in-car display 102 can be stopped in the middle of Bluetooth communication between the communication module 220 and mobile telephone 103 . This prevents the communication module 220 from erroneously receiving the data transmitted by the communication module 210 when the module 220 attempts to receive a Bluetooth packet. That is, in Bluetooth communication, the degradation of communication can be suppressed. Hereinafter, a conventional wireless communication apparatus will be explained.
With a conventional wireless communication apparatus, in Bluetooth communication between the master and a slave mounted in the same LSI or the same unit as a communication module (communication module 210 ) performing wireless LAN communication, the module performing the wireless LAN communication couldn't recognize the reception timing of a Bluetooth packet transmitted from the master. Accordingly, even when the slave was supposed to receive a Bluetooth packet, the module performed wireless LAN communication and caused the problem of erroneously receiving data transmitted and received in the wireless LAN communication.
The problem becomes significant when a Bluetooth communication module and a wireless LAN communication module are mounted on the same LSI as shown in FIG. 1 or when they are mounted in the same unit of a notebook PC or a personal digital assistant. The problem becomes particularly significant when a Bluetooth communication module functions as a slave and a wireless LAN communication module has transmitted a frame. That is, in this case, since the slave receives erroneous data, the reception S/N ratio (Signal to Noise ratio) of the Bluetooth communication packets transmitted from the master is degraded.
With the wireless communication apparatus and its communication method according to the first embodiment, however, the generation module 230 and calculation module 231 are provided and the MAC layer module 222 has the function of outputting a slot synchronizing signal and connection information on Bluetooth communication to the generation module 230 . Specifically, with the wireless communication apparatus and its communication method according to the first embodiment, the generation module 230 recognizes slot number SN on the basis of the slot synchronizing signal received from the MAC layer module 222 . That is, the generation module 230 can recognize the timing with which an odd-numbered slot switches to an even-numbered slot. Accordingly, the generation module 230 can recognize the timing with which the mobile telephone 103 transmits a Bluetooth packet, regardless of whether or not a Bluetooth packet is transmitted. This enables the generation module 230 to make the transmission inhibit signal high 25 μsec before and after an odd-numbered slot switches to an even-numbered slot.
The same holds true for the reverse case. Specifically, the generation module 230 can recognize the timing with which an even-numbered slot switches to an odd-numbered slot. Then, when there is a Bluetooth packet from the mobile telephone 103 in an even-numbered slot, it is predicted that the communication module 220 will transmit a Bluetooth packet.
Accordingly, the generation module 230 can make the transmission inhibit signal high 25 μsec before and after an even-numbered slot switches to an odd-numbered slot.
Furthermore, the generation module 230 can actually recognize the transmission and reception of a Bluetooth packet in each slot on the basis of connection information on Bluetooth communication received from the MAC layer module 222 . As a result, besides the transmission inhibit signal made high 25 μsec before and after the boundary between slots, an extension period as explained in FIG. 7 can be added as needed.
Then, the generation module 230 outputs the transmission inhibit signal to the MAC layer module 212 . The communication module 220 then outputs connection information to the MAC layer module 212 . The calculation module 231 outputs the occupation time to the MAC layer module 212 . Therefore, the transmission control module 213 can compare the occupation time with the remaining time and avoid performing wireless LAN communication (or the transmission of a frame by the communication module 210 ) when receiving a Bluetooth packet from the mobile telephone 103 . In other words, even when asynchronous packets are being transmitted and received by the ACL link method in the pico-net, use of the aforementioned configuration and its functions enables wireless LAN communication to be performed without interfering with Bluetooth communication.
As described above, the first embodiment can suppress the degradation of the communication performance of Bluetooth communication.
[Second Embodiment]
Next, a second embodiment of the invention will be explained. The second embodiment is such that Bluetooth packets transmitted and received in the first embodiment in a pico-net are DM 3 packets. Since the configuration of a wireless communication apparatus 200 of the second embodiment and the function of the configuration are the same as those of the first embodiment, an explanation of them will be omitted. As in the first embodiment, the communication module 220 functions as a slave to the mobile telephone 103 .
<Data Transmission and Reception in Wireless Communication System (Part 2)>
The operation of transmitting and receiving data in the wireless communication system of the second embodiment will be explained with reference to FIG. 8 . FIG. 8 depicts time charts to illustrate wireless LAN communication between the in-car unit 101 and in-car display 102 and Bluetooth communication between the in-car unit 101 and mobile telephone 103 . Time is plotted along the horizontal axis. Slot number SN, Bluetooth packet transmission from the mobile telephone 103 , Bluetooth packet transmission from the communication module 220 , transmission inhibit signal, and data (data frame, Ack) exchanged between the communication module 210 and in-car display 102 in wireless LAN communication are enumerated vertically. Suppose the transmission rate in wireless LAN communication is 54 Mbps and the frame length exchanged between the in-car unit 101 and in-car display 102 is 500 bytes. In this case, it is assumed that the length of a response frame (Ack) is 14 bytes and the response frame is transmitted at a transmission rate of 24 Mbps. For the sake of convenience, suppose slot number SN starts with 2 and a pico-net will be formed before slot number SN=0 (not shown). An explanation of the same operation as in the first embodiment will be omitted.
<Slot Numbers SN 4 to SN 6 >
The mobile telephone 103 transmits a Bluetooth packet to the communication module 220 with the timing of slot number SN=4. As described above, in the second embodiment, the mobile telephone 103 transmits DM 3 packets. Therefore, the mobile telephone 103 transmits DM 3 packets at the same fixed frequency in the period of slot numbers SN=4 to SN=6.
Accordingly, on the basis of the slot synchronizing signal and connection information received from the MAC layer module 222 , the generation module 230 makes the transmission inhibit signal high during the period from when the slot number is changed from slot number SN=3 to slot number SN=4 until the transfer of Bluetooth packets from the mobile telephone 103 is completed (S 1 , in FIG. 8 , the extension period shown by slots SN=4 to SN=6).
Thereafter, suppose the communication module 210 has a frame to be transmitted (YES in step S 2 ). Then, using equation (1), the calculation module 231 calculates an occupation time required to transmit and receive a frame to be transmitted to the in-car display 102 and a response frame (Ack) corresponding to the frame (S 3 ). As a result, the total of the occupation times for the frame, response frame, and SIFS is 146 μsec.
Next, the transmission control module 213 compares the remaining period left until the transmission inhibit signal is made high with the occupation time. Here, the transmission control module 213 predicts that the communication module 220 will transmit a Bluetooth packet with the timing of slot number SN=7 in response to the Bluetooth packet transmitted by the mobile telephone 103 in the period of slot numbers SN=4 to SN=6. Accordingly, the generation module 230 makes the transmission inhibit signal high 25 μsec before the slot number changes to slot number SN=7. Then, the calculation module 231 calculates the interval during which the transmission inhibit signal is made low in slot number SN=6. As a result, the interval in which the transmission inhibit signal is made low is 224 μsec. The period (transmission decision period) during which it is determined whether the frame created by the communication module 210 should be transmitted is set to 200 μsec. Accordingly, since 146≧24 μsec (NO in step S 5 ), the transmission control module 213 does not transmit the frame created by the MAC layer module 212 , measures DIFS+back off time again (S 7 ), and returns to step S 4 (S 4 ).
Thereafter, when the slot number has changed to slot number SN=7, the communication module 220 transmits a Bluetooth packet to the mobile telephone 103 . Therefore, the generation module 230 makes the transmission inhibit signal high during the period until the Bluetooth packet is transmitted in slot number SN=7. Then, the generation module 230 makes the transmission inhibit signal high 25 μsec before the slot number changes to slot number SN=8 (not shown).
[Effect of the Second Embodiment]
The wireless communication apparatus and its communication method according to the second embodiment can also produce the same effect as described in item (1). Specifically, since the wireless communication apparatus of the second embodiment is the same as that of the first embodiment in configuration and function, even when packets transmitted and received in the pico-net are changed from DM 1 to DM 3 , the same effect can be obtained. That is, the communication module 210 can perform wireless LAN communication, while suppressing the degradation of the communication performance of Bluetooth communication.
[Third Embodiment]
Next, a wireless communication apparatus and its communication method according to a third embodiment of the invention will be explained. The third embodiment is such that a communication module 220 and a mobile telephone 103 in a pico-net are connected to each other with a Synchronous Connection Oriented (SCO) link. In Bluetooth communication in the pico-net, HV 2 packets are used. The HV 2 packets are transmitted and received at intervals of 3 slots. That is, the transmission and reception of HV 2 packets between the communication module 220 and the mobile telephone 103 are performed at intervals of 1.25 msec (625 μsec*2). In other words, each of the mobile telephone 103 and communication module 220 transmits HV 2 packets at intervals of 4 slots. The SCO link, which is a Point to Point link between a master and a specific slave, is used in telephone quality sound symmetric 64-Kbps communication. Even if a packet cannot be transmitted in the middle of communication due to degradation of the transmission line conditions in voice call using the SCO link, the same packet will not be transmitted again. Since the configuration of the wireless communication apparatus 200 of the third embodiment and the function of the configuration are the same as those of the first embodiment, an explanation of them will be omitted. In addition, as in the first embodiment, the communication module 220 functions as a slave to the mobile telephone 103 .
<Data Transmission and Reception in Wireless Communication System (Part 3)>
The operation of transmitting and receiving data in the wireless communication system of the third embodiment will be explained with reference to FIG. 9 . FIG. 9 depicts time charts to illustrate wireless LAN communication between the in-car unit 101 and in-car display 102 and Bluetooth communication between the in-car unit 101 and mobile telephone 103 . Time is plotted along the horizontal axis. Slot number SN, Bluetooth packet transmission from the mobile telephone 103 , Bluetooth packet transmission from the communication module 220 , transmission inhibit signal, and data (data frame, Ack) exchanged between the communication module 210 and in-car display 102 in wireless LAN communication are enumerated vertically. Suppose the transmission rate in wireless LAN communication is 54 Mbps and the frame length exchanged between the in-car unit 101 and in-car display 102 is 500 bytes. In this case, it is assumed that the length of a response frame (Ack) is 14 bytes and the response frame is transmitted at a transmission rate of 24 Mbps. For the sake of convenience, suppose slot number SN starts with 2 and a pico-net is formed before slot number SN=0 (not shown). An explanation of the same operations as in the first and second embodiments will be omitted.
<Slot Numbers SN 2 to SN 5 >
After a pico-net has been formed, when the slot number has changed to slot number SN=2, the mobile telephone 103 transmits a Bluetooth packet to the communication module 220 . Accordingly, the generation module 230 receives from the MAC layer module 222 the slot synchronizing signal, connection information, link method (in this case, SCO link) information, and Bluetooth packet (in this case, HV 2 packet) information. For these pieces of information, the generation module 230 makes the transmission inhibit signal high during the period from when slot number SN=1 (not shown) changes to slot number SN=2 until the transfer of a Bluetooth packet from the mobile telephone 103 is completed (S 1 , in FIG. 9 , the extension period in slot SN=2).
Since the mobile telephone 103 has transmitted a Bluetooth packet in slot number SN=2, the generation module 230 predicts that the communication module 220 will transmit a Bluetooth packet in slot number SN=3. From this, the generation module 230 makes the transmission inhibit signal high 25 μsec before the slot number changes to slot number SN=3. Thereafter, when the slot number has changed to slot number SN=3, the communication module 220 transmits a Bluetooth packet to the mobile telephone 103 .
Accordingly, the generation module 230 makes the transmission inhibit signal low during the period until the transmission of the Bluetooth packet is completed in slot number SN=3. Thereafter, when the communication module 220 has transmitted the Bluetooth packet, the generation module 230 makes the transmission inhibit signal low.
Since the MAC layer module 222 has informed the generation module 230 of connection by the SCO link, the module 230 causes the transmission inhibit signal to remain low during the period of slot numbers SN=4 and SN=5. Here, suppose the communication module 210 has a frame to be transmitted (YES in step S 2 ).
Then, using equation (1), the calculation module 231 calculates an occupation time required to transmit and receive a frame to be transmitted to the in-car display 102 and a response frame (Ack) corresponding to the frame (S 3 ). As a result, in the third embodiment, the occupation time required to transmit a frame is 102 μsec and the occupation time required to receive the response frame is 34 μsec. Adding the SIFS time (10 μsec) to the occupation times gives a total of 146 μsec.
Then, the transmission control module 213 compares the remaining time left until the transmission inhibit signal is made high with the occupation time. Since the comparison result has shown that 146≦1484 μsec (YES in step S 5 ), the transmission control module 213 gives an instruction to transmit a frame (S 6 ).
Here, 1484 μsec is obtained as follows: since 3 slots (=625*3 slots, slot numbers SN=3 to SN=5)=1875 μsec and since the transmission inhibit signal made high in slot number SN=5 lasts for 25 μsec and the time required to transmit a frame in slot number SN=3 is 366 μsec, the remaining period is 1875−(25+366)=1484 μsec. It is assumed that the time from when the occupation time and remaining time are calculated until they are compared (in FIG. 9 , the transmission decision period) is, for example, 200 μsec.
Thereafter, in slot numbers SN=6 and SN=7, HV 2 packets are transmitted and received. Since the operation of the configuration of the wireless communication apparatus 200 in slot numbers SN=6 and SN=7 is the same as in slot numbers SN=4 and SN=5 of FIG. 7 explained in the first embodiment, an explanation of the operation will be omitted.
<Effect of the Third Embodiment>
The wireless communication apparatus and its communication method according to the third embodiment can provide the same effect as described in item (1). The wireless communication apparatus and its communication method according to the third embodiment use the SCO link differing in communication method from that in the pico-net of the first and second embodiments. In this case too, as the MAC layer module 222 outputs to the generation module 230 the slot synchronizing signal, connection information, link method (in this case, SCO link) information, and Bluetooth packet (in this case, HV 2 packet) information, the generation module 230 can predict the timing with which the mobile telephone 103 will transmit a Bluetooth packet, that is, the timing with which the slot will be changed to an even-numbered slot. That is, even when Bluetooth packets are transmitted and received periodically as in the SCO link, the timing with which transmission will be performed in the period is predicted and the transmission inhibit signal is made high with the predicted timing, which enables Bluetooth communication and wireless LAN communication to be prevented from interfering with each other. Accordingly, with the wireless communication apparatus and its communication method according to the third embodiment, even if transmission and reception are performed by a different link method, the communication module 210 can perform wireless LAN communication, while suppressing the degradation of the communication performance of Bluetooth communication.
[Modification]
Next, a wireless communication apparatus and its communication method according to a modification of the third embodiment will be explained. The wireless communication apparatus of the modification makes enhanced Synchronous Connection Oriented (eSCO) link connection in a pico-net. That is, the HV 2 packets are transmitted in such a manner that three packets are connected in burst form. In this case, too, the same fixed frequency is used in a period during which consecutive HV 2 packets are transmitted.
Since the configuration of the wireless communication apparatus and the function of the configuration according to the modification are the same as those of the first embodiment, an explanation of them will be omitted. In addition, the communication module 220 functions as a slave to the mobile telephone 103 as in the first embodiment.
<Data Transmission and Reception in Wireless Communication System (Part 4)>
The operation of transmitting and receiving data in the wireless communication system of the modification will be explained with reference to FIG. 10 . FIG. 10 depicts time charts to illustrate wireless LAN communication between the in-car unit 101 and in-car display 102 and Bluetooth communication between the in-car unit 101 and mobile telephone 103 . Time is plotted along the horizontal axis. Slot number SN, Bluetooth packet transmission from the mobile telephone 103 , Bluetooth packet transmission from the communication module 220 , transmission inhibit signal, and data (data frame, Ack) exchanged between the communication module 210 and in-car display 102 in wireless LAN communication are enumerated vertically. Suppose the transmission rate in wireless LAN communication is 54 Mbps and the frame length exchanged between the in-car unit 101 and in-car display 102 is 500 bytes. In this case, it is assumed that the length of a response frame (Ack) is 14 bytes and the response frame is transmitted at a transmission rate of 24 Mbps. For the sake of convenience, suppose slot number SN starts with 2 and a pico-net is formed before slot number SN=0 (not shown). An explanation of the same operations as in the first to third embodiments will be omitted.
<Slot Numbers SN=2 to SN=15>
The mobile telephone 103 transmits a Bluetooth packet to the communication module 220 with the timing of slot number SN=2. As described above, in the modification, the mobile telephone 103 transmits HV 2 packets by the eSCO link method. Accordingly, the mobile telephone 103 transmits HV 2 packets in burst form at the same fixed frequency during the period of slot numbers SN=2 to SN=4. Therefore, on the basis of the slot synchronizing signal, connection information, and Bluetooth packet (in this case, HV 2 packet) information received from the MAC layer module 222 , the generation module 230 makes the transmission inhibit signal high during the period from when slot number SN=2 starts until the transfer of Bluetooth packets from the mobile telephone 103 is completed in slot number SN=4 (S 1 , in FIG. 10 , the extension period from slot SN=2 to slot SN=4).
Thereafter, when having received connection information about the completion of the transmission of HV 2 packets from the mobile telephone 103 from the MAC layer module 222 , the generation module 230 outputs a low transmission inhibit signal (S 1 ).
Next, since the mobile telephone 103 has transmitted Bluetooth packets in the slot numbers SN=2 to SN=4, the generation module 230 predicts that the communication module 220 will transmit a Bluetooth packet in slot number SN=5.
Accordingly, the generation module 230 makes the transmission inhibit signal high 25 μsec before the slot number changes to slot number SN=5. Thereafter, when the slot number has changed to slot number SN=5, the communication module 220 transmits a Bluetooth packet to the mobile telephone 103 . The generation module 230 has received link method information from the MAC layer module 222 . Therefore, the generation module 230 makes the transmission inhibit signal high until the transmission of Bluetooth packets is completed (S 1 , in FIG. 10 , the extension period shown by slot numbers SN=5 to SN=7).
Thereafter, on the basis of connection information from the MAC layer module 222 , the generation module 230 makes the transmission inhibit signal low (S 1 ). Since having recognized that the eSCO link connection is in progress, the generation module 230 makes the transmission inhibit signal low during the period of slot numbers SN=8 and SN=9 adjacent to slot number SN=7 in which the transmission of HV 2 packets by the communication module 210 has been completed, that is, in a period of 1.25 msec.
In the modification, too, since frames are transmitted and received in wireless LAN communication (S 2 ), the same transmission control as in the above embodiments is performed in the period during which the transmission inhibit signal is made low.
Since the operations in slot number SN=10 and forward are the same as those in slot number SN=4 and forward in FIG. 8 in the second embodiment, an explanation of them will be omitted.
<Effect of Modification>
The wireless communication apparatus and its communication method according to the modification can provide the same effect as described in item (1). The wireless communication apparatus and its communication method according to the modification use an eSCO link differing in communication method from that in the pico-net of the first to third embodiments. In this case too, the MAC layer module 222 outputs to the generation module 230 the slot synchronizing signal, connection information, link method (in this case, SCO link) information, and Bluetooth packet (in this case, HV 2 packet) information, the generation module 230 can predict the timing with which the mobile telephone 103 will transmit a Bluetooth packet, that is, the timing with which the slot will be changed to an even-numbered slot.
Accordingly, with the wireless communication apparatus and its communication method according to the modification, even if transmission and reception are performed by a different link method, the communication module 210 can perform wireless LAN communication, while suppressing the degradation of the communication performance of Bluetooth communication. That is, even by the eSCO link method, the same effect as described in item (1) can be obtained.
[Fourth Embodiment]
Next, a wireless communication apparatus and its communication method according to a fourth embodiment of the invention will be explained. The wireless communication apparatus of the fourth embodiment is such that the communication module 220 functions as a master to the mobile telephone 103 in the first embodiment. In the fourth embodiment, the communication module 210 and the communication module 220 functioning as a master are provided in the same LSI or in the same unit. That is, in the fourth embodiment, the mobile telephone 103 functions as a slave to the communication module 220 . Accordingly, when a pico-net including the communication module 220 and mobile telephone 103 is established, the specific connection process is carried out with the communication module 220 as the master. On the basis of the internal clock of the MAC layer module 222 , the mobile telephone 103 synchronizes the MAC layer module 222 with a time slot. With this synchronization, connection information and the slot synchronizing signal held in the master are supplied from the MAC layer module 222 to the generation module 230 . As a result, the generation module 230 can generate a transmission inhibit signal.
As described above, since the communication module 210 and the communication module 220 functioning as the master are provided in the same LSI or in the same unit, the generation module 230 can be informed in advance by the MAC layer module 222 whether there is any Bluetooth packet to be transmitted by the communication module 220 . Accordingly, if the generation module 230 is informed in advance that there is no Bluetooth packet to be transmitted by the communication module 220 , there is no need to make the transmission inhibit signal high with the timing of an odd-numbered slot changing to an even-numbered slot. Hereinafter, in the fourth embodiment, an explanation will be given on the assumption that the generation module 230 cannot be informed in advance as to whether there is any Bluetooth packet to be transmitted by the communication module 220 .
Since the configuration of the wireless communication apparatus 200 and the function of the configuration are the same as those of the first to third embodiments, except for what has been described above, an explanation of them will be omitted. Although data transmission and reception using DM 1 packets will be explained in the wireless communication apparatus and its communication method of the fourth embodiment, DM 3 packets, DM 5 packets, or HV 2 packets may be used instead of DM 1 packets.
<Data Transmission and Reception in Wireless Communication System (Part 5)>
Next, the operation of transmitting and receiving data in the wireless communication system of the fourth embodiment will be explained with reference to FIG. 11 . FIG. 11 depicts time charts to illustrate wireless LAN communication between the in-car unit 101 and in-car display 102 and Bluetooth communication between the in-car unit 101 and mobile telephone 103 . Time is plotted along the horizontal axis. Slot number SN, Bluetooth packet transmission from the mobile telephone 103 , Bluetooth packet transmission from the communication module 220 , transmission inhibit signal, and data (data frame, Ack) exchanged between the communication module 210 and in-car display 102 in wireless LAN communication are enumerated vertically. Suppose the transmission rate in wireless LAN communication is 54 Mbps and the frame length exchanged between the in-car unit 101 and in-car display 102 is 500 bytes. In this case, it is assumed that the length of a response frame (Ack) is 14 bytes and the response frame is transmitted at a transmission rate of 24 Mbps. For the sake of convenience, suppose slot number SN starts with 2 and a pico-net is formed before slot number SN=0 (not shown). An explanation of the same operations as in the first to third embodiments will be omitted.
<Slot Numbers SN 2 to SN 5 >
As described above, after a pico-net has been formed, the generation module 230 cannot be informed in advance that there is no Bluetooth packet to be transmitted by the communication module 220 . Accordingly, on the basis of the slot synchronizing signal received from the MAC layer module 222 , the generation module 230 makes the transmission inhibit signal high during the period from when slot number SN changes from SN=1 (not shown) to SN=2 until 25 μsec after the slot number has changed to SN=2 (S 1 , in FIG. 11 , 25 μsec from the starting point of slot SN=2).
If the generation module 230 can be informed in advance that there is no Bluetooth packet to be transmitted by the communication module 220 , the module 230 may make low the transmission inhibit signal to be output to the transmission control module 213 in slot number SN=2.
Thereafter, the occupation time calculation module 231 and generation module 230 carry out the same operations as described in FIG. 7 of the first embodiment in the period of slot numbers SN=2 and SN=3 (SN=2 and SN=3 in FIG. 7 ).
Then, on the basis of the slot synchronizing signal supplied from the MAC layer module 220 , the generation module 230 outputs a high transmission inhibit signal to the transmission control module 213 25 μsec before slot number SN=3 changes to slot number SN=4 (S 1 ).
Then, the communication module 220 transmits a Bluetooth packet with the timing of slot number SN=4. Therefore, on connection information from the MAC layer module 222 , the generation module 230 causes the transmission inhibit signal to remain high.
If the generation module 230 has been informed by the MAC layer module 222 before the slot number was changed to slot number SN=4 that there is a Bluetooth packet to be transmitted by the communication module 220 , the inhibit signal generation module 230 outputs a high transmission inhibit signal to the transmission control module 213 , regardless of connection information from the MAC layer module 222 .
Then, after the transmission of a Bluetooth packet by the communication module 220 has been completed, the generation module 230 makes the transmission inhibit signal low.
Next, since the communication module 220 has transmitted a Bluetooth packet in slot number SN=4, the generation module 230 predicts that the mobile telephone 103 will transmit a Bluetooth packet in slot number SN=5.
Accordingly, the generation module 230 makes the transmission inhibit signal high 25 μsec before the slot number changes to slot number SN=5.
Thereafter, the operations explained in FIG. 7 are carried out by the calculation module 231 and transmission control module 213 (transmission decision in slot number SN=4 in FIG. 7 ). When the slot number has changed to slot number SN=5, the mobile telephone 103 transmits a Bluetooth packet to the communication module 220 . Therefore, the generation module 230 makes the transmission inhibit signal high during the period until the Bluetooth packet is transmitted in slot number SN=5.
<Effect of the Fourth Embodiment>
The wireless communication apparatus and its communication method according to the fourth embodiment can also produce the same effect as described in item (1). Specifically, when the communication module 220 functions as a master to the mobile telephone 103 , the MAC layer module 222 informs the generation module 230 of the slot synchronizing signal, connection information, and the presence or absence of a Bluetooth packet to be transmitted, which enables the generation module 230 to generate a transmission inhibit signal at a suitable timing. This makes it possible to avoid the problem of transmitting and receiving data in wireless LAN communication in the middle of Bluetooth communication.
[Fifth Embodiment]
Next, a wireless communication apparatus and its communication method according to a fifth embodiment of the invention will be explained. FIG. 12 is a block diagram of a wireless communication apparatus 1000 of the fifth embodiment. As shown in FIG. 12 , the wireless communication apparatus 1000 included in the in-car unit 101 is such that the communication module 220 functioning as a Bluetooth communication module in FIG. 1 is omitted and a communication module (in FIG. 12 , a Time Division Multiple Access (TDMA) wireless communication module 1020 ) which performs time-division communication is provided. In the wireless communication apparatus 1000 , the TDMA wireless communication module 1020 (in this case, assumed to be a mobile unit) and a time-division communication terminal (assumed to be a TDMA base station, not shown) constitute a wireless communication system which performs time-division communication, and the communication module 210 and in-car display 102 constitute a wireless LAN system as in the first to fourth embodiments.
<Configuration of in-Car Unit 101 >
The configuration of the in-car unit 101 (wireless communication apparatus 1000 ) according to the fifth embodiment will be explained, centering on the members differing from those in the first to fourth embodiments. The wireless communication apparatus 1000 includes the TDMA wireless communication module 1020 as described above. The TDMA wireless communication module 1020 includes a physical layer module 1021 and a MAC layer module 1022 . Each of the physical layer module 1021 and MAC layer module 1022 has a function for performing time-division communication.
<Physical Layer Module 1021 >
The physical layer module 1021 subjects a reception signal (analog signal) supplied from the antenna 240 to A/D converter, thereby obtaining a digital signal. The module 1021 further demodulates the digital signal, obtaining a reception frame. Then, the module 1021 outputs the obtained reception frame to the MAC layer module 1022 .
<MAC Layer Module 1022 >
The MAC layer module 1022 performs specific access control complying with time-division communication. That is, on the basis of the internal clock of the mobile telephone 103 , the MAC layer module 1022 synchronizes the mobile telephone 103 with a time slot. Specifically, the MAC layer module 1022 recognizes each of the timing of transmitting its own data (up-link timing) and the timing of transmitting data by the mobile telephone 103 (down-link timing). Then, the MAC layer module 1022 outputs the transmission timing and connection information on the mobile telephone 103 to the generation module 230 .
<Data Transmission and Reception in Wireless Communication System (Part 6)>
Next, the operation of transmitting and receiving data in the wireless communication system of the fifth embodiment will be explained with reference to FIG. 13 . FIG. 13 depicts time charts to illustrate wireless LAN communication between the in-car unit 101 and in-car display 102 and communication between the in-car unit 101 and mobile telephone 103 by time-division multiple access. Time is plotted along the horizontal axis. Time slot (Up Link period or Down Link period), data transmission from the mobile telephone 103 , data transmission from the communication module 1020 which provides time-division multiple access, transmission inhibit signal, and data (data frame, Ack) exchanged between the communication module 210 and in-car display 102 in wireless LAN communication are enumerated vertically.
Suppose the transmission rate in wireless LAN communication is 54 Mbps and the frame length exchanged between the in-car unit 101 and in-car display 102 is 500 bytes. In this case, it is assumed that the length of a response frame (Ack) is 14 bytes and the response frame is transmitted at a transmission rate of 24 Mbps. Suppose time-division multiple access is established between the communication module 1020 and mobile telephone 103 before time t 0 (not shown). The interval between time slots (Down Link periods, Up Link periods) is 625 μsec as in the first to fourth embodiments.
As shown in FIG. 13 , the period of time t 0 to t 1 and the period of time t 2 to t 3 (Down Link periods) correspond to slot numbers SN=2 and SN=4 of FIG. 7 in the first embodiment, respectively. The period of time t 1 to t 2 and the period of time t 3 to t 4 (Up Link periods) correspond to slot numbers SN=3 and SN=4, respectively. In the period of time t 2 to t 3 (Down Link period), a time-division communication terminal (TDMA base station) transfers data to the communication module 220 . In the period of time t 3 to t 4 (Up Link period), the communication module 220 transfers data to an unshown time-division communication terminal (TDMA base station).
Accordingly, as in FIG. 7 , on the basis of the time slot and connection information received from the MAC layer module 1022 , the generation module 230 outputs a transmission inhibit signal to the MAC layer module 212 . Since the remaining operation is the same as described above, an explanation of it will be omitted.
<Effect of the Fifth Embodiment>
In the wireless communication apparatus and its communication method according to the fifth embodiment, the functions of the individual members included in the wireless communication apparatus of the first to fourth embodiments may be used without any modification. That is, the communication module mounted on the same LSI or in the same unit as the communication module (communication module 210 ) which performs wireless LAN communication is not limited to a Bluetooth module. Any suitable module may be used as the communication module to produce the same effect as described in item (1), provided that the module performs time-division communication. The fifth embodiment may be applied not only to the wireless communication apparatus and its communication method according to the first embodiment but also to the wireless communication apparatus and its communication method according to the second and third embodiments.
While in the fifth embodiment the TDMA wireless communication module 1020 is caused to function as a mobile unit and a time-division communication terminal (not shown) is caused to function as a base station, the former may be used as a base station and the latter as a mobile unit. In this case, the same operation as in the fourth embodiment is carried out.
The wireless communication apparatus and its communication method according to the first to fifth embodiments and the individual processing modules constituting the wireless communication apparatus and its communication method according to the modification may be realized by analog or digital circuits. Furthermore, they may be realized by software or the like run by a central processing unit (CPU).
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. | A wireless communication apparatus includes a first module, a second module, an inhibit module, a calculation module, and a control module. The first module constitutes a first system. The first system transmits and receives first data to and from a first device. The second module constitutes a second system. The second system transmits and receives second data to and from a second device in each interval time-divided with determined transmission timing. The inhibit module generates inhibit periods for preventing the first module from communicating by use of the first data. The calculation module calculates an occupation time required for the transmission and reception of the first data. The control module compares the period between the inhibit periods adjacent to one another with the occupation time and, according to the comparison result, instructs the first device to stop or delay the transmission of the first data. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to a method for tinting a hydrophilic polymer employing a reactive dye.
Contact lenses of the "soft" variety are generally formed from covalently crosslinked hydrophilic polymers which are based on hydrophilic derivatives of acrylic or methacrylic acid, e.g., their hydrophilic esters or amides, hydrophilic vinylic polymers such as vinylpyrrolidone, and the like. In their hydrated state, these polymers are referred to as hydrogels, coherent three-dimensional polymer structures or networks which are capable of absorbing large quantities of water without dissolving and of transporting oxygen. In addition to hydrophilic monomer(s), the preparation of hydrophilic polymers used in the manufacture of soft contact lenses also utilizes minor amounts of less hydrophilic, and even hydrophobic, monomer(s) to confer mechanical strength and other useful properties.
Contact lenses formed from hydrophilic polymers can be tinted for cosmetic appearance as well as to reduce light transmission thereby providing the wearer with greater visual comfort. A variety of methods have been disclosed for tinting such lenses. According to U.S. Pat. No. 4,891,046, the contents of which are incorporated by reference herein, a hydrophilic contact lens is tinted with a dichlorotriazine dye in a two step procedure. In the first step of the procedure, the lens, which is formed from a hydrophilic polymer obtained by the peroxide-initiated polymerization of a polymer-forming composition containing a hydroxyl group-containing acrylic ester monomer, e.g., hydroxyethyl methacrylate (HEMA), and N-vinylpyrrolidone, is immersed in an aqueous solution of dichlorotriazine dye maintained at an approximately neutral pH which reduces to near zero the rate at which the dye hydrolyzes or reacts with the hydroxyl groups of the acrylic ester monomer. Under these conditions, the dye diffuses into the lens. Thereafter, the dye-impregnated lens is immersed in an aqueous solution of base which catalyzes the reaction of the dye with the hydroxyl groups in the polymer backbone.
The hydrophilic contact lens tinting method of U.S. Pat. No. 4,891,046 is intended to be practiced on a finished lens and incorporates the dichlorotriazine dye in the hydrophilic polymer constituting the lens body in an operation which is entirely distinct from that used for forming the polymer.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a method for tinting a hydrophilic polymer with a reactive dye.
It is a particular object of the invention to provide a method for tinting a contact lens fabricated from a hydrophilic polymer in which a reactive dye is incorporated in the hydrophilic polymer during its formation.
It is yet another object of the invention to manufacture a tinted hydrophilic contact lens from a hydrophilic polymer-forming composition which includes a reactive dye and a polymerization initiator other than a peroxide under spin casting conditions whereby the lens is simultaneously formed and the dye incorporated therein and subsequently hydrating the lens in an aqueous solution of base which catalyzes the reaction of the dye with the polymer.
In keeping with these and other objects of the invention, a method is provided for tinting a hydrophilic polymer which comprises:
a) subjecting a hydrophilic polymer-forming composition comprising (i) at least one hydrophilic ethylenically unsaturated monomer, (ii) a reactive dye and (iii) a polymerization initiator which does not chemically affect the reactive dye to polymer forming conditions to provide a hydrophilic polymer in which the reactive dye is substantially uniformly incorporated therein; and,
b) contacting the polymer with an aqueous solution of a base which catalyzes the reaction between the polymer and the reactive dye, the reactive dye thereby becoming covalently bound to the polymer.
Unlike the tinting method of U.S. Pat. No. 4,891,046, supra, the reactive dye employed in the tinting method of this invention is incorporated into a hydrophilic polymer while the polymer is being formed. Thus, the present tinting method obviates the need for a separate manufacturing operation wherein a pre-formed hydrophilic polymer is immersed in an aqueous solution of reactive dye.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hydrophilic polymers which can be tinted by the method of this invention constitute a well-known class of synthetic resins derived from a polymerizable ethylenically unsaturated hydrophilic monomer, usually with one or more other comonomers and with a crosslinking monomer as described, inter alia, in U.S. Pat. Nos. 2,976,576; 3,220,960; 3,822,089; 4,123,407; 4,208,364; 4,208,365; and, 4,517,139, the contents of which are incorporated by reference herein. Suitable hydrophilic monomers include hydroxy lower alkyl acrylates or methacrylates, hydroxy lower alkoxy lower alkyl acrylates or methacrylates, and alkoxy lower alkyl acrylates or methacrylates. A "lower alkyl" or "lower alkoxy" is herein defined to mean an alkyl or alkoxy of about five carbon atoms or less. Specific hydrophilic monomers include hydroxyethyl methacrylate (HEMA), hydroxyethyl acrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, butanediol monomethacrylate monoacrylate and vinylpyrrolidone. The hydroxyalkyl acrylates and methacrylates, particularly 2-hydroxyethyl methacrylate are generally preferred.
Useful comonomers generally included in the polymer-forming composition include the alkyl acrylates or methacrylates such as methyl methacrylate, ethyl acrylate, isopropyl acrylate, propyl acrylate, butyl acrylate, secbutyl acrylate, pentyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, sec-butyl methacrylate, pentyl methacrylate, cyclohexyl methacrylate and fluorinated acrylates and methacrylates. Examples of aryl acrylates and methacrylates are phenyl acrylate, phenyl methacrylate, etc. An example of an alkyl or aryl vinyl ether is ethyl vinyl ether and phenyl vinyl ether.
While the hydrophilic polymers can be crosslinked by exposure to energy, e.g., heat or actinic radiation, the more common practice is to achieve covalent crosslinking through the use of a diethylenically unsaturated crosslinking monomer. Examples of such crosslinking monomers include diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, butylene glycol dimethacrylate, neopentyl glycol dimethacrylate, diethylene glycol bisallylcarbonate, 2,3-epoxy propyl methacrylate, divinyl benzene, ethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,3-butylene dimethacrylate, 1,3-butylene dimethacrylate, 1,4-butylene dimethacrylate, propylene glycol diacrylate, propylene glycol dimethacrylate, dipropylene glycol dimethacrylate, diethylene glycol diacrylate, dipropylene glycol diacrylate and trimethylol propane trimethacrylate.
Where the hydrophilic polymer is intended to be used in the manufacture of a contact lens, the polymer-forming composition will typically contain from about 50 to about 95 weight percent hydrophilic monomer, from about 1 to about 40 weight percent comonomer and from about 0.2 to about 2.5 weight percent crosslinking monomer.
The polymerization initiator selected for inclusion in the hydrophilic polymer-forming composition must be non-reactive for the reactive dye component. This requirement necessarily excludes the peroxide-type polymerization initiators which oxidize (bleach) reactive dyes. Photoinitiators constitute one class of useful polymerization initiator which, unlike the peroxides, do not affect the reactive dye. Photoinitiators are well known and are described, e.g., in Chapter II of "Photochemistry" by Calvert and Pitts, John Wiley & Sons (1966). The preferred photoinitiators are those which facilitate polymerization when the polymer-forming composition is irradiated with UV light. Representative examples of such initiators include azo type compounds such as azobisisobutyronitrile, 2,2'-azobis-(2,4-dimethylvaleronitrile) and 2,2'-azobis-(2,4-dimethyl-4-methoxyvaleronitrile), acyloin and derivatives thereof such as benzoin, benzoin methyl ether, n-benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether and α-methylbenzoin; diketones such as benzil and diacetyl, etc.; ketones such as acetophenone, α, α, α-trichloroacetophenone, α, α, α-tribromoacetophenone, α, α-diethoxyacetophenone DEAP), 2-hydroxy-2-methyl-1-phenyl-1-propanone, o-nitro-α, α, α-tribromoacetophenone, benzophenone and p,p'-tetramethyldiaminobenzophenone; α-acyloxime esters such as benzil-(O-ethoxycarbonyl)-α-monoxime; ketone/amine combinations such as benzophenone/N-methyldiethanolamine, benzophenone/tributylamine and benzophenone/Michler's ketone; and benzilketals such as benzildimethylketal, benzildiethylketal and 2,5-dichlorobenzildimethylketal. Preferably, from about 0.25 to about 1.0% of photoinitiator is present in the polymer-forming composition.
Useful reactive dyes for inclusion in the hydrophilic polymer-forming composition are commonly characterized as "reactive dyes forming ether linkages" in as much as the reactive group or groups in this known class of dyes react with cellulose to form an ether linkage as opposed to, for example, an ester linkage. Such reactive dyes forming ether linkages are generally described in FIBRE-REACTIVE DYES Chapter VI, by W. F. Beech, SAF International Inc., New York (1970), incorporated herein by reference.
This class of reactive dyes are believed to react with hydroxyl, amino, amido or mercapto groups present in the hydrophilic polymer network primarily by nucleophilic addition to form a covalent bond therewith.
A wide variety of commercially available dyes, reactive via nucleophilic substitution, are suitable for use herein. In addition, virtually any desired shade or tint can be achieved through the use of a particular reactive dye or combination of reactive dyes.
Thus, dyes containing an activated double bond which is able to add to a functional group external to the polymer backbone can be used. Exoskeletal bonds activated by a bridge member such as an --SO 2 --, --SO-- or --CO-- group are particularly suitable for use according to the invention. Similarly, dyes with functional groups which can undergo addition reactions with exoskeletal double bonds of the polymer can be employed.
Among the types of reactive dyes suitable for use according to the invention, the following general classes may be mentioned: reactive dyes containing vinyl sulfone precursors, such as β-sulfatoethylsulfonyl, β-sulfatoethylsulfonamido, β-hydroxyethylsulfonyl and β-hydroxyethylsulfonamido substituents, as well as suitable derivatives thereof; dyes containing acryloylamino, β-chloropropionylamino, and β-sulfatopropionylamino and related reactive groups; dyes containing β-sulfato- or β-chloroethylsulfamoyl groups; chloroacetyl dyes; α-bromoacryloyl dyestuffs; and a wide variety of other reactive dyes which have or are being developed for use in the dyeing of natural and synthetic fibers, in particular of cellulose and wool and function by nucleophilic addition.
Also suitable are dyes capable of forming a covalent bond with hydroxyl, amino, amido or mercapto groups present in one or more components of the polymer-forming composition having the general formula ##STR1## wherein D is the radical of an organic dyestuff radical;
R is a divalent organic electron attracting group capable of causing electron withdrawal of the C carbon atoms, thus activating the same;
X is hydrogen or halo; and
Y is a leaving group; or mixtures thereof.
The radical D may advantageously be the radical of an azo, phthalocyanine, azomethine, nitro or anthraquinone dye.
The divalent group --R-- is advantageously bonded directly to an aromatic nuclear carbon of D, or is bonded thereto via an aliphatic group such as an alkylene group, e.g., a lower alkylene group. Most preferably, --R-- is directly bonded to a nuclear carbon atom of D.
Suitable divalent R groups include --CO--, --SO 2 --, --SO--, --NHCO--, --NHSO 2 --, --SO 2 NH-- and the like. Most preferably, --R-- is --SO 2 --, --SO 2 NH--, --CO-- or --NHCO--.
When X is halo, it is most preferably chloro or bromo.
Suitable leaving groups, Y include --Cl, --Br, --OH, di-lower alkylamino, ##STR2## --SO 2 --phenyl, --OSO 3 --Z+ where Z is a cation, --O--SO 3 R 1 or --OSO 2 R 1 where R 1 in each case is alkyl, aryl, aralkyl or alkaryl.
Advantageously where R 1 is alkyl, it is an alkyl of from 1 to 6 carbon atoms, preferably of 1 to 4 carbons, including, for example, methyl, ethyl, isopropyl, butyl and the like. Where R 1 is aryl, it is preferably phenyl or naphthyl. Where R 1 is aralkyl, it is preferably lower alkyl substituted phenyl such as tolyl or xylyl and where R 1 is alkaryl, it is preferably lower alkylenephenyl such as benzyl or phenethyl.
The dichlorotriazine dyes, i.e., those corresponding to the general formula ##STR3## wherein R represents a chromophore radical are preferred for use in the tinting method of this invention. The chromophore radical of the reactive dichlorotriazine dye may be any radical which is not incompatible with the dichlorotriazine nucleus and has an appropriate absorption spectrum. Thus dye radicals of the azo, metallized-azo, anthraquinone, phthalocyanine complex and metal-complexed formazon types are suitable.
Suitable dichlorotriazine reactive dyes include Color Index (CI) Reactive Blue 140, CI Reactive Blue 163, CI Reactive Blue 109, CI Reactive Blue 4, CI Reactive Yellow 86, CI Reactive Yellow 7, Procion Yellow M4RF, Procion Yellow MX-2GA, CI Reactive Orange 4, Procion Orange MX-G, CI Reactive Red 11, CI Reactive Red 1, CI Reactive Red 2, CI Reactive Red 6, and Procion Black MX-CWA. Particularly preferred dichlorotriazine dyes include CI Reactive Blue 163, CI Reactive Red 2, CI Reactive Red 11, CI Reactive Blue 140, CI Reactive Yellow 86 and Procion Black MX-CWA.
The dichlorotriazine dyes are the most reactive of the available reactive dyes as determined by comparative dyeing of cellulose. This allows the use of lower temperatures and lower pH to effect a reaction.
The amount of dye present in the hydrophilic polymer-forming composition can vary considerably with amounts ranging from about 0.010 to about 0.1, and preferably from about 0.03 to about 0.08, weight percent providing generally good results.
Polymerization of the dye-containing hydrophilic polymer-forming composition can be carried out in bulk with the resulting polymer being cut into lens blanks, or "buttons", the buttons then being machined (lathed) to provide contact lenses of the desired optical specifications. For further details, see, e.g., U.S. Pat. No. 3,361,858. Another technique involves molding a contact lens from the hydrophilic polymer-forming composition in a two-piece lens mold as described, e.g., in U.S. Pat. No. 4,121,896. It is preferred, however to prepare contact lenses from the polymer-forming composition employing the spin casting technique. In accordance with this technique, the dye-containing polymer-forming composition is introduced into a mold having a cylindrical wall and an exposed concave bottom surface and the mold is caused to rotate about its vertical axis at a rotational speed and under polymerization conditions sufficient to create a centrifugal force which causes a radially outward displacement of the contents of the mold. By maintaining the rotating mold under predetermined conditions, the outwardly displaced polymerizable material is caused to polymerize to a solid polymeric contact lens. The resulting lens is characterized by a convex optical surface which corresponds to the concave surface of the mold and a concave optical surface whose geometric configuration has been precisely defined, to a significant degree, by the centrifugal force(s) employed during the polymerization cycle.
In one type of spin casting procedure, a plurality of individual molds, each containing a precisely measured quantity of dye-containing polymer-forming composition including a photoinitiator such as any of those previously mentioned, is arranged in a vertically disposed rotatable polymerization tube adapted to receive the molds at its upper end. As the molds which are seated one on top of the other move downwardly through the tube due to their own weight, they pass while spinning through a zone of irradiation, e.g., ultraviolet light, and emerge from the bottom of the tube with the lens in each mold fully formed. Following irradiation, the lenses within their molds can be heated if necessary or desired to complete the polymerization. Suitable apparatus and techniques for practicing this type of spin casting operation are described in U.S. Pat. Nos. 4,468,184; 4,516,924; 4,517,138; 4,517,139; 4,517,140; and, 4,680,149, the contents of which are incorporated by reference herein.
Whichever polymerization procedure is used, the resulting hydrophilic polymer (and any article formed therefrom, e.g., a contact lens) will contain the reactive dye substantially uniformly entrained therein. In order to covalently bond the dye to the polymer backbone, the polymer is contacted with a basic fixing solution, generally heated to a temperature of from about 50° C. and preferably from about 80° C. The basic fixing solution will ordinarily possess a pH of greater than about 8.0 but generally will not exceed about 12.0. Any water-soluble base can be used as the pH adjusting ingredient in the basic aqueous fixing solution, sodium bicarbonate and/or sodium carbonate being preferred. Contact times on the order of from a few seconds to a few minutes are generally sufficient to permanently fix the dye in the polymer through the formation of covalent bonds. Following the fixation step, the tinted hydrophilic polymer can be immersed in an aqueous bath at elevated temperature to remove unreacted dye.
The following examples are illustrative of the hydrophilic polymer tinting method of the present invention.
EXAMPLE 1
This example illustrates the tinting method of the invention carried out upon a hydrophilic contact lens formed by spin casting.
The following monomer mixture was prepared:
______________________________________Component Weight Percent______________________________________HEMA 82.25Solvent 15.5EDGMA 0.5Mold Release 1.5AgentBenzoin Methyl 0.2Ether (Initiator)Reactive Blue No. 4 0.05(Color Index No. 61205)______________________________________
Mixing of the above was conducted within an ice-water bath by agitating for about 1/2 hour with a magnetic stir bar. The resulting homogeneous solution weighing 10 grams was filtered through a 1 micron filter. The monomer mixture was introduced at a predetermined volume within a range of from 18 to 36 microliters into plastic spin casting molds. The molds were then rotated in a spin casting machine at 300 to 400 rpm, the thickness and the power of the resulting lenses being determined by the volume of monomer mixture and the spin casting parameters. Photopolymerization of the monomer occurred as the initiator became activated by the incident UV light generated by a UV lamp associated with the machine. The average exposure time was 20 -60 seconds.
Each lens, still in its mold, was then immersed in an aqueous solution of 2 weight percent sodium bicarbonate and 1 weight percent buffer solute made of di- and tri-sodium phosphates. The solution w-as maintained at a pH of 11 2 to 11.5 and a temperature of 80° C. The moderately basic solution catalyzed a rapid reaction between the entrained reactive dye and the polymer constituting the lens body. Subsequent lens swelling and expansion of the plastic mold caused each permanently tinted lens to separate from its mold.
EXAMPLE 2
This example illustrates the tinting method of the invention carried out upon a hydrophilic contact lens formed by casting in a two-piece lens mold.
The following monomer composition was prepared:
______________________________________Component Weight Percent______________________________________HEMA 97.52EDGMA 1.42,2-azobis(2,4- 1.0dimethylvaleronitrile)(initiator)Reactive Blue No. 4 0.08(Color Index No. 61205)______________________________________
Mixing of the initiator, the dye and the monomers was obtained by agitating the solution with a magnetic stir bar in an ice-water bath for about 1/2 hour. The resulting homogeneous colored solution was filtered through a 1 micron filter. 50 microliters of the reactive dye-containing monomer mixture was introduced into the optical side of each of several plastic molds. The base curve side was mated with the optical side to make up each two-piece mold. Polymerization was then conducted at 110° C. for 1 hour after which the molds halves were separated to provide the lens with its permanently entrained dye.
No color bleaching resulted from the polymerization reaction. The lenses were placed in a 2 weight percent NaHCO 3 solution maintained at 80° C. for 10 minutes and thereafter autoclaved. Each lens was placed in a vial containing saline solution, the solution remaining clear indicating the absence of any leaching of dye from the lenses. Covalent bonding of the dye to the polymer constituting each lens body was considered complete.
EXAMPLE 3
This example illustrates the tinting method of the invention carried out upon a hydrophilic contact lens machined (lathed) to lens specifications from a "button" of hydrophilic polymer.
The following monomer mixture (50 g) was prepared:
______________________________________Component Weight Percent______________________________________HEMA 98.12EDGMA 1.42,2-Azobis(2,4- 0.4dimethyl-4-methoxy-valeronitrile)polymerization(initiator)Reactive Blue No. 4 0.08(Color Index No. 61205)______________________________________
A homogeneously colored solution was obtained by the mixing method described in the previous examples. After filtering through 1 micron filter, the dyed monomer was introduced into a number of small tubes (30×20 mm) to two-thirds their volume. The tubes were sealed with rubber stoppers after being slowly purged with nitrogen for 3 minutes and are maintained at ambient temperature in a water bath, fully immersed, for three days. Solid buttons were formed by slow polymerization at room temperature.
The blue color remained uniform without bleaching. A number of discs were lathe-cut from these buttons and placed in an aqueous solution of 2 weight percent NaHCO 3 and maintained therein at 80° C. for about 10 minutes. The discs were then autoclaved twice. No dye bleaching or color fading was observed. Lathe-cut lenses were made from the discs in a wide range of powers.
EXAMPLE 4
This example illustrates the inoperativeness of tinting a hydrophilic polymer when the step of entraining the reactive dye in the polymer during polymerization of the monomer mixture utilizes a peroxide polymerization initiator.
The following monomer mixture (10 g) was prepared:
______________________________________Component Weight Percent______________________________________HEMA 97.52EDGMA 1.4bis[4-t-butyl cyclo- 1.0hexyl] peroxydicarbonatepolymerization (initiator)Reactive Blue No. 4 0.08(Color Index No. 61205)______________________________________
A homogeneously colored solution was obtained by the mixing method described in the previous examples. After filtering through 1 micron filter, a 50 microliter volume of the dyed monomer was placed within each of several two-piece molds as described in Example 2. Polymerization was conducted at 110° C. for 1 hour. The molds were then separated to obtain the lenses.
The lenses were lightly brown and the polymer clusters which formed at the mold's rim were dark brown. Color bleaching resulted, apparently as a result of the polymerization. The unused portion of the monomer was maintained inside a vial for a week. It was observed that the blue colored monomer polymerized inside the vial to form a cherry-colored mass. The initiator bleached the dye, the reaction possibly having occurred at room temperature. | A hydrophilic polymer, e.g., provided as a contact lens, is tinted by a method which incorporates a reactive dye into the polymer during formation of the latter. Following physical entrainment of the reactive dye in the polymer, the polymer is contacted with an aqueous solution of a base which catalyzes the reaction of the dye with the polymer. In this way, the dye becomes permanently covalently bound to the polymer. | 3 |
BACKGROUND OF INVENTION
Devices for conducting cryotherapy by means of a cold treatment-gas produced from liquid nitrogen are already well-known. In medical practice up to now, exclusively expensive devices have been the rule. These qualify indeed for the requisite high standards of clinics or in the larger practices. For those doctors, however, who make use of cryotherapy in the cases of only a few of their patients, the high investment costs in the introduction of such devices which produce a cold blast has long been a deterrent factor. Thus, in the area of established private practice, there has existed a need for a simplified cold-blast device by which the well-known and traditional expenses entained in the treatment could be reduced dramatically. This applies as well also to individual patients themselves, who carry out cryotherapy on themselves at home. It is a known fact that patients treat themselves after having received due diagnosis and instructions from their doctor regarding cryotherapy. The application of cold packs is likewise no problem for the patient, with careful following of instructions. Since these cold pack refrigerants are usable continuously over a long period, self-treatment in such cases makes sense and is even desirable. The identical pre-conditions for marginal requirements exist and apply also for treating oneself with cold-treatment gas. However, there is no suitable apparatus available for self-treatment.
A therapy device which would be put to use in both of the above areas would have to meet two requirements. First of all, investment costs for it should lie within a range that would be tolerable for a private individual. Secondly, there should not arise any risk for the consumer that would result from the simplification of the device. This is so, namely, because, in the area of the individual's treating himself, the fact must be taken into account that, by and large, he will be a layman in both the technical and the medical sense. The task which lies at the heart of the invention is, therefore, to create a device for the production of a cold-treatment gas from liquid nitrogen for the purposes of cryotherapy that would be conceived for only occasional application and thus would be simple in construction, economical to manufacture, and uncomplicated to use; at the same time, however, entirely without any risk for the consumer.
SUMMARY OF INVENTION
An object of this invention is to provide a device which meets the above needs. In accordance with the invention a heating element is utilized which is built compactly into the liquid nitrogen container. This heating element is constructed as an auto-regulative strip heater and may be installed at the bottom of the container in a spiralling configuration by means of clamps. The supply line may likewise be conducted up and out through the neck of the container by the appropriate clamps situated on the interior walls of the container. Such a heating element may be secured, in the manner mentioned, prior to the final construction of the container, without hindering any of the other work in progress on the container assembly. Prior art devices have used heating elements which must be removed when the container is being filled. One well-known system operates with a heating element that is built permanently in the liquid nitrogen container. However, in such a case there is need for a widenecked container specially made for the occasion. The advantage of the device according to the invention consists therein that it embodies the idea of a standard-type container on the one hand, while on the other, the very small rate of vaporization associated with narrow-necked containers may be resorted to in spite of the compact construction of the heating system.
Essential to the realization of the intended simplicity is the design of the heating element as a self-regulating strip heater.
In order to prevent damaging the heating element or the container after the liquid nitrogen in the container has been consumed, it was always necessary in the case of the previously well-known systems to equip them with expensive temperature or heat-flow regulating devices. The employing of a self-regulating strip heater renders these devices superfluous. These heating cables are obtainable as ordinary merchandise. The fact is of significance for the device according to the invention that, without external influence of the supply of current, the heating power drops, and the temperature will not exceed a certain limit. By a correct dimensioning of the self-regulating strip heater, the maximal temperature limit can be so determined that, when the nitrogen has been depleted, neither the container nor the heating element will be damaged. The self-regulating strip heater is provided with an insulation layer made of plastic, which exhibits high rupture resistance at very low temperatures. Thus, this insulating layer is not impaired mechanically in its intended role in the liquid nitrogen container. In addition, the plastic layer forms a protection against moisture entering the feed line. Thus, the humidity that is to be expected always in conjunction with lower temperatures will not cause any difficulties for the electrical safety of the system.
Taking into account the precise and purposeful use to which it will be put, the volume of the container will be limited to a maximum of 50 liters. The device according to the invention may therefore be constructed with a view to conservation of space. On the other hand, it may be made use of for several weeks with just one filling.
As a container for liquid nitrogen, a standard vessel with a small flange may be used which is, as a rule, equipped with safety valve and manometer. For its being put into service in accordance with the invention, it needs to be pressurized during construction, because of heat introduction, only to the extent that the resultant cold gas must be discharged from the open end of the vessel. Thus, there is no need for a manometer. Instead of it, the feed line of the heating cable will exit through the provisional lateral opening on the neck. As feed or supply able, ordinary electric cables may be employed, the insulatory layers of which will consist of cold-resistant plastic. These supply lines are likewise so mounted that they cannot be shifted. Thus, any mechanical demand placed on them in their cold state will not take place. The safety valve is to be retained on the container, in order for the system to be protected against any undesired pressure buildup resulting from a negligent or unintentional closing of the exhaust orifice.
In the system just described, the actual neck opening in the area of the flange is completely separate from the heating apparatus. The installment of the treatment hose is therefore made essentially more simple, in comparison with the usual well-known devices, because, whenever a dismantling is necessary in order to fill the container, it is only the treatment hose, not the heating element, that needs to be removed.
The cooling of the external hose surfaces must be avoided, not for its length of service, but only for a single treatment, which as a rule does not last for more than 2 to 3 minutes. Therefore, there is no necessity for lining the hose with expensive insulation. It has proven to be sufficient to insulate the actual refrigerant-conductive spiral hose of PVC simply with a layer of plastic foil and one of foil-layered felt. This is then covered completely with a plastic corrugated hose.
In the device according to the invention, any regulation of temperature of the refrigerant gas is waived. Because of heating with constant current, a constant stream of cold gas will result during the operation which, after a brief time of flow, produces a constant refrigerant gas temperature at the nozzle of the hose.
Given all the conditions which have been mentioned, it is also true that the electrical guidance of the apparatus is considerably simplified, in comparison with previously known systems. The strip heater may be connected to the system voltage directly. In order to meet the requisite safety criteria, it is necessary only to hook up a main switch and a safety element into this circuit.
In addition, this circuit may be provided with a time-control unit which will allow advance choice of treatment durations for every use. When the clock runs out, the apparatus will automatically shut itself off. This time-control unit is of course not absolutely necessary for operating the therapy device; however, it increases the convenience index without obstructing in any way the object of the invention, namely, to present a commendable device.
The various electrical installation elements described may be secured within a small casing located on the neck of the container, but without interfering with the dismantling of the treatment hose, or the filling of the container through the neck orifice.
THE DRAWINGS
FIG. 1 is a cut-away side view of the container with heating element in accordance with this invention; and
FIG. 2 is an exploded view of the neck of the container shown in FIG. 1.
DETAILED DESCRIPTION
The container 1 represented in FIG. 1 is a standard vessel, designed with a narrow neck, with 30 l contents space. The details of insulation and the double-walled design are not presented. Corresponding to the invention, there is a self-regulating strip heater 2 at the bottom and on the internal wall of the container, solidly installed with the expedient of clamps 3, and drawn up to the outside by way of the neck 4 of the container.
FIG. 2 shows the neck of the container in detail. A small casing 5 is secured to it, in which the main switch, or control switch 6, fuses 7, and a time-control unit or clock, 8, are arranged. As soon as the plug 9 is connected to the electrical circuit, the device is ready for operation. After activation of the time-control unit 8, cold treatment-gas is produced for the duration corresponding to the time selected, which is conducted to the place of treatment by the hose 10. The hose 10 is fastened to the neck 4 of the container by means of the flange 11. Inside the flange 11, a safety valve 12 is arranged.
From the viewpoint of safety technology, the device of the invention satisfies the requirements which apply to cold-blast therapy. Even with continual use of the device, only very limited amounts of nitrogen are liberated, so that, under normal conditions, the oxygen content of the surrounding air in the room will not be reduced appreciably. The cold treatment-gas that is produced is dry. The escape of liquid nitrogen from the treatment hose is not possible. The employing of the device in the area of self-treatment is therefore entirely supportable.
The device of the invention may be produced with a fraction of the expense that is necessary for the currently known devices for conducting cryotherapy. The investment costs associated with it are obviously, for the patient, situated within a quantitative range which permits him to acquire the device without any assistance whatsoever from health insurance.
The costs of operation of the device may be estimated on the basis of statistical mean value for treatment sessions. On the assumption of an average duration of treatment of 2 minutes, and one of 2 treatments per day, the conclusion is that the liquid nitrogen use in this treatment and the auto-vaporization of 30 l of the container enjoy a duration period of the entire system of more than 3 weeks. The result is a practical re-servicing interval on the part of the refrigerant suppliers.
SUMMARY
Devices for producing a cold treatment-gas from liquid nitrogen for cryotherapy are well-known, and have been confirmed through their services in clinics and medical centers. Often, there is a cold mixture of nitrogen and atmospheric air produced as treatment gas. Because of installations for regulating mixture and temperature, humidity elimination and purity of the ambient air, these well-known devices are expensive and occupy comparatively large space.
A commendable small device for only occasional applications, as, for instance, use in the home, consists of a standard small container with a maximum volume content of 50 l, in the inside of which an electrical heating element comprised of a self-regulating strip heater 2 is mounted. Inside a casing 5 which is mounted on the neck 4 of the container 1, an electrical fuse 7, the control switch 6, and a time-control unit 8 may be arranged. See FIG. 2. | A device for producing cyrotherapy with liquid nitrogen includes a container for the liquid nitrogen with electrical heating in its interior. The container has a maximum volume of 50 l and the electrical heating is a heating element comprising a self-regulating strip heater secured in the interior of the container. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of Provisional Application Serial No. 60/186,406, filed Mar. 2, 2000.
BACKGROUND OF THE INVENTION
This invention relates to a durable and imaged flame-retardant nonwoven fabric that can be used for flame-retardant apparel and other related applications. There are numerous flame-retardant fibers commercially available. E. I du Pont de Nemours and Company provides flame-retardant aramid fibers sold under the trade names of NOMEX® and KEVLAR®. NOMEX® materials were developed for applications requiring dimensional stability and excellent heat resistance, and which do not flow or melt upon heating. Decomposition and charring does not proceed at a significant rate until well over 350° C. without melting. NOMEX® materials in fibrous form have been used in protective apparel and similar applications, and can be processed by conventional textile technology. Heretofore, comparable flame-retardant nonwoven fabrics have been expensive to manufacture, and have not been susceptible of imaging by high pressure water jet entangling. Specific examples of prior art materials are set forth below.
U.S. Pat. No. 4,199,642 discloses a flame resistant fiberfill batt consisting of polyester fiberfill and synthetic organic filamentary materials, including poly(m-phenylene isophthalamide) blended therewith that maintains its physical integrity when exposed to the flame from a burning match.
U.S. Pat. No. 4,463,465 discloses an aircraft seat cushion including a highly heat-sensitive urethane foam covered by a flexible matrix, which may comprise a NOMEX® fabric. A further gas barrier layer may also be provided, which can also be a NOMEX® fabric.
A wet-type survival suit is disclosed in U.S. Pat. No. 4,547,904, including inner and outer NOMEX® layers, which provide maximum protection against fire.
A fire-retardant panel is disclosed in U.S. Pat. No. 4,726,987 and No. 4,780,359 which includes one or more layers of NOMEX® fiber that may be combined with adjacent fibrous layers by needle punching.
U.S. Pat. No. 4,748,065 discloses a flame resistant fabric, wherein a spunlaced fabric formed of fibers, such as NOMEX®, is brush-coated with an aqueous slurry containing activated carbon particles. The resulting fabric was subsequently dried and softened by crepeing. Laminates, including spunlaced outer layers of NOMEX® fibers, are also disclosed.
A fire-blocking textile fabric is disclosed in U.S. Pat. No. 4,750,443, which includes three to seven nonwoven layers that are hydraulically needled to one another. Each layer may be formed of NOMEX® fibers; however, an outer woven layer may be provided to impart dimensional stability and abrasion resistance.
U.S. Pat. No. 4,937,136 discloses a laminate for use in fire protective garments. The laminate includes a nonwoven fabric comprised of a blend of wool and synthetic fibers capable of high temperature performance, such as NOMEX®. The laminate includes an outer shell, which may also be formed of NOMEX® and an intermediate moisture barrier layer.
An animal bed cover is disclosed in U.S. Pat. No. 5,226,384, which is formed of an aramid fabric sheet, e.g. KEVLAR® with a polyester fabric sheet laminated to it.
In U.S. Pat. No. 5,252,386, a fire retardant entangled polyester nonwoven fabric is disclosed. The patent states that the fabric has balanced tensile strength properties in the cross- and machine-directions and improved fire retardant properties by cross-stretching the entangled fabric, after the fabric has been wetted with an aqueous-based fire retardant composition, and drying the wetted fabric while maintaining it in its stretched state.
U.S. Pat. No. 5,279,879 discloses a flame-retarding nonwoven fabric formed of partially graphitized polyacrylonitrile fibers that are bonded by water jet needling. The fabric may be reinforced by warp-wise and weft-wise threads, and the fabric may be combined with a decorative fabric/material by adhesive securement.
U.S. Pat. No. 5,475,903 discloses a fabric that is formed by carding synthetic fibers, such as polyester fibers, cross-lapping the carded web to orient the fibers in the cross-direction, drafting the cross-lapped web to reorient certain of the fibers in the machine-direction, applying unbonded wood fibers to the top of the drafted web, and hydroentangling the resulting web to entangle the wood fibers with those of the polyester drafted web. A liquid fire-retardant composition is then applied to the hydroentangled web.
In U.S. Pat. No. 5,578,368, a fire-resistant material is disclosed, which includes a fiberfill batt, that may comprise polyester fibers, and a fire-resistant aramid fibrous layer like NOMEX®, at one, or both, faces of the batt. The aramid fiber layer may be joined to the fiberfill batt by hydroentangling.
U.S. Pat. No. 5,609,950 and No. 5,766,746 disclose a flame-retardant nonwoven fabric wherein fleece, including cellulose fibers having a flame-retardant containing phosphorus, is bonded by water jet entanglement.
In order to provide adequate protection to the skin from burn damage by heat and/or flame, currently available fabrics for flame retardant clothing rely upon high basis weights and bulks. A practical consequence of extended wear of articles made of these heavy fabrics is fatigue and potential dehydration due to poor air circulation. Blends of melamine fibers (BASF Corporation under the trade name of BASOFIL) with varying ratios of aramid fibers, as is disclosed in U.S. Pat. No. 5,560,990, hereby incorporated by reference, are known. It has been discovered that when a melamine/aramid fiber blend is hydroentangled and a 3-dimensional image imparted, thermal protection to the skin at lower basis weights are maximized, thereby providing significantly improved wearer comfort and safety.
SUMMARY OF THE INVENTION
The fabric of the present invention is a hydroentangled, imaged nonwoven fabric formed from a blend of melamine and aramid fibers. While the heat and flame-resistant properties of aramid fibers are well understood and appreciated, fabrics produced using these aramid fibers are known to be heavy in weight and low in air permeability. When converted into flame retardant apparel, fatigue due to heat and dehydration in instances of extended wear, are commonplace.
It has been discovered that the use of melamine fibers, when blended with aramid fibers in relative ratios of between 45 weight percent and 55 weight percent, and preferably about 50 weight percent, of the melamine fiber, provides improvement in Thermal Protective Properties (TPP). In a preferred embodiment, a carded staple fiber blend is hydroentangled by the use of high-pressure water jets followed by imaging on a three-dimensional surface to provide a fabric with a basis weight range of between 65 grams per square meter and 150 grams per square meter, a resultant air permeability greater than 65 CFM per gram fabric weight per cubic centimeter and a TPP rating greater than 11.4 cal-sec per square centimeter.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic representation of a production line upon which the process of the present invention is practiced and the fabric of the present invention is produced; and
FIGS. 2 a through 4 b are schematic representations of preferred three-dimensional imaging surfaces;
DESCRIPTION OF PREFERRED EMBODIMENTS
While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment of the invention, with the understanding that the present disclosure is to be considered as an exemplification of the invention, and is not intended to limit the invention to the specific embodiment illustrated.
With reference to FIG. 1, therein is illustrated an apparatus for practicing the present method for forming a nonwoven fabric. The fabric is formed from a fibrous matrix which comprises a blend of melamine and aramid staple length. The fibrous matrix is preferably carded and subsequently air-randomized to form a precursor web, designated P.
FIG. 1 illustrates a hydroentangling apparatus for forming nonwoven fabrics in accordance with the present invention. The apparatus includes a foraminous forming surface in the form of belt 12 upon which the precursor web P is positioned for pre-entangling. Precursor web P is then sequentially passed under entangling manifolds 14 , whereby the precursor web P is subjected to high pressure water jets 16 . This process is one well-known to those skilled in the art and is generally as taught by Evans in U.S. Pat. No. 3,485,706, incorporated herein by reference.
The entangling apparatus of FIG. 1 further includes an imaging and patterning drum 18 comprising a three-dimensional image transfer device for effecting imaging and patterning of the now-entangled precursor web. After pre-entangling, the precursor web is then trained over a guide roller 20 and directed to an image transfer device 18 , where a three-dimensional image is imparted into the fabric. The web of blended fibers is juxtaposed to image transfer device 18 , and high pressure water from manifolds 22 is directed against the outwardly facing surface from jets spaced radially outwardly of image transfer device 19 . Image transfer device 18 and manifolds 22 may be formed, and operated, in accordance with the teachings of commonly assigned U.S. Pat. Nos. 5,098,764, 5,244,711, 5,822,823, and 5,827,597, the disclosures of which are expressly incorporated herein by this reference. It is presently preferred that the precursor web P be given a three-dimensional image suitable to provide the desired air permeability of the final imaged fabric. The entangled fabric can then be vacuum dewatered at 24 , and dried on drying cans 26 .
EXAMPLES 1-6
EXAMPLE 1
Using a forming apparatus as illustrated in FIG. 1, a nonwoven fabric was made in accordance with the present invention by providing a precursor web comprising a blend of 50 weight percent melamine fibers and 50 weight percent aramid fibers. The web had a basis weight of approximately 85 grams per square meter.
The fabric comprised BASF BASOFIL (assorted denier and staple length of between 0.5 and 4.0 inches) and Du Pont NOMEX® (1.5 denier and 2 inch staple length). Prior to patterning and imaging of the precursor web, the web was pre-entangled by a series of entangling manifolds such as diagrammatically illustrated in FIG. 1 . FIG. 1 illustrates disposition of precursor web P on a foraminous forming surface in the form of belt 10 , with the web acted upon by sequential entangling manifolds 14 . In the present examples, each of the entangling manifolds included 127-micron orifices spaced at 40 per inch, with four of the manifolds successively operated at 100, 300, 600, and 800 pounds per square inch. The entangling apparatus of FIG. 1 further includes an imaging and patterning drum 18 comprising a three-dimensional image transfer device for effecting imaging and patterning of the now-entangled precursor web. The entangling apparatus includes three entangling manifolds 22 which act in cooperation with the three-dimensional image transfer device of drum 18 to effect patterning of the fabric. In the present example, the entangling manifolds 22 were each operated at 2500 pounds per square inch, 127-micron orifices spaced at 40 per inch, and at a line speed of 30 feet per minute.
The three-dimensional image transfer device of drum 18 was configured as a so-called “herringbone”, as illustrated in FIGS. 2 a and 2 b.
A resultant fabric had a basis weight of 91.1 grams per square meter, a bulk of 0.031 inches, and a machine-direction strip tensile strength of 62.3 grams per centimeter as measured on an INSTRON Testing Device. Air permeability was 281.1 CFM as measured by ASTM D737. The TPP (thermal protection property) for this material, as measured by the test protocol specified in the NFPA 1971, 1997 Ed. (section 6,10), was 11.8.
For this material, a value of air permeability to mass/volume of 79.6 CFM/gram/cc was obtained.
EXAMPLE 2
A fabric as made in the manner described in EXAMPLE 1, whereby in the alternative the three-dimensional image transfer device of drum 18 was configured as a so-called 33×28, a rectilinear pyramidal forming pattern having 33 lines per inch by 28 lines per inch configured in accordance with FIG. 13 of U.S. Pat. No. 5,098,764, except mid-pyramid drain holes are omitted. Pyramid height is approximately 1.5 mm, with the long axis of each pyramid being oriented in the machine direction.
A resultant fabric had a basis weight of 89.1 grams per square meter, a bulk of 0.030 inches, a machine-direction strip tensile strength of 57.9 grams per centimeter, an air permeability of 283.9 CFM and a TPP of 11.5.
For this material, a value of air permeability to mass/volume of 80.9 CFM/gram/cc was obtained.
EXAMPLE 3
A fabric as made in the manner described in EXAMPLE 1, whereby in the alternative the three-dimensional image transfer device of drum 18 was configured as a so-called 20×20, a rectilinear pyramidal forming pattern having 20 lines per inch by 20 lines per inch configured in accordance with FIG. 13 of U.S. Pat. No. 5,098,764, except mid-pyramid drain holes are omitted. Pyramid height is 0.025 inches, with the drain holes at the corners of each pyramid having a 0.02 inch diameter. Drainage area is 12.5% of the surface area.
A resultant fabric had a basis weight of 91.9 grams per square meter, a bulk of 0.030 inches, a machine-direction strip tensile strength of 62.0 grams per centimeter, an air permeability of 246.8 CFM and a TPP of 11.8.
For this material, a value of air permeability to mass/volume of 68.2 CFM/gram/cc was obtained.
EXAMPLE 4
A fabric as made in the manner described in EXAMPLE 1, whereby in the alternative the three-dimensional image transfer device of drum 18 was configured as a so-called “pique”, as illustrated in FIGS. 3 a and 3 b.
A resultant fabric had a basis weight of 87.2 grams per square meter, a bulk of 0.030 inches, a machine-direction strip tensile strength of 60.0 grams per centimeter, an air permeability of 241.5 CFM and a TPP of 11.9.
For this material, a value of air permeability to mass/volume of 70.3 CFM/gram/cc was obtained.
EXAMPLE 5
A fabric as made in the manner described in EXAMPLE 1, whereby in the alternative the three-dimensional image transfer device of drum 18 was configured as a so-called “diamond”, as illustrated in FIGS. 4 a and 4 b.
A resultant fabric had a basis weight of 88.5 grams per square meter, a bulk of 0.025 inches, a machine-direction strip tensile strength of 54.5 grams per centimeter, an air permeability of 241.5 CFM and a TPP of 11.5.
For this material, a value of air permeability to mass/volume of 69.3 CFM/gram/cc was obtained.
COMPARATIVE EXAMPLE 6
A commercially available fabric was obtained in the form of Du Pont E89, type P-27.
Testing of this fabric under identical conditions as above gave results of a basis weight of 101.6 grams per square meter, a bulk of 0.028 inches, a machine-direction strip tensile strength of 61.2 grams per centimeter, an air permeability of 181.0 CFM and a TPP of 11.0.
For this material, a value of air permeability to mass/volume of 45.2 CFM/gram/cc was obtained.
Table 1 sets forth test data for the above-described fabrics.
TABLE 1
Modi-
DuPont E
fied
Plain
Rip-
Dia-
89/P-27
Twill
Weave
stop
Pique
mond
Mass per Unit
101.6
91.1
89.1
91.9
87.2
88.5
Area (gsm)
Mass per Unit
4.0
3.6
3.5
3.6
3.4
3.5
Volume (cc)
Bulk (mils)
28.3
31
30
30
30
25
Tensile Strength -
61.2
62.3
57.9
62
60
54.5
MD
Tensile Strength -
62.3
26.1
26.8
28.2
26.8
28.9
CD
TPP - Single Layer
11.0
11.8
11.5
11.8
11.9
11.5
(SD<
Flame Resistance -
4.0
2.0
2.0
2.0
2.0
2.0
Vertical test
Afterglow MD (sec)
Flame resistance -
3.5
2.0
1.0
2.0
1.5
1.0
Vertical test
Afterglow CD (sec)
Normalized Air
45.2
79.6
80.9
68.2
70.3
69.3
Permeability
(CFM/gram/cc) | The present invention is directed to a durable and imaged flame-retardant nonwoven fabric that can be used for flame-retardant apparel and other related applications. The fabric is formed by providing a precursor web consisting of a blend of melamine fibers and aramid fibers. The precursor web is hydroentangled on a three-dimensional image transfer device for formation of the fabric. The resultant fabric provides desirable air permeability and Thermal Protective Properties. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method of making a relay.
2. Description of the Related Art
As shown in FIG. 1 , a conventional method of making a relay 10 (see FIG. 9 ) comprises steps 21 to 26 .
As shown in FIGS. 1 and 2 , the step 21 is to prepare a relay core member 11 including a base plate 111 that extends in a horizontal direction (X) and that is formed with a through hole 116 , a top plate 112 that extends in the horizontal direction (X) and that is spaced apart from the base plate 111 in a vertical direction (Y), a coil unit 110 that extends in the vertical direction (Y) and that is disposed between the base and top plates 111 , 112 , and a connecting plate 114 that interconnects the base and top plates 111 , 112 and that is disposed between the coil unit 110 and the through hole 116 . The coil unit 110 includes a core 113 , a coil 12 wound on the core 113 , and a pair of rods 115 , each of which is coupled to the coil 12 and extends through the base plate 111 .
As shown in FIGS. 1 , 3 , and 4 , the step 22 is to prepare a first terminal 13 that has a first terminal portion 131 formed with a plate engaging notch 1310 , a first fixed portion 132 extending perpendicularly from one edge of the first terminal portion 131 , and a first contact 133 disposed on the first fixed portion 131 , and to couple the first terminal 13 to the relay core member 11 by moving the first terminal 13 horizontally relative to the relay core member 11 such that the plate engaging notch 1310 engages the base plate 111 of the relay core member 11 , that a portion of the first terminal portion 131 extends downwardly relative to the base plate 111 , and that the first fixed portion 132 extends horizontally above the top plate 112 of the relay core member 11 .
As shown in FIGS. 1 , 5 , and 6 , the step 23 is to prepare a second terminal 14 that has a second terminal portion 141 , a resilient portion 142 extending perpendicularly from one edge of the second terminal portion 141 , a second contact 143 disposed on the resilient portion 142 , a pair of opposite wing portions 144 formed at two sides of the second terminal portion 141 , and a pair of tongue pieces 145 formed respectively at the wing portions 144 , and to couple the second terminal 14 to the relay core member 11 by moving the second terminal 14 vertically relative to the relay core member 11 such that the second terminal portion 141 extends downwardly through the through hole 116 in the base plate 111 , that the resilient portion 142 extends horizontally above the top plate 112 and the first fixed portion 132 of the first terminal 13 , and that the second contact 143 is registered with the first contact 133 of the first terminal 13 . After the second terminal 14 is coupled to the relay core member 11 , an operator has to fold each of the wing portions 144 manually toward the connecting plate 114 with the use of a tool (not shown) such that the tongue pieces 145 engage respectively opposite sides of the connecting plate 144 , thereby positioning the second terminal 14 relative to the relay core member 11 .
As shown in FIGS. 1 , 7 , and 8 , the step 24 is to prepare a third terminal 15 that has a third terminal portion 151 formed with plate engaging notches 1510 , 1511 , a second fixed portion 152 extending perpendicularly from one edge of the third terminal portion 151 , and a third contact 153 disposed on the second fixed portion 152 , and to couple the third terminal 15 to the relay core member 11 by moving the third terminal 15 horizontally relative to the relay core member 11 such that the plate engaging notches 1510 , 1511 respectively engage the top and base plates 112 , 111 of the relay core member 11 , that a portion of the third terminal portion 151 extends downwardly relative to the base plate 111 , that the second fixed portion 152 extends horizontally above the resilient portion 142 of the second terminal 14 , and that the third contact 153 is registered with the second contact 142 .
The step 25 is to test the resiliency of the resilient portion 142 of the second terminal 14 via a testing instrument (not shown). If the testing result does not fall within the standard range, the operator has to adjust manually the resilient portion 142 with the use of a tool so as to meet the standard requirement.
As shown in FIGS. 1 and 9 , the step 26 is to enclose the relay core member 11 , the first terminal 13 , the second terminal 14 , and the third terminal 15 within a housing 16 , and to seal the housing 16 with resin 17 filled between the housing 16 and the base plate 111 of the relay core member 11 .
In use, the second contact 143 of the second terminal 14 contacts the third contact 153 of the third terminal 15 to form a first circuit when current does not flow through the coil unit 110 . When current flows through the coil unit 110 , an electromagnetic field is generated to attract the resilient portion 142 of the second terminal 14 such that the second contact 143 is separated from the third contact 153 and contacts the first contact 133 of the first terminal 13 , thereby forming a second circuit.
However, since the second terminal 14 is vertically coupled to the relay core member 11 , and since the tongue pieces 145 will affect vertical movement of the second terminal 14 if the wing portions 144 are folded prior to coupling the second terminal 14 to the relay core member 11 , the second terminal 14 has to be assembled manually. Moreover, since the resiliency of the resilient portion 142 of the second terminal 14 may deviate from the standard range during manual assembly of the second terminal 14 , the step 25 of testing the resiliency of the resilient portion 142 of the second terminal 14 after coupling to the relay core member 11 is required. Therefore, the conventional assembling method results in a relatively high cost of manufacture. Furthermore, if the tolerance range of the through hole 116 in the base plate 111 of the relay core member 11 is too large, the second terminal portion 141 of the second terminal 14 may not be properly assembled relative to the relay core member 11 since the second terminal portion 141 extends loosely through the through hole 116 , such that the operator has to spend more time to assemble properly the second terminal 14 , thereby resulting in higher manufacturing costs.
SUMMARY OF THE INVENTION
Therefore, the object of the present invention is to provide a method of making a relay with a higher efficiency and a lower cost of manufacturing.
Accordingly, a method of making a relay of the present invention comprises the steps of: (A) preparing a relay core member that includes a base plate extending in a horizontal direction and formed with first, second, and third notches, a top plate extending in the horizontal direction and spaced apart from the base plate in a vertical direction, a coil unit extending in the vertical direction and disposed between the base and the top plates, and a connecting plate interconnecting the base and top plates and disposed between the second notch in the base plate and the coil unit; (B) preparing a first terminal that has a first terminal portion, a first fixed portion extending perpendicularly from one edge of the first terminal portion, and a first contact disposed on the first fixed portion, and coupling the first terminal to the relay core member by moving the first terminal horizontally relative to the relay core member such that the first terminal portion enters the first notch in the horizontal direction and extends downwardly through the base plate, and that the first fixed portion extends horizontally above the top plate of the relay core member; (C) preparing a second terminal that has a second terminal portion, a resilient portion extending perpendicularly from one edge of the second terminal portion, a second contact disposed on the resilient portion, a pair of opposite wing portions formed at two sides of the second terminal portion, and a pair of tongue pieces formed respectively at the wing portions, and coupling the second terminal to the relay core member by moving the second terminal horizontally relative to the relay core member such that the second terminal portion enters the second notch in the horizontal direction and extends downwardly through the base plate, that the resilient portion extends horizontally above the first fixed portion of the first terminal, that the second contact is registered with the first contact, and that the tongue pieces engage the connecting plate; (D) preparing a third terminal that has a third terminal portion, a second fixed portion extending perpendicularly from one edge of the third terminal portion, and a third contact disposed on the second fixed portion, and coupling the third terminal to the relay core member by moving the third terminal horizontally relative to the relay core member such that the third terminal portion enters the third notch in the horizontal direction and extends downwardly through the base plate, that the second fixed portion extends horizontally above the resilient portion of the second terminal and is supported thereat by the top plate of the relay core member, and that the third contact is registered with the second contact; and (E) enclosing the relay core member, the first terminal, the second terminal, and the third terminal within a housing, and sealing the housing with resin filled between the housing and the base plate of the relay core member.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which:
FIG. 1 is a flow chart of a conventional method of making a relay;
FIG. 2 is a perspective view of a relay core member used in the conventional method;
FIG. 3 is a fragmentary exploded perspective view, illustrating a first terminal before being coupled to the relay core member according to the conventional method;
FIG. 4 is a fragmentary assembled perspective view, illustrating the first terminal after being coupled to the relay core member according to the conventional method;
FIG. 5 is a fragmentary exploded perspective view, illustrating a second terminal before being coupled to the relay core member according to the conventional method;
FIG. 6 is a fragmentary assembled perspective view, illustrating the second terminal after being coupled to the relay core member according to the conventional method;
FIG. 7 is a fragmentary exploded perspective view, illustrating a third terminal before being coupled to the relay core member according to the conventional method;
FIG. 8 is a fragmentary assembled perspective view, illustrating the third terminal after being coupled to the relay core member according to the conventional method;
FIG. 9 is an assembled perspective view, illustrating the relay core member enclosed in a housing with sealant filled therebetween according to the conventional method;
FIG. 10 is a flow chart of a preferred embodiment of a method of making a relay according to the invention;
FIG. 11 is a perspective view of a relay core member used in the preferred embodiment;
FIG. 12 is a fragmentary exploded perspective view, illustrating a first terminal before being coupled to the relay core member according to the preferred embodiment;
FIG. 13 is a fragmentary assembled perspective view, illustrating the first terminal after being coupled to the relay core member according to the preferred embodiment;
FIG. 14 is a fragmentary exploded perspective view, illustrating a second terminal before being coupled to the relay core member according to the preferred embodiment;
FIG. 15 is a fragmentary assembled perspective view, illustrating the second terminal after being coupled to the relay core member according to the preferred embodiment;
FIG. 16 is a fragmentary exploded perspective view, illustrating a third terminal before being coupled to the relay core member according to the preferred embodiment;
FIG. 17 is a fragmentary assembled perspective view, illustrating the third terminal after being coupled to the relay core member according to the preferred embodiment;
FIG. 18 is an assembled perspective view, illustrating the relay core member enclosed in a housing with sealant filled therebetween according to the preferred embodiment;
FIG. 19 is an assembled sectional view of the relay made according to the preferred embodiment when forming a first circuit; and
FIG. 20 is a view similar to FIG. 19 , but illustrating the relay when forming a second circuit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Before the present invention is described in greater detail, it should be noted that the relative positional terminology used in the following description, e.g., “horizontal direction (X)” and “vertical direction (Y)”, are based on the directions illustrated in the accompanying drawings, and that the horizontal direction (X) is perpendicular to the vertical direction (Y).
As shown in FIG. 10 , the preferred embodiment of a method of making a relay according to the present invention comprises steps 31 to 35 .
As shown in FIGS. 10 to 12 , the step 31 is to prepare a relay core member 40 including a base plate 41 that extends in a horizontal direction (X), a top plate 42 that extends in the horizontal direction (X) and that is spaced apart from the base plate 41 in a vertical direction (Y), a coil unit 49 that extends in the vertical direction (Y) and that is disposed between the base and top plates 41 , 42 , and a connecting plate 44 that interconnects the base and top plates 41 , 42 . The coil unit 49 includes a core 43 , a coil 46 wound on the core 43 , and a pair of rods 45 , each of which is coupled to the coil 46 and extends through the base plate 41 .
The base plate 41 of the relay core member 40 has one edge formed with a first notch 411 and a third notch 413 that extend in the horizontal direction (X) and that are spaced apart from each other, and has an opposite edge formed with a second notch 412 that extends in the horizontal direction (X). The connecting plate 44 is disposed between the second notch 412 and the coil unit 49 . Preferably, the second notch 412 has a flaring opening 414 . The top plate 42 is formed with a pair of spaced apart first and second engaging blocks 421 , 422 at one edge above the first and third notches 411 , 413 .
As shown in FIGS. 10 , 12 , and 13 , the step 32 is to prepare a first terminal 60 that has a first terminal portion 61 , a first fixed portion 62 extending perpendicularly from one edge of the first terminal portion 61 , and a first contact 63 disposed on the first fixed portion 61 , and to couple the first terminal 60 to the relay core member 40 by moving the first terminal 60 horizontally relative to the relay core member 40 such that the first terminal portion 61 enters the first notch 411 in the horizontal direction (X) and extends downwardly through the base plate 41 , and that the first fixed portion 62 engages the first engaging block 421 on the top plate 42 and extends horizontally above the top plate 42 of the relay core member 40 .
As shown in FIGS. 10 , 14 , and 15 , the step 33 is to prepare a second terminal 70 that has a second terminal portion 71 , a resilient portion 72 extending perpendicularly from one edge of the second terminal portion 71 , a second contact 73 disposed on a distal end part 721 of the resilient portion 72 , a pair of opposite wing portions 74 formed at two sides of the second terminal portion 71 , and a pair of tongue pieces 75 formed respectively at the wing portions 74 , and to couple the second terminal 70 to the relay core member 41 by moving the second terminal 70 horizontally relative to the relay core member 41 such that the second terminal portion 71 enters the second notch 412 in the horizontal direction (X) and extends downwardly through the base plate 41 , that the resilient portion 72 extends horizontally above the top plate 42 and the first fixed portion 62 of the first terminal 60 , and that the second contact 73 is registered with the first contact 63 of the first terminal 60 . Preferably, the wing portions 74 are folded respectively at an angle relative to the second terminal 70 prior to coupling the second terminal portion 71 to the relay core member 40 , such that the tongue pieces 75 of the second terminal 70 engage simultaneously opposite sides of the connecting plate 44 of the relay core member 40 when the second terminal portion 71 is inserted in the second notch 412 .
As shown in FIGS. 10 , 16 , and 17 , the step 34 is to prepare a third terminal 80 that has a third terminal portion 81 , a second fixed portion 82 extending perpendicularly from one edge of the third terminal portion 81 , and a third contact 83 disposed on the second fixed portion 82 , and to couple the third terminal 80 to the relay core member 40 by moving the third terminal 80 horizontally relative to the relay core member 40 such that the third terminal portion 81 enters the third notch 413 in the horizontal direction (X), and extends downwardly through the base plate 41 , that the second fixed portion 82 extends horizontally above the resilient portion 72 of the second terminal 70 and is supported thereat by the second engaging block 422 on the top plate 42 of the relay core member 40 , and that the third contact 83 is registered with the second contact 73 .
As shown in FIGS. 10 , 18 , and 19 , the step 35 is to enclose the relay core member 40 , the first terminal 60 , the second terminal 70 , and the third terminal 80 within a housing 90 , and to seal the housing 90 with resin 100 filled between the housing 90 and the base plate 41 of the relay core member 40 . Preferably, the housing 90 includes a block 91 extending into the second notch 412 in the base plate 41 so as to prevent the resin 100 from flowing into the relay core member 40 .
In use, the second contact 73 of the second terminal 70 contacts the third contact 83 of the third terminal 80 to form a first circuit (see FIG. 19 ) when current does not flow through the coil unit 49 . When current flows through the coil unit 49 , an electromagnetic field is generated to attract the resilient portion 72 of the second terminal 70 such that the second contact 73 is separated from the third contact 83 and contacts the first contact 63 of the first terminal 60 , thereby forming a second circuit (see FIG. 20 ).
Since the second terminal 70 is coupled horizontally to the relay core member 40 with the second terminal portion 71 entering the second notch 412 in the base plate 41 via the opening 414 , and since the tongue pieces 75 of the second terminal 70 engage simultaneously the connecting plate 44 when the second terminal portion 71 is inserted in the second notch 412 , the step of coupling the second terminal 70 to the relay core member 40 can be automated as well as those of the first and third terminals 60 , 80 . Moreover, the aforementioned assembling process does not result in deviation of the resiliency of the resilient portion 72 of the second terminal 70 . Compared to the prior art, the manual assembling and the manual adjustment of the second terminal can be eliminated in this invention, thereby resulting in a higher efficiency and a lower cost of manufacturing.
While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements. | A method of making a relay includes: preparing a relay core member; coupling first, second and third terminals to the relay core member by moving the same horizontally relative to the relay core member such that terminal portions of the first, second and third terminals enter notches formed in the relay core member in a horizontal direction; and enclosing the relay core member, the first terminal, the second terminal, and the third terminal within a housing, and sealing the housing with resin. | 8 |
CROSS REFERENCE TO PRIOR APPLICATIONS
[0001] This application is a U.S. National Phase application under 35 U.S.C. §371 of International Application No. PCT/DE2013/100008, filed on Jan. 15, 2013 and which claims benefit to German Patent Application No. 10 2012 100 325.4, filed on Jan. 16, 2012. The International Application was published in German on Jul. 25, 2013 as WO 2013/107444 A1 under PCT Article 21(2).
FIELD
[0002] The present invention relates to the use of data about the force flow in a press for the operation of a plunger, wherein the press comprises at least one drive device connected via at least one drive train and generating a force, at least the plunger executing a stroke and transmitting the force and carrying at least one upper tool part and at least one bottom tool part associated with the plunger and the corresponding upper tool part, and wherein a workpiece or material is worked or deformed between the bottom tool part and the upper tool part.
[0003] For the purpose of the present invention, generic presses are presses with an upper drive and a bottom drive, but a distinction is made between special applications.
BACKGROUND
[0004] Embodiments of such presses with an upper drive and a bottom drive for the plunger have previously been described. For example, the respective element of the drive train connected to and driving the plunger can be designed as a tie rod/connecting rod in a bottom drive or as a threaded spindle in an upper drive or as an element, which directly generates a force such as a piston/cylinder unit.
[0005] In presses with a bottom drive, for example, the plunger can thus be driven by a compact drive unit in a sub-structure of the press by way of tie rods—also in conjunction with a connecting rod—or by way of threaded spindles serving as traction elements.
[0006] Irrespective of the type of the drive, a tilting of the plunger may occur due to eccentric forces acting during the machining process. Providing a parallel run of the plunger to the sub-structure is, however, often required.
[0007] To date, various solutions, which are substantially implemented by appropriate expenses for the drive the plunger or by different embodiments of the plunger guide, are used to achieve a required parallel operation.
[0008] It has proven disadvantageous, for example, that a complex but softly reacting kinematic lever system described in AT 215 257 B is inefficient for transmitting eccentric forces. When strong pressing forces are to be transmitted, the relatively numerous mobile machine elements generate only small compensatory movements for an efficient plunger stroke.
[0009] Presses (with an upper drive as well as with a bottom drive) must, however, be designed so that they can provide an optimized force and path progression of the plunger and its stroke and can act in a differentiated manner according to machining requirements. Positions of individual machine elements and of the plunger which deviate from normal positions must be absorbed and compensated for as much as possible by the structural system with regard to forces in order to avoid complex embodiments of the plunger guide on the one hand and to provide the machining process on the other hand.
[0010] It has already been proposed to record values about operating conditions in the system of the press during machining of the workpiece by means of a control and regulation device and to process them into data according to a function, so that the data is also usable to a limited extent for compensatory movements of the plunger. The press can thus be operated in a controlled or regulated manner according to a system of forces required for machining the workpiece.
[0011] In generic presses, the drawing process, e.g., by means of so-called drawing devices and drawing cushions, also has a decisive impact on the positions of the plunger with regard to its horizontal position.
[0012] In a punch press described in EP 2 008 799 A1 with a bottom drive, the plunger was driven by way of tie columns (similar to tie rods) by means of a drive mechanism with a crankshaft and connecting rod disposed below the machining level. Bearing loads are here to be reduced by means of a special transmission mechanism and a distribution of the plunger forces and a high precision is to be achieved at high frequencies. Positions of the plunger deviating from the horizontal are not, however, compensable.
[0013] With regard to current requirements for presses, wanted or unwanted compensatory movements occurring during the process must be possible. This aims at fulfilling the conditions for a practical operation in order to achieve a synchronous operation or compensatory movements of the plunger during at least a partial segment of its strokes.
[0014] In presses with a bottom drive, this thus also applies to the area of the articulation points of the tie rods to the plunger which are often designed as detachable, fixed connections to the plunger.
[0015] WO 2012/041313 described, in spite of occurring asymmetrical forces, such as e.g., in a drawing device, securing a guide so as to cause an originally desired movement of the plunger as well as movements of the upper tool part parallel to the bottom tool part, by way of separately operated drive trains having tie rods which independently apply forces to the plunger. Thus, on the one hand, a tilting of the plunger as well as various impacts of the plunger can be avoided and, on the other hand, the tilting of the plunger can be induced in a targeted manner.
[0016] It has thus already been proposed to use asymmetrically acting forces of the plunger in an advantageous manner and letting the plunger impact e.g., the drawing cushion device in parallel or, in the absence of a drawing cushion device, to drive the plunger with the upper tool part in parallel so that it bears down onto the bottom tool part. To this end, the e.g., two drive trains must be moved by different distances in the direction of the bottom dead center but without reaching it. A reversal (inversion of the rotational direction of the drive) and an upward movement of the plunger subsequently occur.
[0017] As an alternative, one drive train can even move through the bottom dead center and be moved back to the top dead center without a reversal, whereas the other drive train moves back to the top dead center before reaching the bottom dead center by way of a reversal. The respective position of the respective drive train is then decisive for generating the actually acting force.
[0018] DE 196 42 587 A1 described a multi-point press with hydraulic pressure pads and inversely adjustable spring stiffnesses of the pressure points for compensating for the tilting of the plunger in order to achieve a parallel positioning of the plunger in presses, which fulfills requirements such as:
reaction to eccentric loads without delay; precise operation; strong reliability; and simple, cost-effective structure.
[0023] Process disruptions resulting from a tilt of the table relative to the plunger or from eccentric loads on the plunger are therefore to be avoided in mechanically driven multi-point presses with eccentrically running work processes.
[0024] An aspect of the present invention is to compensate for the tilting of the plunger so that a plunger movement that is exactly parallel to the press table is for the most part provided.
[0025] Therefore, the principle of a solution includes:
a parallel positioning of the plunger in multi-point presses with hydraulic pressure pads, wherein the spring stiffnesses in the pressure points is modified so that different longitudinal deformations of the frame and connecting rod caused by eccentric loads are compensated for by a reduction of the stiffness of the associated pressure pad(s), to this end, the spring stiffness of the pressure points of the press is adjusted so that the total spring stiffnesses of the pressure points, obtained by adding up the spring stiffnesses of the individual pressure pads of the press and the spring stiffnesses of the associated elastically deformed machine parts, and the forces to be transferred by the individual pressure points of the press behave in inverse proportion relative to each other and the less loaded pressure pad(s) is connected to a pressure accumulator, more specifically, a piston accumulator and the preload pressure of the pressure accumulator, more specifically, the gas pressure of the piston accumulator, is adjusted according to the desired reduction of the stiffness of the associated pressure pad.
[0029] The problem “tilting of the plunger vs. parallel positioning of the plunger” is only seemingly solved by this synopsis of solutions according to this stage of development.
[0030] DE 10 2005 040 263 A1 described the problem of developing a method and a device for controlling and regulating the movement of the plunger in servo-electric presses in order to achieve a precise and repeatable sequence of the movement of the plunger in phases of a position-controlled as well as in phases of a force-controlled movement of the plunger. A controlled operation was meant to provide a high output between several plunger pressure points of one plunger as well as of several plungers of a press line, respectively, relative to each other and relative to peripheral devices.
[0031] The control accuracy of the tilt control in highly dynamic processes, usable in case of eccentric forces, of a plunger equipped with several pressure points was also meant to be improved.
[0032] In order to regulate the movement of the plunger, the central idea was to combine the principle of a main-shaft-controlled electronic cam disc adjustment with the force adjustment so that, depending on the operation mode, the phases of the movement of the plunger are controlled via electronic position cam discs and via a force adjustment or force limitation.
[0033] In addition to a compensation of the variable resiliency of all the drive elements located in the force flow occurring in case of an eccentric load, a tilt control of the individual pressure points was also meant to use the generation of a nominal tilt of the plunger, however, this position control occurred by means of the position cam disc and of a position offset.
[0034] From this teaching, the person skilled in the art could indeed gather, on the one hand, the idea of using all the drive elements located in the force flow for compensating the different resiliencies occurring under eccentric loads and, on the other hand, the idea of generating a nominal tilt of the plunger, but always provided that the nominal torques of the servomotors for driving the pressure point(s) of the plunger would be controlled as a function of influencing values such as gear ratio and/or resiliency by means of position cam discs controlled by a virtual main shaft and a force and moment limit value dependent on the operation mode.
[0035] Continuing this development, DE 10 2006 059 796 A1 describes a method and a device for controlling and regulating the drive system of a press in which the reproducibility of the quality of the formed parts to be produced is improved in spite of the effects of disruptive influencing values, the service life of the tools is increased, and the productivity is increased while simultaneously reducing the energy consumption.
[0036] To this end, the tilt of the plunger is controlled by a preset, servo-driven, position-adjusting device, separately associated with each pressure point. The person skilled in the art already recognized that the asymmetrical spring travels had to be determined by way of the eccentric load specific to each part while taking into account the stiffness model specific to the machine.
[0037] The actual compensation of the plunger tilt occurs, however, by way of a relatively complex target/actual comparison of the pre-set asymmetrical adjustment of the position of the plunger and the asymmetrical motion sequence of the servomotors for the main drive additionally associated with the pressure points.
[0038] During the 360° cycle mode, an tilting of the plunger at the top dead center is to be avoided according to a second embodiment by respectively traveling through the area of the top dead center in the cycle with a symmetrical adjustment of the position, the asymmetrical position adjustment being reactivated after the top dead center before the subsequent load phase.
[0039] In a third embodiment, the regulation of the tilt of the plunger is meant to take place so that during the load phase in the area in front of the bottom dead center, the position of the plunger or upper tool with regard to the tilting and deviation of the bottom dead center is recorded by means of a plunger position measuring device and the tilted position and, if necessary, the immersion depth is influenced in a control circuit.
[0040] According to a fourth embodiment, the immersion depth of the plunger is to be controlled. The expected variations of the reversal position of the plunger or tool are here stored in the control unit as a function of influencing values such as temperature changes and stroke rates conditioned by the operating time, while taking into account a model specific to the machine.
[0041] The central idea of these solutions is to influence, in a servo-electric forming press, the positional deviations of a plunger, drivable by means of a crank or a lever, caused by external and internal influencing values in a stroke-dependent operating mode when passing through the bottom dead center so that the immersion depth and the tilted position of the plunger is controllable or adjustable. However, using the cam disc regulation to control the servomotors for the main drive, which require separate electronic cam discs for each drive associated with each pressure point, is common to all four embodiments.
[0042] The person skilled in the art can see that the behavior of these presses is influenced in relation to a pre-set virtual main shaft, wherein the deviation of the individual servomotors from the pre-set main shaft position is to be influenced. This requires various preparation phases, which require a complex sequence for achieving a corresponding setting of the machine.
[0043] In view of these analyses, the problem of allowing the asymmetrically occurring press forces as well as drawing cushion forces to cause an unwanted tilting of the plunger such as caused by a malfunction or of counteracting it or of initiating a desired tilting of the plunger with simpler means such as available structural components, i.e., providing a desired parallel movement of the plunger by means of controlled and regulated drive motors, still remains.
[0044] A further development aiming at associating a cam disc regulation, with separate electronic cam discs for each drive, to the main drive is therefore ruled out.
[0045] The objective impact of Hooke's law in the constructional system of a press, according to which a tilting of the plunger due to eccentric forces generates different loads on the parts located in the force flow, which expand or compress or move differently according to Hooke's law as a function of the acting force, must therefore be more deliberately taken into account, amongst others, because complex structural additions can have a disadvantageous impact on the entire system.
[0046] The solution described by DE 196 42 587 A1 disadvantageously shows the person skilled in the art that it is only usable in a press that is driven by way of one drive and that the drive is distributed to several pressure points through a power distribution. It is thus not possible to influence the uniform or non-uniform forming process in any way by way of a control or adjustment of the drive.
[0047] Apart from these proposed solutions, sliding guides, for example, which are not adjustable or only adjustable along several axes, have been used for compensatory movements in presses. Complex rolling guides (roller bearing guides) are alternately also used, even in an elaborately pre-loaded state.
[0048] In order to prevent damage to these technical mechanisms in case of unexpected operating states, very complex protection mechanisms are therefore sometimes installed for preventing overloads.
[0049] The invention assumes that all these expenses and devices, such as guide and protection devices, can be dispensed with if the desired parallel movement of the plunger can be provided by controlled and regulated drive motors. In case of malfunctions, it must also be possible to allow a tilting or inclination of the plunger. Until now, solutions to this effect have not been covered by current developments and have been virtually excluded.
[0050] At the same time, the problem emerges of initiating a deviation from the desired parallel movement of the plunger, such as a tilting or inclination in a targeted manner, if expedient for the process, and of inducing such positions of the plunger by means of elements of the drives.
SUMMARY
[0051] An aspect of the present invention is to allow or counteract, in a press of the types described in the introduction, i.e., in presses with a top drive as well as presses with a bottom drive, an unwanted tilting of the plunger, such as caused by a malfunction, in case of asymmetrically occurring press forces as well as drawing cushion forces, or to trigger a desired tilting of the plunger by means of structural components, to which end data about the force flow in a press must be used for operating the plunger, without using complex protection mechanisms.
[0052] In an embodiment, the present invention provides a method of using data on a force flow in a press to operate a plunger, the method comprising providing the press. The press comprises a substructure. At least one drive device is arranged in the substructure. The at least one drive device is operatively connected to at least one drive train so as to generate a force. A plunger comprising at least one upper tool part is configured to execute a stroke and to transmit the force. At least one bottom tool part is associated with the plunger and with the at least one upper tool part. At least one traction element or pressure element is configured to act on the plunger via a traction connection or pressure connection which is configured to transmit a drive for the stroke of the plunger. The at least one traction element or pressure element and the traction connection or pressure connection is configured to produce a force flow from the drive device to the at least one upper tool part. The traction connection or pressure element and the at least one traction element or pressure element is mounted on the plunger in a traction/pressure point so as to allow for a tilting of the plunger. The traction/pressure point, due to elasticities of at least one traction element or pressure element, is configured to allow for a modifiable position which allows for a detachable configuration, a permanent configuration, or a fixed configuration of the traction connection or pressure connection. A workpiece or a material is worked or deformed between the at least one upper tool part and the at least one bottom tool part by the plunger and the at least one upper tool part being driven between a top and a bottom dead center in at least one single reversing stroke or in strokes passing through the bottom dead center and a top dead center so as to bear down onto the bottom tool part. Data on the force flow acting on and leading to an expansion, a compression, or a movement in an area of the traction/pressure point or of at least one traction element or pressure element in relation to the at least one drive device and a position of the plunger is recorded and analyzed so as to allow, counteract or initiate a tilting of the plunger for an operation of the press.
BRIEF DESCRIPTION OF THE DRAWINGS
[0053] The present invention is described in greater detail below on the basis of embodiments and of the drawings in which:
[0054] FIG. 1 shows a simplified representation of the press 1 with a bottom drive and a tie rod connection 2 . 4 . 1 and the schematic operation principle by means of a control and regulation device 4 as well as the means 4 . 1 , 4 . 2 , 4 . 3 ; and
[0055] FIG. 2 shows details of the tie rod connection 2 . 4 . 1 with the convex spherical segment bearings 2 . 4 . 2 and concave spherical segment bearings 2 . 4 . 3 in which each tie rod 2 . 1 . 2 is borne on the plunger 1 . 1 in a pressure point 2 . 4 .
DETAILED DESCRIPTION
[0056] In the present invention addresses these aspects based on the action of Hooke's law in the structural system of a press. According thereto, a tilting of the plunger caused by eccentric forces generates different loads acting on the parts located in the force flow which expand or compress or move according to Hooke's law as a function of the acting force.
[0057] Until now, such forces acting on components of the press were already being recorded and analyzed, but only for an immediate monitoring of the forming process of the workpiece between the upper tool part and the bottom tool part and in order to control excessive loads/loads with regard to the loads acting on the press and the tools.
[0058] The present invention discloses two embodiments, while taking into account that a looming tilting of the plunger due to eccentric forces causes different loads on the parts located in the force flow, which, according to Hooke's law, expand, compress, or move differently as a function of the acting force.
[0059] A first embodiment of the present invention additionally uses the data about these different expansions, compressions, or movements of the components and of the press in the force flow of the press for operating a plunger,
wherein the press comprises at least one drive device connected via at least one drive train and generating a force, at least the plunger executing a stroke and transmitting the force and carrying at least one upper tool part, and at least one bottom tool part associated with the plunger and the corresponding upper tool part, said parts of the press producing the force flow from the drive device to the upper tool part, wherein a workpiece or material is worked or deformed between the upper tool part and the bottom tool part, and the plunger with the upper tool part is driven between a top and a bottom dead center in at least one single reversing stroke or in strokes passing through the bottom dead center and the top dead center so that it bears down onto the bottom tool part,
[0062] so that
the data about different loads caused by eccentric forces acting on the entire force flow or an all the parts involved in the force flow, said forces causing an expansion or compression or movement of the involved parts according to Hooke's law, is recorded and analyzed in relation to the drive device ( 2 ) and to the position of the plunger ( 1 . 1 ), whereupon,
a tilting of the plunger ( 1 . 1 ) is allowed, or a tilting of the plunger ( 1 . 1 ) is counteracted, or a tilting of the plunger ( 1 . 1 ) is initiated,
[0068] for operation.
[0069] As opposed in particular to DE 196 42 587 A1, the present invention achieved that generic presses can be operated by way of two drive units. It is thus possible to influence the synchronous operation of the plunger by means of a control and regulation of the drives. Data about both drives can here be recorded in order to derive decision criteria for the control and regulation process, wherein all the components or drives involved in the force flow are taken into account.
[0070] A second embodiment of the present invention uses the data about the force flow of a press for the operation of a plunger,
wherein the press comprises at least one drive device disposed in a sub-structure and connected via at least one drive train and generating a force, at least the plunger executing a stroke and transmitting the force and carrying at least one upper tool part, and at least one traction element or pressure element acting on the plunger by means of a traction connection or pressure connection for transmitting the drive for the stroke of the plunger, and at least one bottom tool part associated with the plunger and the corresponding upper tool part, said parts of the press producing the force flow from the drive device to the upper tool part, wherein a workpiece or material is worked or deformed between the upper tool part and the bottom tool part, and the plunger with the upper tool part is driven between a top and a bottom dead center in at least one single reversing stroke or in strokes passing through the bottom dead center and the top dead center so that it bears down onto the bottom tool part,
[0073] so that
the traction connection with the traction element or the pressure connection with the pressure element is mounted on the plunger in a traction/pressure point allowing for a tilting of the plunger, data about the force flow acting there and leading to an expansion or a compression or a movement in the area of the traction/pressure point or of the traction element or the pressure element is recorded and analyzed in relation to the drive device and the position of the plunger, whereupon,
a tilting of the plunger ( 1 . 1 ) is allowed, or a tilting of the plunger ( 1 . 1 ) is counteracted, or a tilting of the plunger ( 1 . 1 ) is initiated,
[0080] for operation.
[0081] In an embodiment of the present invention, the traction element can, for example, be configured as a tie rod or feed rod. In an embodiment of the present invention, the pressure element can, for example, be configured as a connecting rod or a shaft or a piston/cylinder unit.
[0082] In an embodiment of the present invention, an arrangement of the traction connection or of the pressure connection can, for example, advantageously be used for the second embodiment in the traction/pressure point, each having a convex spherical segment bearing and a concave spherical segment bearing corresponding to each other in the manner of a calotte and allowing for an articulately changeable bearing of the traction element or pressure element, wherein compensatory forces/movements are absorbed by the spherical segment bearings.
[0083] In an embodiment of the present invention, a detachable or permanent or fixed arrangement of the traction connection or of the pressure connection can, for example, be alternately used in the traction/pressure point, which allows a modifiable position due to acceptable resiliencies of the traction element or pressure element, wherein compensatory forces/movements are then elastically absorbed by the traction element or the pressure element.
[0084] In an embodiment of the present invention, the data can, for example, be analysed in a relation according to Hooke's function F=D×Δ, wherein F refers to the force, D to a spring constant, and Δ is the distance of expansion or compression.
[0085] In an embodiment of the present invention, at least one first means can, for example, be used for recording data about a displacement or the stroke with regard to the position of the plunger.
[0086] In an embodiment of the present invention, at least one second means can, for example, be provided for analyzing data about at least one of the states or one of the functions such as:
the position of the plunger, the force flow of the involved parts, for a targeted tilting of the plunger.
[0090] In an embodiment of the present invention, at least one third means can, for example, be responsible only for recording data about the force flow of the involved parts.
[0091] In an embodiment of the present invention, in order to record the data about parts subjected to an expansion or a compression or a movement, at least one element recording a force or movement can, for example, be provided in at least one part of the press, wherein said element can, for example, be fastened in the force- or movement-sensitive areas of the expansion or compression or articulately modifiable bearing of the traction element or pressure element and is configured as a piezo-element, a strain gauge or a similarly acting element.
[0092] In an embodiment of the present invention, a control and regulation device can, for example, process the data of the first, second and third means for at least one of the control signals such as:
allowing a tilting of the plunger, counteracting a tilting of the plunger, or initiating a tilting of the plunger,
[0096] for operating the plunger.
[0097] In an embodiment of the present invention, an integration of at least the first means or the second means or the third means can, for example, take place for a controlled or regulated process sequence, wherein a relation is established between the data about occurring deformation forces processed by the second means or third means and the data about the position of the plunger detected by the first means or the second means.
[0098] In an embodiment of the present invention, the data detected by the second means or the third means and the data about the position of the plunger detected by first means can, for example, be controlled/regulated as reference values in the process operation in such a manner that the desired force flow/force compensation is implemented.
[0099] In an embodiment of the present invention, the detected data about the position of the plunger can, for example, also be provided as reference values, according to which the desired force flow/force compensation is adjusted.
[0100] In an embodiment of the present invention, the reference values based on the detected data about the force flow of the involved parts or the deformation forces and the reference values based on the detected data about the position of the plunger can, for example, be changed during the process operation.
[0101] In an embodiment of the present invention, the data resulting from the forces or positions of the plunger, which respectively change during the process, can, for example, be processed by at least one of the first, second and third means.
[0102] As a whole, the present invention establishes a relation between the respective drive devices and the monitored position of the plunger based on this data, analyses this relation, and can influence a tilting of the plunger in a targeted manner in spite of different forces and thus different compressions of the components, so that a tilting of the plunger is deliberately allowed or counteracted or initiated in the operation.
[0103] The present invention therefore provides a solution that is respectively useful for a targeted tilting of the plunger or for a tilting of the plunger that is to be accepted as well as for one that results from a malfunction.
[0104] The present invention is thus applicable in presses with a top drive as well as for presses with a bottom drive, wherein “quasi-sensory means” for recording data about the parts involved in the force flow can be parts, that can, for example, be located in areas that are relevant to the force flow and sensitive to the components, such as e.g., a pressure or traction connection (respectively in a top or bottom drive) with the plunger.
[0105] In a press with a bottom drive, it can, for example, be advantageous to provide an arrangement of the traction connection in the traction/pressure point having a convex spherical segment bearing and a concave spherical segment bearing corresponding to each other in the manner of a calotte.
[0106] This arrangement of the traction connection in the traction/pressure point having a convex spherical segment bearing and a concave spherical segment bearing corresponding to each other in the manner of a calotte can, however, also be used as a pressure connection in a press with a top drive.
[0107] This structure according to the invention can be implemented e.g., in a generic press with a bottom drive as described in PCT/DE2011/075197, which already uses data for a force-optimized process operation.
[0108] However, to date, this data merely relates to:
a course or a position in the stroke of the plunger, an actual value of a force or a force-equivalent value in at least one of the drive elements of the drive device, values of a power consumption, a torque, an electric current, a rotational speed or a rotation angle of at least one drive element such as a motor or servomotor, an actual value of an output or output increase in the system of the press,
[0113] which are functionally processed in a control and regulation device, e.g.,
for modifying values that are to be adjusted or set for operating the press, for overload protection, emergency operation or shutdown of the press and/or for a synchronous or asynchronous run of drive elements of the drive device
[0117] for operating the press.
[0118] The present invention can be integrated into this prepared system with a marginal effort so that it is technologically easily implementable.
[0119] If the present invention is used, the area of the tie rod connection with the plunger, i.e., the traction/pressure point used as a “quasi-sensory means”, can, for example, be equipped with strain gauges or piezo-elements for recording the data.
[0120] In this regard, the development according to the present invention, namely the control and regulation device protecting the mechanical structure of the press and providing the compensation of asymmetrical press forces as well as processing data from the first, second and third means, is also insertable into an existing system configured as proposed above.
[0121] A controlled or regulated process sequence can thus be defined, for example, during forming by taking into account at least the first means or the second means or the third means. In doing so, a relation is established between the data about occurring forming forces processed by the second means or third means and the data about the position of the plunger detected by the first means or the second means.
[0122] In view of the issue presented above, the teaching according to the present invention also allows initiating asymmetrical press forces and drawing cushion forces in a targeted manner, for example, in a press with a bottom drive, by way of tie rods not rigidly connected with the plunger in four pressure points, the possible movable bearing in respectively one calotte and the definable tilting of the plunger also serving to this end.
[0123] In general, in generic presses, regardless of whether it has a top drive or a bottom drive, once the upper tool part has borne down on e.g., a workpiece holder of e.g., a drawing cushion, or after the plunger as borne down on the bottom tool part, the different forces resulting from the tilting will be easier to adjust in the press of the machine by means of the present invention, according to the rotational angle of the eccentric and the spring constant, i.e., according to Hooke's law.
[0124] In particular in a press with a bottom drive implemented as described, for example, in PCT/DE2011/075197, pressure points as well as, according to a kinematic reversal, traction points act on the tie rod connections used therein, which is why this area of the tie rod connections is referred to as “traction/pressure points” herein. Indeed, according to the present invention, the force application occurring there has different causes, namely, an oblique or inclined position of the plunger caused by a malfunction of the press or controlled in a targeted manner. For both causes, the present invention provides a uniformly effective advantage regarding elements such as the guide, the adjusting mechanism of the plunger and the overload protection. Since the application of a force on the pressure point can come e.g., from a connecting rod disposed above it (as in a press with a top drive) and the press force is transmitted via e.g., a transverse bolt to a threaded spindle, which is part of a pressure point, the length of said threaded spindle would be decisive for a potential adjustment of the plunger. A necessary consequence of this arrangement determined by the geometry of the press would be that the length of the spindles and thus the height of the plunger adjusting mechanism would be disadvantageous to the height of the press. In contrast, by using a traction point in combination with a pressure point, this disadvantage of having to factor the spindle length into the height of the entire machine can be eliminated a priori by the use according to the present invention and the tilt or tilting of the plunger, e.g., initiated in a targeted manner, can be additionally controlled to an almost unlimited extent.
[0125] In this regard, the present invention provides an additional effect which has an impact not only on the interaction of the deformation forces as well as the drawing cushion forces but also advantageously on the structural complexity of generic presses and more specifically on an optimized design of the hydraulic components when using a drawing cushion.
[0126] The principle of the present invention can therefore also be integrated or retrofitted with little effort into available control and regulation systems of the involved drives.
[0127] The present invention is hereafter described based on an exemplary embodiment, for example, in a press with a bottom drive, by means of the drawings.
[0128] FIG. 1 shows a press 1 with a bottom drive, whose drive device 2 disposed in a sub-structure 3 comprises eccentric drive elements 2 . 1 , motors or servomotors 2 . 2 , tie rods 2 . 3 and connecting rods 2 . 5 . A plunger 1 . 1 executing a stroke h between a top dead center (not labeled) and a bottom dead center (not labeled) has an upper tool part 1 . 2 . Two pairs of tie rods 2 . 3 and connecting rods 2 . 5 as part of a drive train 2 . 6 act on the plunger 1 . 1 , respectively, in the area of a traction/pressure point 2 . 4 for transmitting the drive for the stroke h of the plunger 1 . 1 . The plunger 1 . 1 with the upper tool part 1 . 2 corresponds to a bottom tool part 3 . 2 disposed on the substructure 3 , wherein the upper tool part 1 . 2 acts onto a workpiece 5 located on the bottom tool part 3 . 2 for forming. The bottom tool part 3 . 2 is disposed on a table 3 . 1 belonging to the substructure 3 .
[0129] A control and regulation device 4 , whose operation can be designed according to the system described in PCT/DE2011/075197, is provided for operating the press 1 . By way of the tie rods 2 . 3 and the connecting rod 2 . 5 , forces acting in a differentiated manner are applied to the workpiece 5 to be formed between the upper tool part 1 . 2 and the bottom tool part 3 . 2 so that the press 1 can be permanently operated according to a system of forces required exclusively by the workpiece 5 , but still without the use of a traction connection 2 . 4 . 1 disclosed according to the invention.
[0130] The press 1 operating according to that system takes sequences into consideration, in terms of control, which are usable for the new inventive process according to the features disclosed in the claims on the one hand and which transcend them in terms of their effects.
[0131] This proposed control solution and the complex operational and constructional design required for it can be assisted on the one hand by generating the force actually acting in each respective position of the respective drive train 2 . 6 or of e.g., an eccentric drive element 2 . 1 of the drive device 2 and on the other hand by using the data in consideration of Hooke's law in accordance with the invention.
[0132] Based on a press 1 designed in such a manner, the present invention goes beyond that and solves the issue presented in the introduction and the problem of tilted or inclined positions of the plunger, i.e., when the position of the plunger 1 . 1 deviates from a normal parallel operation, in accordance with the following new example.
[0133] A force compensation caused by opposing, returning forces (Hooke's law) countering the deformations initiated in the constructional system of the press 1 by the asymmetrically acting forces is initiated by an interaction between the involved deformation forces, a rotation angle and a spring constant or at least respectively one of these dimensions of at least one machine element of the press 1 in relation with its constructional stiffness or of an eccentric element of the drive device 2 .
[0134] To this end, the traction connection 2 . 4 . 1 non-rigidly borne in a traction/pressure point 2 . 4 allowing a modifiable position between the plunger 1 . 1 and the tie rod 2 . 3 is used, which means that this area is used as a “quasi-sensory means” and is re-constructed in a surprisingly functional new manner.
[0135] It is alternately possible to choose an arrangement of the traction connection 2 . 4 . 1 that is rigid due to acceptable elasticities.
[0136] Whether the tilted or inclined position of the plunger 1 . 1 is caused by a malfunction of the press 1 or is initiated in a targeted manner, the force compensation is respectively supported, optimized or implemented by means of data to be recorded or to be input in the area of the traction/pressure point 2 . 4 . To this end, the non-rigid traction connection 2 . 4 . 1 is borne in the traction/pressure point 2 . 4 in an arrangement having, respectively, one convex spherical segment bearing 2 . 4 . 2 and one concave spherical segment bearing 2 . 4 . 3 corresponding to each other in the manner of a calotte.
[0137] If the tilted or inclined position of the plunger 1 . 1 is caused by a malfunction of the press 1 , a first means 4 . 1 records the data about this position of the plunger 1 . 1 , which is input in order to support the force compensation and to preserve the operation of the construction system of the press 1 .
[0138] If the tilted or inclined position of the plunger 1 . 1 is to be controlled in a targeted manner, a second means 4 . 2 provides the data for this desired position of the plunger 1 . 1 , whereby, a resulting unequal movement of the two drive trains 2 . 6 is continued, e.g., after the upper tool part 1 . 2 has borne down onto the bottom tool part 3 . 2 . The upper tool part 1 . 2 and the bottom tool part 3 . 2 are now closable in a parallel relation, wherein asymmetrical and unequally acting forces are generated in a targeted manner by the unequally continuing movement and the spring stiffness of the press 1 .
[0139] In this example, third means 4 . 3 provide for a recording of data about the force flow by way of a force/displacement recording mean 2 . 4 . 4 .
[0140] The control and regulation device 4 provided for operating the press 1 processes the data from the first, second and third means 4 . 1 , 4 . 2 , 4 . 3 for protecting the mechanical structure of the press and for a compensation of the asymmetrical press forces and provides control signals such as:
allowing a tilting of the plunger, or counteracting a tilting of the plunger, or initiating a tilting of the plunger.
[0144] During forming, the third means 4 . 3 thus establishes and adjusts a relation between the occurring forces (deformation forces) in the force flow and the position of the plunger 1 . 1 based on the data about the traction/pressure point 2 . 4 , respectively, from the first means 4 . 1 in case of a malfunction of the press 1 or from the second means 4 . 2 in case of a tilted or inclined position of the plunger 1 . 1 initiated in a targeted manner.
[0145] The data obtained from the respective deformation force is then used as a reference value and the position of the plunger 1 . 1 is guided so that a desired force flow is implemented. The force compensation preserving the constructional system of the press 1 is thus optimized or carried out.
[0146] Data gathered from the position of the plunger 1 . 1 can also play a decisive role as reference values.
[0147] The force compensation controlled in such a manner during the forming process based on the data detected in the traction/pressure point 2 . 4 by means of the “quasi-sensory means” also considers the fact that the respective forces or positions of the plunger 1 . 2 change and that the respective reference values derived from the force or the position of the plunger 1 . 1 can vary.
[0148] Known force/displacement recording means 2 . 4 . 4 such as strain gauges or piezo-elements or similarly acting means, which can be chosen by the person skilled in the art in the usual manner, can be used for recording the data in the area of the traction/pressure point 2 . 4 .
[0149] The design of the first, second and third means 4 . 1 , 4 . 2 , 4 . 3 is also chosen by the person skilled in the art in a customary manner and does not have to be described in more detail herein.
[0150] The principle according to the invention is also applicable in a press with a top drive, not explained here, in which the force flow occurs from a drive device disposed at the top via a plunger with an upper tool part to a bottom tool part by way of a pressure connection. The plunger with the upper tool part can here too be moved between a top and a bottom dead center in at least one single reversing stroke or in strokes passing through the bottom dead center and the top dead center, so that it bears down on the bottom tool part.
[0151] The use of data about the force flow in that press for operating a plunger occurs so that in case of a tilting of the plunger caused by eccentric forces and of different resulting loads on the parts involved in the force flow, which are also subject to an expansion or a compression as a function of the respectively acting force according to Hooke's law, the data is recorded and analysed in relation to the drive device and the position of the plunger, whereupon:
a tilting of the plunger is allowed, or a tilting of the plunger is counteracted, or a tilting of the plunger is initiated.
[0155] In an application according to the present invention, the parts involved in the force flow can be connecting rods or spindles, which act on the plunger in a pressure point and which are connected in that point with the plunger. In the area of said pressure point, similar force/displacement recording means 2 . 4 . 4 , such as strain gauges or piezo-elements or similarly acting means, are used for recording the data about the force flow.
[0156] The use of data in a press according to the invention can be implemented on the one hand in existing basic systems without a substantial construction effort on the one hand and ensure on the other hand:
an allowable tilting, or a counteraction of the tilting, or a targeted initiation of a tilting,
[0160] of the plunger and supports the efficiency of acting forces for an energy-saving operation of any generic press.
[0161] The present invention is not limited to embodiments described herein; reference should be had to the appended claims.
LIST OF REFERENCE NUMBERS
[0000]
1 press
1 . 1 plunger
1 . 2 upper tool part
2 drive device
2 . 1 eccentric drive element
2 . 2 motor or servomotor
2 . 3 traction element, tie rod, feed rod (bottom drive), pressure element, spindle, piston/cylinder unit (top drive)
2 . 4 traction/pressure point
2 . 4 . 1 traction connection (bottom drive), pressure connection (top drive)
2 . 4 . 2 convex spherical segment bearing
2 . 4 . 3 concave spherical segment bearing
2 . 4 . 4 force/displacement recording means
2 . 5 connecting rod
2 . 6 drive train
3 substructure
3 . 1 table
3 . 2 bottom tool part
4 control and regulation device
4 . 1 first means for recording data about the position of the plunger ( 1 . 1 )
4 . 2 second means for recording data
4 . 3 third means for recording data about the force flow
5 workpiece
h stroke | A method of using data on the force flow in a press for the operation of a plunger, wherein the loads of the parts involved in the force flow can differ as a result of eccentrically operating forces, in such a way that the data about the respectively acting forces that, in accordance with Hooke's law, cause an extension or compression of a movement of the parts involved in the force flow, is measured and evaluated in relation to a drive device and a position of the plunger, whereupon a skewed position of the plunger is permitted or a skewed position of the plunger is counteracted or a skewed position of the plunger is set during operation of the press. | 1 |
RELATED APPLICATIONS
This application is a U.S. National Stage application under 35 U.S.C. §371 of PCT Application PCT/US2013/024552 (filed Feb. 3, 2013), which is incorporated here by reference in its entirety.
FIELD OF THE INVENTION
This application generally relates to photovoltaic (PV) systems and more particularly to methods and apparatus for photovoltaic energy extraction.
BACKGROUND
As is known in the art, asymmetries in a photovoltaic (PV) string caused by temperature variation, dirt, panel aging, panel orientation, and other factors can negatively impact tracking efficiency. To maximize energy extraction, distributed power conversion is employed to enable per-panel or sub-panel maximum-power-point tracking (MPPT). There are essentially three common architectures deployed in residential and commercial PV installations for delivering power to the grid: (1) string inverter, (2) micro-inverter, and (3) DC-DC series power supplies working in concert with a string inverter. Each of these architectures has limitations.
For example, the existing approaches are typically constructed with magnetic components, possibly purchased on a per-panel basis. Even at high switching frequencies where magnetic component size can be minimized or eliminated by using air core or parasitic wire inductance, these components constrain manufacturing cost. High frequency switching may also complicate electromagnetic interface created by the distributed converters, as the frequencies approach allocated FCC bands.
SUMMARY
The circuits, systems and techniques described herein can overcome the limitations of the prior art techniques.
In one aspect, described herein is a method and apparatus for per-panel photovoltaic energy extraction with integrated converters. It has been recognized that this approach can increase overall array tracking efficiency.
It has also been recognized that such a system architecture can be implemented at all levels in a photovoltaic (PV) array: for the panels, for the overall control, and for the interface to the utility.
Also described is a grid-tie inverter interface with SC DC-DC MICs.
In accordance with a further aspect of the circuits, systems and techniques described herein, a solar cell circuit includes a solar cell; and a switched-capacitor DC-DC converter deployed with the solar cell during or after manufacturing of the cell and wherein said switched-capacitor DC-DC converter is provided having a plurality of conversion levels and wherein the switched-capacitor DC-DC converter is provided having a conversion level selected such that a current provided by the solar cell is close to the maximum power current of the solar cell.
In one embodiment, the switched-capacitor DC-DC converter is partially or fully integrated with the solar cell using an integrated circuit manufacturing process.
In one embodiment, the integrated portions of the DC-DC converter can be manufactured on the same substrate material as the solar cell.
In accordance with a further aspect of the circuits, systems and techniques described herein, a solar sub-module string comprising a plurality of solar cell circuits each of the plurality of solar cell circuits comprising: a solar cell; and a switched-capacitor DC-DC converter deployed with the solar cell during or after manufacturing and wherein said switched-capacitor DC-DC converter is provided having a plurality of conversion levels and wherein the switched-capacitor DC-DC converter is provided having a conversion level selected such that a current provided by the solar cell is close to the maximum power current of the solar cell; and a switched-capacitor DC-DC converter deployed with the plurality of solar cell circuits and wherein said switched-capacitor DC-DC converter is provided having a plurality of conversion levels and wherein the switched-capacitor DC-DC converter is provided having a conversion level selected such that a current provided by the plurality of solar cell circuits is close to the maximum power current of the plurality of solar cell circuits; and wherein each of the plurality of solar cell circuits are coupled to provide the solar sub-module string.
In accordance with a further aspect of the circuits, systems and techniques described herein, a photo-voltaic (PV) module includes: a plurality of solar sub-module strings each of the plurality of solar sub-module strings comprising: a plurality of solar cell circuits; and a switched-capacitor DC-DC converter deployed with the plurality of solar cell circuits and wherein said switched-capacitor DC-DC converter is provided having a plurality of conversion levels and wherein the switched-capacitor DC-DC converter is provided having a conversion level selected such that a current provided by the plurality of solar cell circuits is close to the maximum power current of the plurality of solar cell circuits; and a switched-capacitor DC-DC converter deployed with the plurality of solar sub-module strings and wherein said switched-capacitor DC-DC converter is provided having a plurality of conversion levels and wherein the switched-capacitor DC-DC converter is provided having a conversion level selected such that a current provided by the plurality of solar sub-module strings is close to the maximum power current of the plurality of solar sub-module strings; and wherein each of the plurality of solar cell circuits are coupled to provide a plurality of solar sub-module strings and each of the plurality of solar sub-module strings are coupled to provide the PV module.
In accordance with a further aspect of the circuits, systems and techniques described herein, a grid-tie inverter for coupling a PV array to a power grid, the grid-tie inverter comprising: an MPPT tracking loop; an energy balance control loop; and means for providing output current amplitude control, said means for providing current amplitude control comprising: a feed-forward path comprising means for determining a feed-forward term; and a feedback patch comprising means for determining a feedback term.
In one embodiment, the grid-tie inverter further includes means for decoupling the MPPT tracking loop and the energy balance control loop such that the system operates more stably by relying more heavily on a feedforward term generated by the means for determining a feed-forward term than a feedback term generated by the means for determining a feedback term.
In accordance with a still further aspect of the circuits, systems and techniques described herein, a grid-tie inverter for coupling a PV array to a power grid, the grid-tie inverter comprising: an MPPT tracking loop; an energy balance control loop; and a switched-capacitor energy buffer; and means for providing output current amplitude control, said means for providing current amplitude control comprising: a feed-forward path comprising means for determining a feed-forward term; and a feedback patch comprising means for determining a feedback term.
In one embodiment, the grid-tie inverter further includes means for decoupling the MPPT tracking loop and the energy balance control loop such that the system operates more stably by relying more heavily on a feedforward term generated by the means for determining a feed-forward term than a feedback term generated by the means for determining a feedback term.
In one embodiment, the MPPT tracking loop is controlled by an input current sink.
In one embodiment, the feedforward path can force a resample mid-cycle (at the price of non-unity power factor for one cycle) to prevent an energy buffer capacitor voltage from running out of range and wherein the forced resample may be triggered by passing a PV array voltage through a high-pass filter and level detectors to check for sudden large steps in input power.
In one embodiment, the control of the switched-capacitor energy buffer can be derived from the measured input power from the PV array without the need of a pre-charge circuit and wherein the charge and discharge cycles of a capacitor is only permitted when the said capacitor's voltage is within the maximum and minimum bounds derived from the measured input power from the PV array.
Switched-capacitor (SC) techniques have been proposed for energy buffering applications between DC and AC grids. These techniques have been implemented using film or ceramic capacitors and have been shown to achieve high energy utilization and comparable effective energy density to electrolytic capacitors. Practical applications require control schemes capable of handling transients. Described herein concepts, systems, circuit and techniques which consider tradeoffs regarding circuit topology, switching configuration, and control complexity. In one embodiment, a two-step control methodology that mitigates undesirable transient responses is described.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing features of the concepts, systems, circuits and techniques described herein may be more fully understood from the following description of the drawings in which:
FIG. 1 is a block diagram of a model of a linearized discrete conversion ratio integrated converter.
FIG. 2 illustrates quantization steps for a cell-level integrated converter.
FIG. 3A is a plot of tracking efficiency vs. number of cells in a sub-module string with and without integrated converters using a 5% variation in maximum-power current.
FIG. 3B is a plot of tracking efficiency vs. number of cells in a sub-module string with and without integrated converters using a 10% variation in maximum-power current.
FIG. 4A is a diagrammatic view of a sub-module string having a conventional layout.
FIG. 4B is a diagrammatic view of a sub-module string having a common centroid layout.
FIG. 5 shows MATLAB simulation results comparing the two layout schemes shown in FIGS. 4A and 4B . Simulated standard deviation distribution (normalized to the maximum power of one solar cell) of maximum power for 3 strings of 6 cells.
FIG. 6 is a statistical percentage power variation vs. output power of maximum power string.
FIG. 7 is an expected percentage power variation vs. number of cells per sub-module string.
FIG. 7A is a flow diagram of an exemplary Maximum Power Point Tracking (MPPT) process.
FIG. 8 is a connection diagram depicting the experimental setup for the series connection of MICs and PV circuit models.
FIGS. 9A and 9B show experimental data:
FIG. 10 is a recommended gate drive adapted from IR AN-978
FIG. 11 is a tunable zener diode biasing circuit using ground-referenced MOSFETs.
FIG. 12 is an active current source zener diode biasing circuit.
FIG. 13 is a block diagram of a centralized inverter.
FIG. 14 is a grid-tie inverter model.
FIG. 15 is a model for calculating the output impedance of a constant power grid-tie inverter.
FIG. 16 is an approximate output Impedance normalized to
1 c 0 = V s 2 2 P i n
for different feedback gain k.
FIG. 17 is a switched-capacitor energy buffer implementation.
FIG. 18 is a switched-capacitor charge and discharge waveforms.
FIGS. 19A, 19B and 19C are overall system-level block diagrams and control schemes implemented in SPICE simulation. FIG. 19A is a system overview of the simulated circuit, FIG. 19B is an energy balance controller with feedforward forced resampling, FIG. 19C illustrates preliminary switched-bus-capacitor control logic.
FIGS. 20A-20C are a series or plots illustrating system voltages V C,0 , V bus , V c,1 and current I(L 1 ) in response to an Input voltage step from 40V to 100V and i mppt =4 A which occurs after 150 ms.
FIG. 21 is a block diagram of a general architecture of an SC energy buffer.
FIG. 22A is a plot of Vbus and Vfb vs. time.
FIG. 22B is a plot of FSM state vs. time which illustrates a transient bus voltage response of a 2-6 SC energy buffer in a PFC due to a 30% load power step.
FIGS. 23A, 23B are plots of support voltages and buffer voltage vs. time which illustrate a transient bus voltage response of a 1-8 SC energy buffer in a solar inverter due to a 30% input power step
FIG. 24A is block diagram of a 1-z architecture of an SC energy buffer implemented with ground-referenced switches only for unipolar switching configuration.
FIG. 24B is a block diagram of a 1-z architecture of an SC energy buffer implemented with four additional switches (as compared with the FIG. 24A implementation), to achieve bipolar switching configuration.
FIG. 25A is a plot of overall energy utilization (in percent) of an SC energy buffer with bipolar switching configuration versus different numbers of backbone and supporting capacitors for a 10% peak-to-peak ripple.
FIG. 25B is a plot of overall energy utilization (in percent) of an SC energy buffer with bipolar switching configuration versus different numbers of backbone and supporting capacitors for a 5% peak-to-peak ripple.
FIG. 25C is a plot of overall energy utilization (in percent) of an SC energy buffer with bipolar switching configuration versus different numbers of backbone and supporting capacitors for a 2% peak-to-peak ripple.
FIG. 26A is a plot of sampling points and control variables, v c (i) and v d (i), in relation to the ripple cycle and the control ramps for a unipolar switching configuration.
FIG. 26B is a plot of sampling points and control variables, v c (i) and v d (i), in relation to the ripple cycle and the control ramps for a bipolar switching configuration.
FIG. 27A is a plot of peak-to-peak ripple vs. power level which illustrates expected ripple magnitude vs. power level for a 1-8 unipolar design example.
FIG. 27B is a plot of supporting capacitor voltages (V) vs. power level (watts) for a 1-8 unipolar design example.
FIG. 28 is a block diagram of a two-level SC energy buffer controller, where v 0 denotes the backbone capacitor voltage, v i [n] for i={1, 2, . . . , N−1} and v c denotes the sampled supporting capacitor voltage, and v d corresponds to the charge and discharge control signals respectively.
FIGS. 29A, 29B are plots of voltage (V) vs. time (seconds) which illustrate steady-state bus voltage waveforms of a 1-9 SC energy buffer with unipolar switching.
FIGS. 29C, 29D are plots of voltage (V) vs. time (seconds) which illustrate steady-state bus voltage waveforms of a 1-4 bipolar SC energy buffer with bipolar switching.
FIGS. 30A, 30B are plots of voltage (V) vs. time (seconds) which illustrate a transient bus voltage response of a 1-4 bipolar SC energy buffer in a solar inverter due to 30% input power step.
FIG. 31 is a circuit diagram of an exemplary SSC energy buffer circuit referred to as a 2-6 bipolar SSC energy buffer circuit.
FIG. 32 is a plot which illustrates which states, individual capacitor voltages, and resulting bus voltage over a charge and discharge cycle of the 2-6 bipolar SSC energy buffer of FIG. 4 .
FIG. 33 is a circuit diagram of a generalized example of an SSC energy buffer circuit referred to as an n-m bipolar SSC energy buffer circuit.
FIGS. 34A, 34B, and 34C are a series of plots illustrating Energy buffering ratio (Γ b ) as a function of the number of backbone capacitors n and number of supporting capacitors m for different values of voltage ripple ratio: (a) Rv=5%, (b) Rv=10% and (c) Rv=20%.
FIGS. 35A and 35B are block diagrams of a setup comprising a power factor correction (PFC) ac-dc converter, a dc load and an SSC energy buffer comprising an SSC energy buffer power circuit, a precharge circuit, and a control unit;
FIG. 36 is a schematic diagram of a a 2-6 bipolar SSC energy buffer having a precharge circuit coupled thereto.
FIG. 37 is a flow chart illustrating control logic during precharge and normal operation of a 2-6 bipolar SSC energy buffer.
DETAILED DESCRIPTION
Referring now to FIG. 1 , a model of a linearized discrete conversion ratio integrated converter includes a source coupled to a plurality of photovoltaic (PV) elements PV 1 -PV N through a like plurality of converters. It should be noted that each photovoltaic (PV) element PV 1 -PV N can represent either a PV cell, a sub-module PV string, or a PV module.
The drive to miniaturization has renewed interest in capacitor-based switching power conversion due to higher energy storage density of capacitors compared to inductors.
It has been shown that outstanding MPPT and overall system efficiency can be achieved using a modified version of a DC-DC module integrated converter, where the DC-DC converters are switched-capacitor converters that can only achieve integer or rational multiples of the input voltage from a photovoltaic module. This approach may be cost-attractive and physically rugged because it requires no per-panel magnetic components.
Switched-capacitor MICs may not be most efficiently deployed as current sources contributing to the string. However, in contrast to the typical DC-DC MICs that operate with local autonomous MPPT control, the proposed system shares the responsibility of MPPT with one centralized inverter. Specifically, the central inverter can be input-current-controlled so that it appears as a current sink to all the MICs in the string. The load current can then be scaled by the module-level converter to become a scaled current sink at the sub-module levels.
Sources of Variation in a PV String
The different types of variations that cause asymmetries in a PV string can be broadly classified into two categories: process variation and external operating condition.
Process variation in the solar industry typically refers to manufacturing I-V mismatch between solar cells. Low-level solar module construction faces similar tracking efficiency challenges as high-level solar array assembly. Solar cells that are connected in series must all carry the same current. Thus, they do not perform at their individual maximum power points. Instead, they operate at a collective maximum that is limited by the mismatch between cells within the module. The tracking efficiency at the cell level, also known as the mismatch factor, can be defined as
η
p
,
cell
=
P
collective
,
max
∑
P
i
,
cell
,
max
(
1
)
In order to reduce the amount of cell-to-cell variation and increase the cell tracking efficiency, the solar panel manufacturers have invested greatly in improving their manufacturing process as well as evaluating different cell binning algorithms. Historically, manufacturers have refined production processes and reduced the power tolerance from ±10% down to ±3%. However, it is worth noting that current and voltage parameters can have higher tolerance in the case of sorting by maximum power as manufacturers typically sort the cells into different power bins to sell at different price points. Described herein is a beneficial (in some cases, optimal) series-parallel layout configuration to increase (and ideally, maximize) output power of PV modules at a given confidence level.
External operating conditions consist of environmental factors including irradiance level, shading, temperature variation, dirt collection, panel aging, and panel orientation. Unlike process variation, which is tightly controlled in the manufacturing process, environmental factors can introduce large systematic imbalance (panel aging, panel orientation) or can unpredictably change the individual solar module's maximum power point substantially (irradiance level, shading). For example, shading of a solar module can change a module's maximum power by as much as 100%. In addition, in a residential installation, panels may be placed on both sides of the roof, meaning that panels have two distinct orientations and thus a systematic irradiance level difference throughout the day. Finally, panel age and dirt collection may cause asymmetry between existing and newly-installed panels. These factors are particularly relevant to residential installations where owners only purchase a portion of the panels upfront and plan on acquiring additional panels to increase the power output in the future.
Cell-Level Integrated Converters
At the sub-module cell level, the solar cells are closely spaced such that their external operating conditions are highly correlated and can be approximated as being nearly identical. Thus, the dominant source of asymmetry arises from the process variation between the cells in a sub-module string. Even though power tolerance can be limited down to ±3%, I-V mismatch can have higher tolerance when cells are sorted by maximum power. To study the effectiveness of a switched-capacitor DC-DC integrated converter at the cell level, a conservative maximum-power current variation of ±5% is assumed for the following description.
A first-order approximation for maximum power point tracking assumes that the cell output is step-wise linear when its output current is slightly perturbed around the maximum-power current. That is, if the current deviates from the maximum-power current by a small percentage ε, the output power is reduced from the maximum power by the same percentage.
I cell =(1−ε)· I mp (2)
P cell ≅(1−|ε|)· P max (3)
In the case where the cell maximum-power current varies by up to ±5%, an overall tracking efficiency above 95% is expected; that is, the sub-module string current can be set to the average maximum-power current so that it is always within 5% of each cell's individual maximum-power Current.
To increase tracking efficiency, finer conversion levels must be added to tune individual cells' current closer to their maximum-power current. Since cell-level variations are typically tightly constrained and voltage level is low, a relatively simple fully-integrated SC circuit can be used to provide a fractional step in both positive and negative directions. At the cell-level, simplicity is a benefit in minimizing integrated converter cost. The choice of the tuning step-size is illustrated in FIG. 2 assuming uniform distribution and maximum allowable maximum-power current variation of 8 around the norm. The entire space is quantized into 3 equally sized intervals of size 28/3 and the discrete tuning steps can be found as the center of each interval {I−2δ/3, 1, 1+2δ/3}.
Monte Carlo simulation results are shown in FIG. 3A . As expected from the approximation, the tracking efficiency with no integrated converter is slightly above 96%. With the introduction of integrated converters with discrete ±3.33% steps, an overall tracking efficiency greater than 98.33% is expected. The simulation results again agree with the intuitive model, and the tracking efficiency improves to above 98.7%. Potentially the greatest value in integrating converters at the cell-level lies in the fact that the added degrees of freedom allow the currently extensive and stringent binning process to be relaxed during manufacturing. Therefore, this invention makes it possible to lower the production cost of the solar panel itself and may open doors for a paradigm shift in the manufacturing process.
Consider the following example with the maximum allowable maximum-power current variation doubled from the previous case to ±10%. The simulation is repeated with a new optimal step-size of ±6.67% and the results are shown in FIG. 3B . The tracking efficiency of the relaxed binning process with integrated converters (97.5%) is shown to exceed that of the stringent binning process without integrated converters (96.2%). Furthermore, assuming a 98% conversion efficiency for the switched-capacitor circuit, the overall efficiency of the relaxed binning process with integrated converters becomes 95.6%. Thus, even when taking into account conversion efficiency, the cost effective switched-capacitor integrated converters approach presents minimal power loss compared to stringent binning process while offering a great opportunities in reducing the manufacturing cost of the solar panels.
Sub-Module String Level Integrated Converters
Referring now to FIGS. 4A and 4B , a group of solar cells are connected in series to form a sub-module string. In the exemplary embodiments of FIGS. 4A and 4B each of the sub-module strings are provided from six series connected solar cells. Those of ordinary skill in the art will appreciate that sub-module strings provided from fewer or more than six series connected solar cells may also be used. Three sub-module strings are used to provide the panel in FIG. 4A and three sub-module strings are used to provide the panel in FIG. 4B .
Comparing the conventional layout of the sub-module strings in FIG. 4A to the common centroid layout of the sub-module string in FIG. 4B illustrates the imbalance between sub-module strings caused by partial shading. That is, given small variations among each cell's maximum-power current, the overall maximum-power current of the sub-module string can be well-approximated as the arithmetic mean of the individual cells' maximum-power currents. Assuming the maximum-power current for the cells are i.i.d. with mean μ and variance σ 2 the overall maximum-power current of the sub-module string will roughly have a mean μ and a variance σ 2 /N, where N is the number of solar cells in the sub-module string. Therefore, for reasonably sized sub-module strings, the asymmetries can be attributed entirely to the external operating conditions.
Since the sub-module strings are closely spaced, their statistical variations must be correlated. In particular, external operating conditions such as temperature, dirt collection, aging, and orientation are for all intents and purposes identical because the strings occupy the same solar panel. Thus, the variability of the maximum-power current is expected to be constrained, which would limit the required tuning range of the SC integrated converter for a target tracking efficiency and thereby reduce cost. However, given the current sub-module string layout employed by the manufacturers, partial shading can cause substantial mismatch between sub-module strings. Such a situation is illustrated in FIG. 4A , where a panel with typical sub-module string layout is affected by partial shading, or a 1-D “hard” gradient, in the direction orthogonal to the string orientations.
Common centroid layout is effective in reducing gradient-induced mismatches. Utilizing such a technique in a solar panel layout would help substantially reduce the amount of mismatch caused by an imbalance in solar irradiance between the sub-module strings. Note that a custom layout requiring stringent parasitic control is not necessary; instead a simple PCB with the common centroid routing pattern is sufficient An example of such layout is shown in FIG. 4B . In the common centroid case, the power between the sub-module strings will remain symmetric with the same partial shading as before and will remain relatively balanced given other linear shading patterns as well.
A statistical evaluation method was adopted to simulate the effect of linear irradiance gradient. For each iteration in the simulation, a random linear shading pattern is generated. Each string's respective power is computed and the standard deviation of the string's maximum power is recorded.
As shown in FIG. 5 , the common centroid layout is very effective in compressing the standard deviation to below the power of a single solar cell. Furthermore, since the standard deviation is kept below the power of a single solar cell, the power variation between strings is expected to decrease inversely proportional to the number of power generating cells per string. To verify this hypothesis, additional simulations of 3 strings with 6 cells are performed to characterize the percentage power variation between the maximum and minimum power strings vs. the output power of the maximum power string.
As shown in FIG. 6 , while the normal string layout results in very high percentage variation in power between strings across all power levels, the common centroid layout significantly limits the percentage variation in power between strings at reasonable power levels.
The number of cells per string can be used as a design variable to limit variation between sub-module strings. By increasing the number of cells per string N, the expected percentage power variation should scale as ∝1/N. To provide design guidelines regarding the number of cells per string needed for a certain expected percentage power variation between strings, statistical simulations are repeated for a variety of sub-module string sizes.
The result is shown in FIG. 7 . While the expected power variation between strings for a normal sub-module string layout remains constant at approximately 65% as the number of cells per sub-module string varies, the expected power variation between strings for a common centroid layout decreases inverse proportional to the number of cells per sub-module string. Approximate 15 cells per sub-modules string can limit the expected percentage variation between strings to less than 10%. This results in 45 cells total and is comparable to current industry offerings. For example, the Mitsubishi PV-MFI70EB4 has 50 cells in series. In conclusion, this invention is effective in compressing the degree of variation among sub-modules string. Therefore, it enables the use of highly efficient converters with limited conversion range to perform MPPT at the sub-module string level.
Module Level Integrated Converters
By following a similar argument in the sub-module string section, process variation can be neglected at the even higher module level. For a large array of solar panels, there exist panels with relatively large spatial separations such that their maximum-power current variations become only weakly correlated. Consequently, at the module level, the SC DC-DC converters must have a wide tuning range to recover losses from the potentially large asymmetries in the maximum-power currents.
To optimally cover the possible range of maximum-power currents, the converter tuning range can again be broken up into uniformly-spaced discrete intervals where the centers of the intervals represent the relative conversion ratio. Some system design guidelines regarding choice of level granularity have been discussed in references such as Cooley, J. J.; Leeb, S. B.; “Per panel photovoltaic energy extraction with multilevel output DC-DC switched capacitor converters,” Applied Power Electronics Conference and Exposition (APEC), 2011 Twenty-Sixth Annual IEEE, vol., no., pp. 419-428, 6-11 Mar. 2011. Monte Carlo simulation assuming the worst-case uniformly distributed maximum-power currents was used to examine tracking efficiency tradeoffs at the module level. The result suggested good tracking efficiency improvement from 65% to 90% using a 5-level SC DC-DC converter in a 3-module system.
Maximum Power Point Tracking (MPPT)
A switched-capacitor integrated converter MPPT technique finds a conversion ratio such that a PV element is outputting a desired power given a desired output current I 0 . Ideally, the switched-capacitor integrated converter MPPT technique finds an optimal (or near optimal) conversion ratio such that the PV element is outputting a maximum (or close to maximum) power given the desired output current I 0 . In other words, the converter must find conversion ratio Qi to reduce (ideally, minimize) the difference between PV element's current Q i l 0 and the PV element's maximum-power current I mp,i , where I mp′i can be estimated by measuring the short-circuit current of the PV element as is known. Furthermore, it is noted in the above-mentioned reference that a perturb-and-observe step may be necessary for good accuracy following the initial I mp estimate. In a discrete conversion system, this typically requires two additional measurements (sometimes at most two additional measurements) of both current and voltage.
While the above control strategy is viable, it can be further simplified since there are only a small number of conversion levels available. Instead of using the maximum-power current estimate from short-circuit current measurement followed by a perturb-and-observe step, the local MPPT algorithm can simply loop through all the conversion levels to search for the maximum-power conversion ratio. This translates to only two additional observations in the 5-level converter discussed at the module level. At sub-module string and cell levels, only one additional observation is required. Furthermore, there is no longer a need to measure the output current I 0 if the brute-force search method is employed. Instead, the control algorithm only requires knowledge of the output voltage of the integrated converter in order to maximize energy extraction from the PV element.
Even more simplification can be performed at the sub-module cell level. As discussed in section II-A, the converters at the sub-module cell level are added mainly to reduce process variation induced mismatch. Since asymmetries caused by process variation are unlikely to change significantly over the lifetime of the solar panel, there is no need to run the optimization algorithm continuously during normal operation. The conversion ratio can be hard programmed at panel assembly time, or be self-calibrated on a regular basis.
Referring now to FIG. 7A , a Maximum Power Point Tracking (MPPT) process suitable for use with the MPPT controller shown in FIG. 13 , for example, is shown.
Module Level Converter Experimental Results
Overall Experimental Setup
An experimental prototype of the Marx Multilevel converter proposed in the above mentioned reference was constructed and characterized. Summaries of the circuit components and parameters for each of the implemented conversion ratios are shown in Table I.
TABLE I
EXPERIMENTAL PROTOTYPE PARAMETER SUMMARY
Parameter
Symbol
Value
Switched-capacitor
C
12.51LF
Switching Device
M
IRF8721
Panel Capacitor
CD.t
25JlF
Local Output Capacitor
Col
12.5JlF
Switching Frequency (Q -2)
fSW02
100
kHz
Switching Frequency (Q-3)
fsw.D3
88
kHz
I Switching Frequency (Q -4)
fsw.04
127
kHz
Panel I MP
PMP,
170
W
Panel I MP Voltage
VMP,
24.6
V
Panel I MP Current
Iup,
6.93
A
Panel I Series Resistance
Rsl
0.6350
Panel I Shunt Resistance
RD.1
540
Panel 2 MP
PUP?
85
W
Panel 2 MP Voltage
VUP?
24.6
V
Panel 2 MP Current
luP?
3.47
A
Panel 2 Series Resistance
RS2
1.270
Panel 2 Shunt Resistance
RD•2
108.10
FIG. 8 shows the connection diagram of the experimental setup consisting of two series connected modules and the constructed PV circuit models. In this experiment, Q=2 and Q=4 modules were constructed to perform MPPT on two unbalanced PV circuit models. Conversion efficiency was measured using HP34401A digital multimeters. Input and output voltages for each converter were measured at the PCB terminals. Current sense resistors with nominal resistance of lOm.ll were used to measure input and output currents. The precise values for each current sense resistor were measured separately to within 0.01 mΩ using current-mode and voltage mode digital multimeters simultaneously
Experimental Prototype Performance
The plots in FIG. 9 show measured efficiency data compared to simulated and calculated values. Peak conversion efficiency of 92.2% was measured and an optimized conversion efficiency of 95.2% is projected. The added loss in the conversion efficiency plot is due to standby power dissipation not included in simulation and calculation.
The switching frequencies for the experimental prototype were chosen based on the measured data. Since the most efficient switching frequency generally depends on conversion ratio, in order to maximize the overall system efficiency, the switching frequency showing the maximum conversion efficiency must be chosen for each conversion ratio.
Standby Power Dissipation
After constructing and characterizing the experimental prototype, several conversion efficiency optimizations are immediately clear. Several sources of power dissipation that can be optimized will be computed and reasonable values in an optimized prototype will be speculated. These will serve as design guidelines for future iterations of the switched-capacitor converter design.
The largest contributor to the discrepancy in efficiency between the simulated and the measured systems is the standby power dissipation. One significant portion of the standby power dissipation originates from biasing the zener diodes in the gate drive charge pump circuits shown in FIG. 10 . The biasing resistor sets the current through the zener diode and should be optimized to provide just sufficient bias current without dissipating excessive power. Thus, appropriate values for the zener bias resistors should be chosen based on the time-averaged voltage across them. The time-average voltage across the bias resistor is the time-averaged MOSFET source voltage minus the zener voltage. Therefore, the bias resistor value is related to both the associated MOSFET and the conversion ratio. Table II indicates the MOSFET source voltages normalized by the input voltage across possible conversion ratios.
TABLE II
MOSFET SOURCE VOLTAGES
NORMALIZED TO INPUT VOLTAGE
Recharge
Q = 0
Q = 1
Q = 2
Q = 2
Q = 2
MI
0
0
0
I
1
I
M2
0
0
0
0
0
0
M3
I
I
I
I
I
I
M4
0
0
0
I
I
2
M5
0
0
0
I
I
I
M6
I
I
I
2
2
2
M7
0
0
0
I
2
3
M8
0
0
0
I
I
2
M9
I
I
I
2
2
3
MI0
“”½
0
I
2
3
4
MIl
0
0
0
I
2
3
In the experimental system, the only MOSFETS that require charge-sustaining gate drives are M3, M6, M9 and M10. To compute the upper limit of the biasing resistor, the minimum zener bias current and the minimum input voltage must be considered. For instance, with V in,min =24V and I z,min =18 mA, the time-averaged bias voltage for the MOSFET M6 in the Q=2 operation is
〈
V
z
6
,
Q
2
〉
=
24
·
1
+
2
2
-
15
=
21
V
.
(
4
)
The maximum zener bias resistor value for the M6 in the Q=2 switching pattern is then
R
z
6
,
Q
2
≤
〈
V
z
6
,
Q
2
〉
I
z
,
min
(
5
)
=
1.17
k
Ω
.
(
6
)
The time-averaged power in the resistor can be calculated to be
R
R
6
,
Q
2
=
〈
V
z
6
,
Q
2
2
〉
R
z
6
,
Q
2
=
〈
V
z
6
,
Q
2
〉
2
+
(
0.707
·
Δ
V
M
6
,
Q
2
)
2
R
z
6
,
Q
2
(
8
)
=
21
2
+
(
0.707
·
12
)
2
1.17
·
10
3
(
9
)
=
440
mW
.
(
7
)
where a square wave of bias voltage and the maximum allowable bias resistance are assumed. In addition to the power dissipated in the resistor, the zener diode itself dissipates power. The zener power dissipation can be approximated as
P z,i ≈l z ·V z,i (10)
=18 mA·15V=270 mW. (11)
Since both sources of loss (i.e. time-averaged power in the resistor and power dissipated in the zener diode itself) depend heavily on the zener bias current, the zener diode bias should be minimized to reduce the standby power required for biasing. Note that this optimization is valid to the extent that the zener bias current is larger than the current demanded by the charge pump circuit.
A third source of standby power dissipation originates from charging and discharging the timing capacitor in the charge pump circuit. This loss can be calculated as:
P cp,timing =C cp ·V z,i 2 ·f cp . (12)
where the timing capacitor is assumed to fully charge to the zener voltage and fully discharged each switching cycle. Therefore, reducing the timing capacitance value may constitute a significant optimization. The charge pump switching frequency can remain unchanged by increasing the timing resistor by the same factor.
These un-optimized standby power dissipation sources are characterized and tabulated. Reasonable optimized values for the fully discrete implementation of the Marx experimental prototype are calculated as well. The optimized standby power dissipation numbers are assumed in the conversion efficiency data provided above. The results are summarized in Table III for the Q=2 module.
TABLE III
STANDBY POWER OPTIMIZATION
RESULTS FOR Q = 2 MODULE
Source
Un-Optimized
Optimized
Charge Pump Zener M3
432 mW
48 mW
Charge Pump Zener M6
710 mW
72 mW
Charge Pump Zener M9
710 mW
72 mW
Charge Pump Zener MI0
502 mW
60 mW
Charge Pump Timing Cap x 4
130 mW
26 mW
HV Level Shift x 11
158 mW
IOO mW
ICM7555 x 5
6 mW
6 mW
LM7812
158 mW
IOO mW
LM7805
6 mW
6 mW
Total
2.8 W
500 mW
The experiments demonstrate the value and approach to loss minimization for a particular MIC design. Different gate drive architectures may be employed in a practical switched-capacitor MIC integrated circuit. While the specific details of the appropriate optimizations will vary with the MIC topology, the possibilities and approach for developing a high efficiency converter are illustrated here.
Run-Time Zener Biasing Optimization
As shown above, the optimal zener bias resistance value depends on the conversion ratio, it should be chosen at run-time to minimize standby power. One approach could be to implement a switched set of fixed resistors for each gate drive, and the converter could choose the resistor based on the conversion ratio. One such scheme could be implemented using ground-referenced MOSFETs and TTL level control signals. This is illustrated in FIG. 11 .
However, the optimal Zener bias resistance value also depends on the input voltage. As the input voltage increase beyond the minimum value of 24V, excessive power dissipation is introduced in the passive biasing circuit. Thus, an even more efficient solution employs active current sources to provide the zener bias current. The circuit schematic using a basic bipolar current mirror is shown in FIG. 12 .
However, more advanced current mirror techniques, such as the Widlar and Wilson mirrors, can also be employed given sufficient headroom. In this case, the power dissipation in the biasing circuit is simply:
P z,i = V MOSFET,s,i ·I z,i . (13)
For instance, to minimize the standby power dissipation, a zener diode with a low bias current of 2 mA is selected. Then, the power dissipation of M6 zener biasing would be
P
z
,
6
=
24
·
1
+
2
2
·
0.002
=
72
mW
.
(
14
)
Run-Time Frequency Scaling
Based on Table I, the switching frequency yielding the highest conversion efficiency is dependent of the conversion ratio. Therefore, the switching frequency should also be selected at run-time to ensure the highest overall conversion efficiency is achieved. This selection may be based on a pre-determined set of optimal switching frequencies for a specific load current.
Grid-Tie Inverter Interface
The proposed centralized inverter consists of three components illustrated in block schematics in FIG. 13 . Unlike conventional string inverters and microinverters that close a single feedback loop on the current injected to the grid to control both maximum power point tracking and power delivery to the grid, the proposed architecture uses two separate controllers to achieve maximum power point tracking and energy balance.
The input current sink serves as the MPPT tracking control by demanding a current from the PV array that maximizes the product of the demanded current and the PV array voltage. Functionally, the input current sink could be implemented as a canonical cell converter such as a boost or a SEPIC converter. The input power from the PV array can then be monitored by measuring the PV array input voltage. An energy balance control loop can then be designed to use this information to control the power injected to the grid. That is, the input power can be fed forward to improve grid-tie inverter response time and controller stability.
Grid-Tie Inverter Stability
The stability of a grid-tie inverter can be derived by a small-signal equivalent circuit model shown in FIG. 14 , where the grid-tie inverter is modeled as a Norton equivalent current source and the utility grid is modeled as a Therein equivalent voltage source. Using the equivalent circuit model, the output current of the inverter can be solved by superposition to be
I
(
s
)
=
I
gti
(
s
)
·
Z
c
(
s
)
Z
c
(
s
)
+
Z
g
(
s
)
-
V
grid
(
s
)
Z
c
(
s
)
+
Z
g
(
s
)
=
(
I
gti
(
s
)
-
V
grid
(
s
)
Z
c
(
s
)
)
·
1
1
+
Z
g
(
s
)
Z
c
(
s
)
.
(
16
)
(
15
)
From the above equation, the stability criterion can be derived. Specifically, the impedance ratio Zg(s)/Ze(s) is required to satisfy the Nyquist criterion. This implies that the grid-tie inverters should be designed to have output impedance Ze(s) significantly higher than the grid impedance in order to operate with stability when connected to the grid. That is, the following condition should be satisfied.
Z
g
(
s
)
Z
c
(
s
)
<
1
(
17
)
Furthermore, the control strategy for the grid-tie inverter has strong effects on the inverter's output impedance. Thus, separating the controls into two separate loops simplifies the inverter output impedance derivation and provides additional insights for design. Below, a control strategy will be outlined and the output impedance will be derived.
Energy Balance Control
The power Pin flows into the grid-tie inverter via the input current sink and is delivered to the utility grid by controlling the magnitude of the output current. The energy buffer capacitor would store any energy difference between the input energy and the energy delivered to the grid.
A sampled-data approach is adopted where the input power Pin and the energy stored on the buffer capacitor e are sampled at twice the line frequency. Using the sampled data, the controller specifies the scale factor of the reference current waveform for the next cycle. Note that the reference current waveform is assumed to be a scaled version of the grid voltage for unity power factor operation. In addition, a fast inner current hysteresis loop is assumed to shape the current injected to the grid. The energy balance equation can then be written as:
e[n+ 1 ]=e[n]+P in ·T−∫ nT (n+1)T c[n]·v grid 2 ( t ) dt (18)
where e is the energy stored in the capacitor C at the n-th sampling instant, T is the sampling period of 1/(120 Hz), and Vgrid(t) is the voltage of the grid. For the following analysis, assume that the grid voltage has nominal amplitude of Vs.
Given ideal components, the grid-tie inverter can be controlled without any feedback. By selecting e=2Pin/Vsz, the integral term cancels the Pin T term exactly, so the energy stored on the buffer capacitor will be in steady-state. However, practically there are always errors in the computation of power due to losses and model deviation so the current amplitude control c will be implemented with a feedforward term plus a feedback term.
c
[
n
]
=
c
0
+
c
~
(
19
)
=
2
·
P
in
V
s
2
+
k
·
2
V
s
2
·
T
·
e
~
(
20
)
A model for computing the incremental output impedance is shown in FIG. 15 . This analysis was first presented for the nonzero input source impedance in a unity power factor converter.
In the grid-tie inverter case, the analysis can be applied in the “reverse” direction. Let vi represent a small voltage source perturbation used to probe the output impedance of the inverter as presented to the grid. This voltage can be expressed as a perturbation to the steady-state grid voltage Vgrid(t)=Ys·cos(wot) such that
v grid ( t )+ v i ( t )= V s ·cos(ω 0 t )·{1+ε·cos(ω 1 t )} (21)
where ω 0 is the line frequency, ω 1 <ω 0 and ε<<1. That is, v i corresponds to an additive perturbation in a frequency range near ω 0 . In order to solve for the output impedance, the corresponding perturbation in the input current needs to be solved. Assuming small enough ε and ω 1 , the integral term in (18) can first be approximated as
c
[
n
]
·
TV
s
2
2
+
c
[
n
]
·
ε
·
TV
s
2
·
cos
(
ω
1
T
·
(
n
+
1
2
)
)
.
(
22
)
And the difference equation can then be approximated as
e
[
n
+
1
]
≈
e
[
n
]
+
P
in
T
-
c
[
n
]
·
TV
s
2
2
-
c
[
n
]
·
ε
·
TV
s
2
·
cos
(
ω
1
T
·
(
n
+
1
2
)
)
.
(
23
)
Simplifying the expression further by cancelling the P in T term and the c 0 ·TV s 2 /2 term, and assuming the product of two small signal terms is negligible, the following difference equation can be written.
e
~
[
n
+
1
]
≈
e
~
[
n
]
·
(
1
-
k
)
-
c
[
n
]
·
ε
·
TV
s
2
·
cos
(
ω
1
T
·
(
n
+
1
2
)
)
(
24
)
Equivalently, the difference equation can be expressed in terms of the feedback term in the control variable using Equation (20).
c
~
[
n
+
1
]
2
k
≈
c
~
[
n
]
·
1
-
k
2
k
-
c
[
n
]
·
ε
·
cos
(
ω
1
T
·
(
n
+
1
2
)
)
(
25
)
Finally, the total current delivered to the grid from the converter output can be written as
I grid ( t )− i i ( t )= c[n ]·( v grid ( t )+ v i ( t )) (26)
≈ c 0 ·v grid ( t )+ {tilde over (c)} ( t )· v grid ( t )+ c 0 ·v i ( t ). (27)
where {tilde over (c)}(t) is the result of passing the discrete sequence {tilde over (c)}[n] through a zero-order hold. The incremental current due to the voltage perturbation can then be approximated as
i i ( t )≈ε· c 0 ·v grid ( t )·cos(ω 1 t )− {tilde over (c)} ( t )· v grid ( t ) (28)
≈−ε· c 0 ·v grid ( t )·cos(ω 1 t )·{1 +H (ω 1 )} (29)
where H(ω 1 ) is the response of the product of the transfer function in Equation (25) and a sampler at rate 1/T. Making the known approximations, the approximate expression for the incremental output impedance be solved in terms of Wt and re-expressed in terms of w by using substituting Wt=W−Wo.
Z
c
(
ω
)
=
-
1
c
0
·
1
1
+
sin
c
(
(
ω
-
ω
0
)
T
2
)
-
2
k
ⅇ
j
(
w
-
w
0
)
T
(
1
-
k
)
(
30
)
FIG. 16 shows the magnitude and phase of the grid-tie inverter's incremental output impedance. Note that the expression in Equation (2) is only valid for frequencies near 60 Hz, specifically, |ω−ω 0 |<π/T. Due to the sample and hold operations, perturbations with frequency content outside of this range will alias into this range. As shown in the figure, the incremental output impedance looks real and positive with value V s 2 /(2P in ) at 60 Hz. However, the magnitude of the incremental output impedance decreases as the perturbation frequency deviates from 60 Hz. In particular, the decrease in magnitude of the incremental output impedance is more significant for larger values of the feedback gain parameter k. Note that the phase of the incremental output impedance quickly changes 1800 as the perturbation frequency deviates from 60 Hz as well. Therefore, referring back to the stability criterion derived in Equation (17), larger feedback gain values make the grid-tie inverter more susceptible to stability problems due to decreasing impedance magnitude.
The benefit of the novel grid-tie inverter interface invention now becomes evident. By decoupling the MPPT tracking and the energy balance control loops, the system can potentially operate more stably by relying more heavily on the feedforward term than the feedback term. In addition, since the MPPT tracking is controlled by an input current sink, the change in power from the PV array can be accurately monitored by measuring the PV array voltage only. Even if the feedback loop is not fast enough to track input power transients, the feedforward path can force a resample mid-cycle (at the price of non-unity power factor for one cycle) to prevent the energy buffer capacitor voltage from running out of range. The forced resample may be triggered by passing the PV array voltage through a high-pass filter and level detectors to check for sudden large steps in input power. Note that the frequency of occurrence of such event is expected to be low.
Bus Capacitor Utilization
A DC-to-AC converter needs an energy buffer stage to store the instantaneous power difference between the input and the output ports. Such an energy buffer is typically implemented with a single large capacitor. As the system reaches periodic steady state, the instantaneous power difference manifests itself in a ripple voltage on the capacitor at twice the line frequency. The exact expression for the magnitude of the voltage ripple can be derived. Assume the grid-tie is in period steady state so that
v
in
·
i
in
=
1
2
·
v
grid
·
i
grid
.
(
31
)
where v in and i in are DC values, and v grid and i grid are AC amplitudes. The factor of ½ arises from the RMS conversion. The instantaneous power on the buffer capacitor can be written as
P cap =P in −P grid (32)
= P in −2 ·P in ·cos 2 (ω 0 t ) (33)
=− P in ·cos(2ω 0 t ). (34)
If the power is integrated over the positive half capacitor ripple cycle, or a quarter of the line cycle, the peak to peak energy change in the storage capacitor can be calculated as
Δ
E
cap
=
∫
positive
half
ripple
cycle
P
in
·
cos
(
2
ω
0
t
)
ⅆ
t
=
P
in
ω
0
(
35
)
Finally, the peak-to-peak energy change can be translated into peak-to-peak voltage ripple on the energy buffer capacitor.
Δ
E
cap
=
1
2
·
C
·
(
V
c
+
1
2
Δ
V
r
,
pp
)
2
-
1
2
·
C
·
(
V
c
-
1
2
ΔV
r
,
pp
)
2
(
36
)
Combining (35) and (36) gives the expression for the voltage ripple on the energy buffer capacitor.
Δ
V
r
,
pp
=
P
in
ω
0
·
C
·
V
c
(
37
)
Equation 37 provides clear guidelines for grid-tie inverter bus capacitor sizing. For instance, given a 1 kW power system with nominal bus capacitor voltage of V c =400V and maximum allowable peak-to-peak voltage ripple ΔV r,pp =20V, the energy buffer capacitor must be at least 332 μF.
Now consider the energy utilization of the capacitor in this case. The capacitor stores a maximum of 27.9 J but only 2.65 J is used to buffer the instantaneous power difference between the input and output ports. Thus, the energy utilization of a single bus capacitor implementation allowing 5% ripple voltage is:
Δ
E
cap
E
cap
,
max
=
9.5
%
.
(
38
)
The capacitor shift topologies are known to achieve higher energy utilization and lower voltage ripple. Applying such a topology to the energy buffer capacitor would lead to more effective capacitor utilization and smaller capacitor volume for the same allowable voltage ripple.
As an illustration, consider the capacitor shift topology in FIG. 17 , where only one switch can re turned at any given time. For simplicity consider the base example with only C 0 , C 1 , S 0 , and S 1 are present. Assume unit capacitance, arbitrary initial conditions and that the bus experiences discharging by a unit current source for 1 second then charging by a unit current for 1 second. Furthermore, assume that switch S 0 , is turned on the moment discharge cycle begins.
In order to minimize the ripple seen at the top of the bus, it must be true that after C 0 is discharged through S 0 for some time, S 0 will turn off and S 1 will turn on to add the initial voltage of C 1 back onto the bus. Thus, the initial condition for capacitor C 1 must be a positive and equal to the initial voltage drop in C o . After S 1 turns on, the bus voltage now decreases twice as fast as before.
The optimal case is when the two sub-cycles exhibit the same drop in bus voltage, i.e. S o turns off after ⅔ seconds. Thus, the optimum ripple magnitude now becomes ⅔ of that of the single bus capacitor case.
During the charge cycle, the switching sequence is the mirror sequence of the discharge cycle. That is, the capacitors will end up same charge they started with before the discharge cycle.
This method can be extended to the energy buffer bus capacitor, where the charge and discharge current waveforms are sinusoidal.
The corresponding waveforms are shown in FIG. 18 . The two waveforms show the same reduction in ripple magnitude but with different timing for the switches. The switch timing can be solved by taking the inverse of the sinusoidal function at the corresponding ripple magnitudes.
The initial condition for C 1 only depend on the ripple size, which leads to very low voltage ratings. On the other hand, the initial condition for C o cannot be determined by using the ripple size alone. In the case of an inverter energy buffer, the initial voltage on C o instead depends upon the nominal bus voltage, which requires high voltage rating.
Consider the previous example with maximum allowable peak-to-peak voltage ripple reduced by 33%. Assume electrolytic capacitors are used and their volume scales with
Vol∝ C·V rating 1.5 . (39)
In the conventional case, the energy buffer capacitance would need to increase by 50%, which translates 50% more volume. However, in the switched-capacitor implementation, even though the same capacitance is added, the required voltage rating is only 13.3V. Therefore, the total increase in capacitor volume from the estimate in (39) is less than 0.6%.
The theory can be generalized to any number of switches and capacitors. Using N equally sized capacitors in the switching configuration, the ripple size is reduced to
Δ
V
r
,
pp
=
2
N
+
1
·
(
P
in
ω
0
·
C
·
V
c
)
.
(
40
)
Furthermore, each capacitor in the array must be charged to some initial voltage before the discharging cycles begin:
V
i
,
max
=
{
V
bus
+
1
2
·
(
P
in
ω
0
·
C
·
V
c
)
,
i
=
0
i
+
1
N
+
1
·
p
in
ω
0
·
C
·
V
c
,
1
≤
i
≤
N
-
1
(
41
)
In the proposed architecture, all of the values in the above three equations are readily measured. Thus, the capacitor voltages can be tightly monitored and robustly controlled. Note that evaluating V i,max as shown above using the maximum input power from the PV array would yield the voltage ratings for the capacitors.
To illustrate the potential application of this switched-bus-capacitor approach for a grid-tie inverter, consider the results of a basic control algorithm implemented in a SPICE simulation.
The circuit block diagram and the controller overview are shown in FIG. 19 . The switched-bus-capacitor energy storage is implemented with just two capacitors for illustration purposes. The system is designed to maintain a bus voltage of 250V and deliver a maximum of 500 W to the grid. The preliminary control strategy developed here pre-computes the optimal cycle timings to switch in C 1 while maintaining the voltage V C,1 within the bounds calculated from the above three equations. That is, whenever the voltage V C,1 is about to exceed the calculated bounds, Q c,o is switched on so C o absorbs the rest of the charge or discharge current alone. The voltage on C o is then regulated by the energy balance control loop.
Note that in a sampled system, the worst-case behavior occurs if a large transient occurs directly after sampling has taken place. Thus, this is the case chosen for the simulation. However, by forcing the system to resample, the inverter output current settles to the final value almost immediately as shown in FIG. 20 . Furthermore, the bus capacitor control is shown to keep the voltage V c,1 within the calculated bounds in real-time.
Referring now to FIG. 21 , an exemplary SC energy buffer (preferably a low-frequency SC energy buffer) is coupled between an interfacing converter (preferable a high frequency interfacing converter) and a DC/DC converter (preferably a high-frequency SC energy buffer). It should be appreciated that the DC/DC converter is optional. In this exemplary embodiment, SC energy buffer is shown to include a single so-called “backbone” bank of capacitors and a single so-called “supporting” bank of capacitors. It should however, be appreciated that one or more banks of backbone and supporting capacitors may be used. Each of the backbone and supporting banks of capacitors includes one or more capacitors. The configuration is described herein as y-z, where y is the number of capacitors in the backbone bank and z is the number of capacitors in the supporting bank.
The backbone capacitor bank contains capacitors that withstand large voltage variations during the ripple cycle, where the voltage variations are typically much greater than the prescribed peak-to-peak ripple allowance. In order to bring the bus voltage ripple within bound, the supporting capacitor bank is switched so that the voltages of the supporting capacitors are either added to or subtracted from the voltage of the backbone capacitor bank. The switching pattern is defined such that the resulting bus voltage satisfies the ripple specification. The supporting capacitors have to withstand a much smaller voltage variation during the ripple cycle. Specifically, in this two-bank energy buffer architecture, the voltage variations on the supporting capacitors are limited to one-half the specified peak-to-peak bus ripple magnitude if the supporting capacitors and backbone capacitors are equally sized.
Using this technique with a peak-to-peak ripple ratio of 10%, energy utilization can be improved to >70% with one backbone capacitor and >80% with three backbone capacitors. Moreover, this technique enables the use of capacitors with smaller capacitance and lower voltage ratings, thereby making it possible to replace limited-life electrolytic capacitors with ceramic or film capacitors. Practical uses of this technique require control schemes that can produce acceptable transient responses to time-varying power levels. Accordingly, described herein below are different control schemes and descriptions of undesirable behavior under certain operating conditions. Also, described herein is a two-step control scheme which considers tradeoffs between circuit topology and control. Also described herein are factors to consider in topology selection and switching configurations as well as control strategy requirements and tradeoffs.
Different control schemes have been proposed for the SC energy buffer shown in FIG. 21 . Two approaches referred to as “Bus-Voltage Monitoring, Finite State Machine Control” and “Supporting Capacitor Monitoring, Timing Interval Control” are described below.
In the Bus-Voltage Monitoring, Finite State Machine Control scheme for the case of an SC energy buffer inside a PFC utility interface, the controller directly monitors the bus voltage and triggers finite-state-machine state transitions when the bus voltage is about to exceed pre-defined bounds. The switching pattern associated with each state is defined so that an increase in state number would boost the bus voltage up by Δv r,pp when the bus voltage dips below the lower trigger threshold, and a decrease in state number would drop the bus voltage down by ΔV r,pp when the bus voltage rises above the upper trigger threshold.
Because the supporting capacitor voltages are not individually monitored, state transitions do not guarantee the desired boost or drop on the bus voltage. Also, the state machine is unaware of the power level and is not reset or “re-centered” between ripple cycles, so power transients may cause the state to saturate at either the state associated with the lowest or the highest apparent energy. During this state saturation, the SC energy buffer no longer has any available state to contain the ripple in the saturation direction. Finally, because the controller attempts to maintain the bus voltage within constant DC boundaries at all times, a transient response to a new steady-state power level can lead to extreme bus voltage transients as the controller will attempt to maintain the DC boundaries until it is driven into state saturation.
To investigate such undesirable behaviors, a SPICE simulation is performed using LTSpice from Linear Technology. An LT1249 active power factor controller is selected for the simulation because the model is readily available in the bundled component library. The simulated test bench circuit is derived from the typical application example in available datasheets (e.g. a Linear Technology, “LT1249—Power Factor Controller,” Datasheet) with the output filter capacitor replaced by the 2-6 SC energy buffer described herein. In addition, the simulation model also incorporates a controller implemented with a 24-state finite state machine and an “artificial feedback voltage” as described in Minjie Chen; Afridi, K. K.; Perreault, D. J.; “Stacked switched capacitor energy buffer architecture,” Applied Power Electronics Conference and Exposition ( APEC ), 2012 Twenty - Seventh Annual IEEE , vol., no., pp. 1404-1413, 5-9 Feb. 2012. The design specifications include a nominal output voltage of 320V and a 20% peak-to-peak ripple ratio.
Referring now to FIGS. 22A, 22B , simulation results are shown in the form of plots of bus voltage ( FIG. 22A ) and FSM state ( FIG. 22B ) vs. time. FIG. 22A illustrates a transient bus voltage response of a 2-6 SC energy buffer in a PFC due to a 30% load power step. As seen in FIG. 22A , the bus voltage exhibits unacceptable over- and undershoots when the state machine state saturates at states 1 and 24 in response to 30% load power level transients. It should be noted that the artificial feedback voltage does not faithfully reproduce the over- and undervoltage conditions. The extreme overshoots from the shortcomings of the controller are amplified by two additional factors. The capacitances of the capacitors in the energy buffer are greatly reduced under the assumption of proper ripple reduction. Moreover, the capacitors are linked in series, which further diminishes the effective capacitance seen on the bus.
In the Supporting Capacitor Monitoring, Timing Interval Control scheme, a similar control problem to that mentioned above (in connection with the bus-voltage monitoring, finite state machine control scheme) can be illustrated considering FIG. 21 in its inverter configuration. In this case, the individual supporting capacitor voltages are monitored while giving up the task of controlling the backbone capacitor voltage to the energy-balance controller of the inverter. The control logic pre-computes the charge and discharge intervals for each supporting capacitor relative on the phase of the ripple cycle and enables these intervals when the capacitor voltages are within their reference minima and maxima.
The reference voltages scale linearly with power level and the ripple is reduced by a fixed ratio. Therefore, the resulting bus voltage behavior is very similar to that of a single capacitor implementation—the backbone capacitor experiences the natural transient and settling behaviors from the energy-balance controller, and the supporting capacitors are used to keep the ripple voltage within the prescribed limits.
However, this controller does not necessarily make the most efficient use of the supporting capacitor bank—all capacitors in the supporting bank are used regardless of power level. As a result, the supporting capacitor voltage references must be adjusted significantly in response to power variations. Since the voltage on capacitors cannot change instantaneously, the supporting capacitors will need time to be charged or discharged to the new reference levels. This introduces a few cycles where the supporting capacitors experience large imbalance in their charge and discharge times. In the extreme case, the supporting capacitors may not be used in either the charge or the discharge cycle at all, thus exposing the bus to the full-swing ripple from the backbone capacitor with reduced capacitance during the corresponding half cycle.
A SPICE simulation is again used to demonstrate the potential problems with this control strategy. A simulated test bench circuit was implemented using a feedforward energy-balance controlled solar inverter (e.g. as described herein above) along with a 1-8 SC energy buffer. The nine supporting capacitors are monitored and managed by the controller with pre-computed switch timings discussed above, and the backbone capacitor is controlled by the feedforward energy-balance controller of the solar inverter. The design specifications include a nominal output voltage of 250V and a 10% peak-to-peak ripple at maximum power.
Referring now to FIGS. 23A, 23B , simulation results (plots of buffer voltage ( FIG. 23A ) and support capacitor voltages ( FIG. 23B ) vs. time) are shown which illustrate a transient bus voltage response of a 1-8 SC energy buffer in a solar inverter due to a 30% input power step. As shown in FIGS. 23A, 23B , the bus voltage experiences an unacceptable undershoot when the supporting capacitor voltages references are dramatically increased in response to 30% power level transients. FIG. 23B shows the nonparticipation of the supporting capacitors during their discharge half-cycles, resulting in the lack of buffering during the discharge half cycle. The energy buffer uses the unipolar switching configuration and is controlled by the supporting capacitor monitor, timing interval controller. The discharge is disabled in order to charge the supporting capacitors up to the new reference values, exposing the full-swing backbone capacitor ripple.
There are many tradeoffs and design considerations to be considered in designing an SC energy buffer. One basis for making these tradeoffs is described below. In principle, energy utilization can be increased arbitrarily at the expense of switching frequency and buffer complexity. Desirable transient performance implies control requirements that also impact SC buffer design. Such tradeoffs are discussed below in the context of two general SC buffer architectures, unipolar and bipolar switching configurations shown in FIGS. 24A, 24B .
FIG. 24A is block diagram of a 1-z architecture of an SC energy buffer implemented with ground-referenced switches only for unipolar switching configuration while FIG. 24B is a block diagram of a 1-z architecture of an SC energy buffer implemented with four additional switches (as compared with the FIG. 24A implementation), to achieve bipolar switching configuration.
A first consideration in designing the energy buffer is energy utilization when the design goal is to reduce the overall amount of physical capacitance in the system. Equation (1) summarizes the energy utilization for a non-switching, single capacitance buffer. The energy utilization equation can be generalized for the SC case shown in FIG. 21 by taking the sum of ΔE, the change in energy stored, divided by the sum of E max , the maximum energy stored, of all the capacitors in the energy buffer. This is shown in Equation (42).
E
util
=
∑
j
=
1
y
Δ
E
backbone
(
j
)
+
∑
i
=
1
z
Δ
E
support
(
i
)
∑
j
=
1
y
E
max
,
backbone
(
j
)
+
∑
i
=
1
z
E
max
,
support
(
i
)
(
42
)
The variables in Equation (42) depend upon not only the nominal bus voltage, the specified ripple ratio and the selected capacitor size, but also the switching configuration. Thus, the cases shown in FIG. 24A, 24B illustrate a tradeoff between topology and switching complexity versus capacitor utilization. Note that FIGS. 24A, 24B illustrate two embodiment having a single backbone capacitor, i.e., y=1 in each embodiment, although more backbone capacitors could be employed with arbitrary y.
Capacitor configurations are next described in conjunction with FIGS. 25A-25C which illustrate the energy utilization of an SC energy buffer with bipolar switching configuration versus different numbers of backbone and supporting capacitors for three different ripple ratios (10%, 5% and 2% ripple ratios).
FIG. 25A is a plot of overall energy utilization (in percent) of an SC energy buffer with bipolar switching configuration versus different numbers of backbone and supporting capacitors for a 10% peak-to-peak ripple.
FIG. 25B is a plot of overall energy utilization (in percent) of an SC energy buffer with bipolar switching configuration versus different numbers of backbone and supporting capacitors for a 5% peak-to-peak ripple.
FIG. 25C is a plot of overall energy utilization (in percent) of an SC energy buffer with bipolar switching configuration versus different numbers of backbone and supporting capacitors for a 2% peak-to-peak ripple.
At least Two conclusions can be drawn from the plots of FIGS. 25A-25C . First, for each ripple ratio and number of backbone capacitors used, there exists an optimal number of supporting capacitor which maximizes the energy utilization of the overall energy buffer. Secondly, the energy utilization can be improved with diminishing return by introducing more backbone capacitors.
In practical circuits, however, the number of backbone capacitors cannot be increased indefinitely. The switching frequency of the SC energy buffer is directly proportional to the number of capacitors in the energy buffer. In particular, the switching frequency can be approximated as
f sw ≈2 f grid ·p·y ·( z+ 1), (43)
where p=2 for unipolar switching schemes and p=4 for bipolar switching schemes.
In view of the above, it should be clear to one of ordinary skill in the art, that increasing the number of capacitors would unavoidably increase the incurred switching loss. Also, excessive number of capacitors would cause the SC buffer switching frequency to approach that of the PFC or inverter controllers, consequently causing undesirable interactions between the two control loops.
In an attempt to ensure time-scale separation between the low-frequency energy buffer control and high-frequency PFC or inverter control, the number of capacitors should be limited. When designing a switching converter, the switching frequency is expected to be high with respect to the natural frequency of the energy storage elements. This extends to the case of a SC energy buffer. While any specific case requires a control loop and stability analysis, a similar rule-of-thumb to keeping the natural time constant in the canonical models long compared to the switching period, e.g. 10 times the switching period, is to have the SC buffer switching at below 1/10 the frequency of the interfacing switching converter. As illustrated in FIG. 21 , high-frequency switching converters can be found on either side of the SC energy buffer.
For example, assuming the switching frequency of the high-frequency loop is on the order of a hundred kilohertz, average switching frequency of the energy buffer control might be constrained to be less than approximately ten kilohertz. In other words, the relationship in Equation (4) must hold.
p
·
y
·
(
z
+
1
)
≤
10
kHz
2
f
grid
(
44
)
This establishes an upper bound on the number of capacitors that can be incorporated in these SC energy buffers.
Referring again to FIGS. 25A-25C , the unfeasible combinations of capacitor configurations are greyed out. As shown, the achievable improvement in energy utilization is limited, albeit still significant, as this becomes a constrained optimization problem. For peak-to-peak ripple ratios of 2%, 5%, and 10%, the optimal achievable energy utilizations are realized with only one or two backbone capacitors.
In a SC energy buffer, the bus voltage is no longer an accurate measure of the energy stored in the energy buffer. Therefore, when integrating with conventional power-factor correction controllers or energy-balance inverter controllers, the bus voltage cannot be directly used as the feedback voltage. Some embodiments, for example, use an artificial feedback voltage to ensure compatibility with existing hardware. However, such an artificial feedback voltage is not guaranteed to be sinusoidal and may not reliably detect under- and over-voltage conditions as shown previously.
By implementing the backbone capacitor bank with only one capacitor, a voltage feedback signal is available at the single backbone capacitor for interfacing with conventional power-factor correction controllers or energy-balance inverter controllers. Because there is a single path in the backbone capacitor bank through which the energy buffering current must flow, the single backbone capacitor voltage can be treated as an AC-scaled version of the single electrolytic capacitor voltage in traditional energy buffers.
Energy utilization is still high with a single backbone capacitor. Specifically, in the case of 10% peak-to-peak ripple ratio, using a single backbone capacitor reduces the achievable energy utilization from 77.9% to 71.2%, still a sizable improvement from 18.1%. In the cases of 5% and 2% peak-to-peak ripple ratios, the optimal energy utilizations remain unchanged. Also, this simplification enables the exclusive use of ground-referenced switches in unipolar switching configurations.
Switching Topology Tradeoffs are next described. In view of the above, the 1-z architecture shown in FIGS. 24A, 24B is considered with N=z+1 defined as the total number of capacitors in the SC energy buffer. The backbone capacitor is denoted as C 0 , and the supporting capacitors are denoted as C 1 through C N-1 . Two types of switching configurations can be explored: unipolar and bipolar.
In unipolar switching, supporting capacitor voltages are added to the backbone capacitor voltage when it is too low, but are never subtracted. With equally sized capacitors, the resulting peak-to-peak bus voltage ripple with respect to the total number of capacitors is
Δ
V
r
,
pp
,
unipolar
=
2
N
+
1
·
(
P
ω
0
·
C
·
V
C
)
,
(
45
)
in which:
P is the power level,
ω 0 is the angular frequency of the grid,
C is the capacitance of all capacitors in the SC energy buffer; and
V C is the nominal voltage of the grid.
If the backbone capacitor voltage is regulated by energy balance control, i.e., to achieve constant mean squared voltage, using the unipolar switching configuration will result in a variable mean bus voltage. Specifically, the mean bus voltage will increase with increasing power level, but will always be above the regulated mean voltage of the backbone capacitor. For this reason, the unipolar switching configuration is unsuitable for PFC applications with constant output voltage requirements. However, it is compatible with solar inverters where the bus voltage must remain sufficiently high in order to maintain control of the grid. In addition, because the mean bus voltage is positively correlated to the power level, it ensures fast response time in hysteresis current controlled inverters when the output current amplitude is increased. Finally, the one-sided switching configuration also has the added benefit of being able to utilize ground-referenced switches only. By rearranging the supporting capacitor bank and the backbone capacitor as shown in FIG. 24A , the unipolar SC energy buffer avoids high-side gate drives.
In the bipolar switching configuration, four additional switches are added in order to invert the polarity of the supporting capacitor voltages during parts of the ripple cycle. This enables ripple reduction with a constant mean bus voltage. Supporting capacitor voltages are added to the backbone capacitor voltage when it is too low and are subtracted from the backbone capacitor voltage when it is too high. As such, the bipolar switching configuration is compatible with power-factor correction applications without an additional de-dc converter at the output. Moreover, the bipolar switching configuration uses the supporting capacitors more efficiently; it achieves a peak-to-peak voltage ripple of
Δ
V
r
,
pp
,
bipolar
=
1
N
·
(
P
ω
0
·
C
·
V
C
)
,
(
46
)
approximately twice as effective, in terms of ripple reduction capability versus number of capacitor added, as the unipolar switching configuration. The ripple advantage requires four extra switches and high-side gate drives, which contribute to additional switching losses.
The steady-state maximum supporting capacitor voltages under maximum power rating for both switching configurations are outlined here to supplement energy utilization calculations and to facilitate capacitor selections.
V
max
,
unipolar
(
i
)
=
i
+
1
N
+
1
·
P
max
ω
0
·
C
·
V
C
(
47
)
V
max
,
bipolar
(
i
)
=
i
+
1
2
N
·
P
max
ω
0
·
C
·
V
C
(
48
)
for i={1, 2, . . . , N−1}. For the backbone capacitor, the maximum capacitor voltage is the same for both switching configurations and can be calculated as
V
max
(
0
)
=
V
C
+
1
2
·
P
max
ω
0
·
C
·
V
C
.
(
49
)
Below, control strategies (including a two-step control strategy) for both unipolar and bipolar switching configurations are presented.
A controller capable of handling power level transients must not prescribe strict DC voltage boundaries constraints on the bus voltage. Instead it should allow the DC level of the bus voltage to undergo natural settling while maintaining the AC ripple magnitude within specification around the DC level. This enables the controller to evenly distribute the charge buffering to the supporting capacitors instead of leaving the terminal-state capacitors to absorb an unusual large amount of leftover charges. Also, the controller must effectively reset its state from ripple cycle to ripple cycle in order to guarantee the availability of reserve buffering states in the event of power transients. Finally, the controller must intelligently manage the supporting capacitors so they can remain effective in reducing the ripple magnitude at all time. This translates to maintaining the reference voltage levels of the supporting capacitors relatively constant regardless of power level.
These requirements can be satisfied by adopting a two-step control strategy: capacitor participation optimization and switch timing determination. The controller first determines the optimal number of capacitors to use in buffering the bus voltage, and then compute the switch timings for the allocated supporting capacitors to maximally reduce the bus voltage ripple. In a 1-z SC energy buffer configuration, the single backbone capacitor voltage is used as the feedback node to either a PFC or an inverter controller. Thus, the SC energy buffer controller discussed here passes the regulation of the backbone capacitor voltage to an external interfacing controller.
Two design examples are described to better illustrate the operation and the effectiveness of the proposed control strategy. The specification for the illustrative design examples is a 500 W inverter with a 250V nominal bus voltage and a 10% peak-to-peak ripple ratio. For maximum energy utilization, a 1-8 SC configuration is chosen for the unipolar switching scheme. For the bipolar switching scheme, a 1-4 SC configuration is chosen for comparable switching complexity and ripple reduction power.
In order to improve, or ideally optimize, supporting capacitor participation, the controller samples the current power level and calculates a number of capacitors required to keep the voltage ripple within the specification. Preferably, the controller samples the current power level and calculates the minimum number of capacitors required to keep the voltage ripple within the specification. The sampling frequency is twice the line frequency for the unipolar switching configuration and four times the line frequency for the bipolar switching configuration.
Referring now to FIGS. 26A, 26B , sampling points with respect to the ripple cycle are illustrated. FIG. 26A is a plot of sampling points and control variables, v c (l) and v d (i), in relation to the ripple cycle and the control ramps for a unipolar switching configuration and FIG. 26B is a plot of sampling points and control variables, v c (i) and v d (i), in relation to the ripple cycle and the control ramps for a bipolar switching configuration.
Note that the minimum required number should have a lower bound at 1 because the backbone capacitor is always used, and can be derived by inverting the ripple magnitude Equations (45) and (46) for the two different switching topologies. Equation (50) shows the solution for the unipolar switching configuration and Equation (51) shows the solution for the bipolar switching configuration. Note that P[n] is the sampled power level during the current ripple cycle.
N
unipolar
[
n
]
=
max
(
ceil
(
2
P
[
n
]
ω
0
·
C
·
V
C
·
Δ
V
r
,
pp
-
1
)
,
1
)
(
50
)
N
bipolar
[
n
]
=
max
(
ceil
(
P
[
n
]
ω
0
·
C
·
V
C
·
Δ
V
r
,
pp
)
,
1
)
(
51
)
One goal of this technique is to have a sufficient number of capacitors in reserve, ready to kick in during a sudden power level increase. By only using the minimum required number of capacitors, the controller ensures that there is a sufficient number of capacitors in reserve, ready to kick in during a sudden power level increase. In addition, relatively constant energy storage in the supporting capacitors is maintained over a wide range of power levels. Consequently, the system is able to respond to large power transients by adjusting the number of capacitors used, rather than drastically changing the energy stored on all the supporting capacitors.
Referring now to FIGS. 27A, 27B , these figures illustrate the supporting capacitor voltages ( FIG. 27B ) and the expected ripple size ( FIG. 27A ) across all possible power levels in a 1-8 unipolar SC energy buffer design such as that described herein above. The number of switching events is reduced as the power level decreases, which improves the overall system efficiency.
Given the number of capacitors to use, the controller proceeds to compute the switch timings for the capacitors based upon a current (or substantially current) power level. That is, the charge and discharge cycle durations are adjusted for each supporting capacitor based upon the current sample of its voltage and its respective reference values.
Since the charging and discharging of the capacitors by the double-line frequency energy flow are inherently nonlinear with respect to time, a nonlinear element may be inserted into the control loop to enable the use of simple linear function in the rest of the controller. In general, such a nonlinear element takes form of a control ramp upon which the switching event is triggered. For the unipolar switching configuration, the control ramp is a double-line frequency sine wave phase-locked to the grid. In addition, the unipolar control ramp is assumed to be normalized with unit peak-to-peak amplitude and ramps from 0V to 1V.
For a bipolar switching configuration, the ripple cycle can be further broken up into two sub-cycles. There is the additive sub-cycle where the supporting capacitor voltages are added to the bus voltage, and the subtractive sub-cycle where the supporting capacitor voltages are subtracted from the bus voltage. Thus, the same cycle duration computation needs to be performed twice as often as in the unipolar case. The control ramp function for the bipolar switching configuration then must be periodic at four times the line frequency. Specifically, the bipolar control ramp is a rectified and inverted version of the unipolar control ramp and ramps from 0V to 0.5V. The two control ramp signals in relation to their respective control voltages and sampling points are shown in FIG. 26 .
Because the control ramps are assumed to be normalized, the control equations will also be defined in a power-independent fashion. All sampled values are normalized to the full-swing ripple magnitude on the backbone capacitor. The normalizing function is defined as
v
_
[
n
]
=
v
[
n
]
P
[
n
]
/
(
ω
0
·
C
·
V
C
)
,
(
52
)
In which v[n] is the sampled supporting capacitor voltage.
Based on the normalized sampled supporting capacitor voltages, the allowable discharge and charge durations for each capacitor are calculated from (53) and (54),
disch
(
i
)
=
max
(
min
(
v
_
i
[
n
]
-
i
D
x
[
n
]
,
1
D
x
[
n
]
)
,
k
D
x
[
n
]
)
(
53
)
charg
(
i
)
=
max
(
min
(
-
v
_
i
[
n
]
+
i
+
2
D
x
[
n
]
,
1
D
x
[
n
]
)
,
k
D
x
[
n
]
)
(
54
)
where i={1, 2, . . . , N−1} denotes the supporting capacitor index, 1/D x [n] is the normalized step in voltage between the supporting capacitors, and kε[0, 1) determines the minimum duration. The variable x in D x [n] denotes the switching configuration. The discrete step size definitions differ in the two switching configurations and are shown in (55) and (56).
1
D
unipolar
[
n
]
=
1
N
unipolar
[
n
]
+
1
(
55
)
1
D
bipolar
[
n
]
=
1
2
N
bipolar
[
n
]
(
56
)
The minimum duration defined by k determines the tradeoff between transient ripple size and settling time. If k is very close to zero, the controller may allow the capacitor voltages to reach their new reference values quicker by imposing a large imbalance between their charge and discharge cycles. However, larger imbalances between the charge and discharge cycles increase exposure of the bus voltage to the ripples of the backbone capacitor, resulting in larger transient ripple. If k is very close to one, the controller will maintain ripple buffer throughout more of the ripple cycle. But the limited imbalance between the charge and discharge cycles results in longer settling times. Note that by managing the capacitor participation based on power level, the reference voltages for the supporting capacitors are kept fairly constant. Therefore, k can be set very close to one for adequate buffering without the risk of unreasonably long settling times.
Having computed the allowable charge and discharge durations for each supporting capacitor, the actual control voltages can be calculated by a cumulative sum. More specifically, the individual charge and discharge control trigger levels are
v
d
(
i
)
=
∑
m
=
i
N
x
[
n
]
-
1
disch
(
m
)
(
57
)
v
c
(
i
)
=
∑
m
=
i
N
x
[
n
]
-
1
charg
(
m
)
(
58
)
When N x [n]−1<i, the i th control voltage is set to zero, which means that supporting capacitor i is not being used in the current ripple cycle. Furthermore, higher-indexed switches have precedence over lower-indexed switches. That is, if v c (1), v c (2), . . . , v c (M)>v mmp , switches 1, 2, . . . , M−1 are all disabled, and only switch M is turned on. One exemplary embodiment of a two-step controller is shown in FIG. 28 .
Referring now to FIG. 28 a two-level SC energy buffer controller is shown, where v 0 denotes the backbone capacitor voltage, v i [n] for i={1, 2, . . . , N−1} and v c denotes the sampled supporting capacitor voltage, and v d corresponds to the charge and discharge control signals respectively. The controller includes a capacitor participation optimizer couple to a switch timing determination system. A signal P corresponding to a sampled power level during the current ripple cycle is provided to an input of the capacitor participation optimizer and also to an input of the switch timing determination system. Capacitor participation optimizer processes the signal fed thereto and provides a processed signal N to switch timing determination system.
Switch timing determination system also receives signal P as well as sampled supporting capacitor voltages, v i [n] for i={1, 2, . . . , N−1}.
Switch timing determination system includes an optional norm function processor which normalizes the supporting capacitor voltages provided thereto prior to the signals being coupled to charge and discharge processors which provide signals to respective ones of summing circuits which output charge v c , and discharge signals v d , respectively, to a charge/discharge-signal processor here illustrated as a state machine and in particular, illustrated as a finite state machine (FSM). It should, of course, be appreciated that charge/discharge-signal processor may be implemented as another types of processor depending upon the requirements of the particular application.
Charge/discharge-signal processor has a control ramp system coupled. Control ramp receives a backbone capacitor voltage signal v 0 and provides a rampel control signal to the charge/discharge-signal processor (e.g. an FSM). In response to the signals provided thereto (v c , v d and ramp control signal) the charge/discharge-signal processor provides output signals S 0 -S N-1 , S add and S sub .
As described above, the control ramps are assumed to be perfectly sinusoidal, or rectified sinusoidal, with zero phase error. Practical circuits, however, have imperfections (e.g. distortion and phase error). Practical phase-locked loops, for example, may not guarantee zero steady-state phase error. If a phase error persists between the control ramp and the actual ripple cycle, systematic errors would be introduced to the steady-state voltages of all supporting capacitors, which would result in an increased overall bus voltage ripple. Additionally, the grid voltage may not be perfectly sinusoidal and the ripple voltage may exhibit distortions. Distortion from the assumed sinusoidal profile would introduce unsystematic imbalances in the charge and discharge of the supporting capacitors, which again causes the overall bus voltage ripple to increase.
Therefore, the generated phase-locked signal cannot always be used. Instead, the control ramps can be derived from the backbone capacitor voltage. By passing the AC component of the backbone capacitor voltage through a clamped capacitor circuit, a unipolar control ramp signal from 0V to the peak-to-peak ripple magnitude can be extracted. Similarly, the bipolar control ramp can be created by inverse rectifying the AC component of the backbone capacitor voltage, then processing the resulting signal with a clamped capacitor circuit. This yields a bipolar ramp signal from 0V to the peak ripple amplitude. Alternatively, both control ramp signals can be produced digitally after sampling the backbone capacitor voltage.
Generating the ramp functions directly from the backbone capacitor voltage guarantees zero distortion and phase error between the control signals and the actual ripple cycle. Furthermore, normalization of the sampled signals may not be required because the normalization factor is the inverse of the peak-to-peak ripple amplitude on the backbone capacitor. In practice, implementing control logic with the large voltages may not be feasible. Therefore, resistive dividers can be employed as long as the divider ratio is consistent between the control ramp generation and the supporting capacitor sampling.
It should be noted that it is not necessary to have a pre-charge circuit when using the control strategy described in the previous sections. By adjusting the switch timings, the controller automatically introduces imbalances between the allowable charge and discharge durations of the supporting capacitors so the capacitor voltages reach their reference.
This is a tradeoff. The pre-charge circuit can facilitate the process of charging the supporting capacitors to their reference levels at startup, which allows the system to reach steady-state operation faster. Secondly, the pre-charge circuit can assist in maintaining the charges on unused capacitors. The proposed controller only controls charge and discharge duration on the active supporting capacitors in the ripple cycle; it has no control over the nonparticipating capacitors in reserve. Thus, having a pr-charge circuit adds an extra layer of security to ensure that the capacitors in reserve remain ready in the event of a power level increase. Finally, by using a pre-charge circuit to set up all the capacitors to known states initially, the SC energy buffer can in principle be operated without a requirement to monitor the voltage on every supporting capacitor in the buffer.
Aside from the overvoltage protection circuitry commonly found in PFC and inverter controllers, the SC energy buffer controller can incorporate an additional layer of protection to guard against large transients between sampling periods. Switching duration computations are performed at the beginning of each sampling period. If the transient between sampling periods is large enough, the computed and ideal switch timings may differ significantly, resulting in over- or under-buffering conditions.
“Over-buffering” occurs when the actual ripple magnitude is significantly smaller than the expectation of the controller. When such an event occurs, the boost and drop in the bus voltage from switching the supporting capacitors will be greater than what is actually needed. Similarly, “under-buffering” occurs when the actual ripple magnitude is significantly larger than the expectation of the controller. Consequently, the boost and drop in the bus voltage from switching the supporting capacitors will be smaller than the required values. Both over- and under-buffering conditions result in larger than expected ripple.
Such undesirable conditions can be avoided by introducing feedforward compensation, i.e., a forced resampling triggered on over- and undervoltage thresholds. Once the bus voltage exceeds the defined thresholds, the controller resamples the current power level and the supporting capacitor voltages to recompute the number of active capacitors required and recalculate the switch timings. In over-buffering conditions, the recomputed number of active capacitors would be decreased, whereas in under-buffering conditions, the recomputed number of active capacitors would be increased.
The unipolar 1-8 SC energy buffer and the bipolar 1-4 SC energy buffer design examples have been successfully implemented and simulated in SPICE with a 500 W inverter. The system is implemented with control ramps generated from the backbone capacitor voltage to avoid distortion and phase errors. In addition, the minimum duration constant k is set to 0.9 and a pre-charge circuit is configured to manage the voltages of supporting capacitors in reserve. The steady-state bus voltage ripple and the backbone capacitor feedback voltage are shown in FIGS. 29A-29D . The simulated result matches the analytical solution quite well. The external inverter control manages the backbone voltage and holds it to 250V. The peak-to-peak ripple is set to 10% by inverting Equations (45) and (46) and solving for the required capacitance.
FIGS. 29A, 29B are plots of voltage (V) vs. time (seconds) which illustrate steady-state bus voltage waveforms of a 1-9 SC energy buffer with unipolar switching experiencing increasing power level and (b) 1-4 bipolar SC energy buffer with bipolar switching experiencing decreasing power level. In FIGS. 29A, 29B , the power level increases from 96 W to 480 W with +48 W step size every 50 ms where v 0 denotes the backbone capacitor voltage, and v i for i={1, 2, . . . , N−1} denotes the supporting capacitor voltage.
FIGS. 29C, 29D are plots of voltage (V) vs. time (seconds) which illustrate steady-state bus voltage waveforms of a 1-9 SC energy buffer with unipolar switching experiencing increasing power level and 1-4 bipolar SC energy buffer with bipolar switching experiencing decreasing power level where the power level decreases from 480 W to 96 W with a −96 W step size every 50 ms and where v 0 denotes the backbone capacitor voltage, and v i for i={1, 2, . . . , N−1} denotes the supporting capacitor voltage.
The bus voltage in the unipolar switching energy buffer exhibits a power-dependent mean as discussed above, and remains well above the grid voltage to retain control. As the power level increases, more supporting capacitors become involved in ripple buffering, as demonstrated by the capacitor activities in the subplot of FIGS. 29A-29B . Conversely, the bus voltage in the bipolar switching energy buffer has a constant mean over the all power levels as shown in FIGS. 29C-29D . With decreasing power level, the supporting capacitors sequentially become inactive, leaving only the backbone capacitor to buffer the small power ripple.
In a sampled system, the worst-case behavior occurs if a large transient occurs immediately after sampling has taken place. Thus, this is the case chosen for the transient response characterization. Positive and negative 30% steps in input power level are introduced to the inverter with the bipolar 1-4 SC energy buffer.
FIGS. 30A, 30B are plots of voltage (V) vs. time (seconds) which illustrate transient bus voltage response of a bipolar 1-4 SC energy buffer in a solar inverter due to 30% input power step where the power steps from 480 W to 336 W at 50 ms and back to 480 W at 100 ms. and where the second supporting capacitor voltage deviates from its reference value shortly after 100 ms, but the two-step controller brings it back to its reference level in less than two ripple cycles. As can be seen in FIGS. 30A, 30B the positive step in power causes an under-buffering condition until the bus voltage crosses the upper threshold. It should be noted that the over and undervoltage thresholds are defined to be 1.5 times the ripple specification, i.e. 15% peak-to-peak from 250V, and shown in FIG. 30 as dotted lines. At this point, the controller immediately resamples and recomputes the switch timings to pull the bus voltage back within bounds. Even though the transient may cause some supporting capacitor voltages, v 2 in this particular example, to deviate from their reference values, the two-step controller is able to bring the system back to steady-state in just a few cycles, without any unacceptably large transient ripple.
Switched-capacitor energy buffers have been shown to achieve much better energy utilization than their single electrolytic counterparts. However, overshooting and the possibility of losing control to the grid are major concerns. The proposed control strategy can potentially minimize the possibility of such undesirable behaviors by maintaining an appropriate number of supporting capacitors in reserve to guard against sudden transients in power level.
Two SC energy buffers—1-8 with unipolar switching and 1-4 with bipolar switching—have been examined in a 500 W inverter. The simulated models show excellent agreement with the calculated results. Furthermore, the system is able to maintain a minimum bus voltage of 250V and limit the peak-to-peak ripple to 10% under steady-state operation. It is also shown that the new control strategy can successfully maintain the ripple specification under significant power level transients.
FIG. 31 shows an example embodiment of the stacked switched capacitor energy buffer: the 2-6 bipolar SSC energy buffer. This topology has two backbone capacitors, C 11 and C 12 ; six supporting capacitors, C 21 , C 22 , C 23 , C 24 , C 25 , and C 26 ; and twelve switches, S 11 , S 12 , S 21 , S 22 , S 23 , S 24 , S 25 , S 26 , Sh 1 , Sh 2 , Sh 3 , and Sh 4 . This circuit can keep the bus voltage ripple within 10% of nominal value when designed and operated in the manner described below.
The eight capacitors are chosen to have identical capacitance, but different voltage ratings. The two backbone capacitors, C 11 and C 12 , have voltage rating of 1.6Vnom, where Vnom is the nominal value of the bus voltage (Vbus). The voltage rating of the six supporting capacitors is as follows: 0.6Vnom for C 21 , 0.5Vnom for C 22 , 0.4Vnom for C 23 , 0.3Vnom for C 24 , 0.2Vnom for C 25 and 0.1Vnom for C 26 . A precharge circuit (not shown in FIG. 31 , but discussed below) ensures that the following initial voltages are placed on the eight capacitors: 0.4Vnom on C 11 , 0.4Vnom on C 12 , 0.5Vnom on C 21 , 0.4Vnom on C 22 , 0.3Vnom on C 23 , 0.2Vnom on C 24 , 0.1Vnom on C 25 , and 0V on C 26 .
Referring now to FIG. 31 , one particular example of an n-m bipolar stacked switched capacitor energy buffer circuit is shown in FIG. 31 where n=2 and m=6 also called a 2-6 bipolar stacked switched capacitor energy buffer circuit.
The exemplary circuit includes a first block of parallel coupled switches and capacitors S 11 , C 11 , S 12 , C 12 and a second block of parallel coupled switches and capacitors S 21 , C 21 , S 22 , C 22 , S 23 , C 23 , S 24 , C 24 , S 25 , C 25 , S 26 , C 26 . The first and second blocks are coupled in series across a bus voltage V bus . Switches Sh 1 , Sh 2 , Sh 3 , Sh 4 are disposed in the second block to provide selected signal paths between the first and second blocks.
As noted above, the capacitors are preferably of a type that can be efficiently charged and discharged over a wide voltage range (e.g., film capacitors). The switches are disposed to selectively couple the capacitors to enable dynamic reconfiguration of both the interconnection among the capacitors and their connection to a buffer port. The switches are cooperatively operated as a switching network such that the voltage seen at the buffer port varies only over a small range as the capacitors charge and discharge over a wide range to buffer energy.
By appropriately modifying switch states of the SSC energy buffer circuit, the SSC energy buffer circuit absorbs and delivers energy over a wide individual voltage range, while maintaining a narrow-range voltage at the input port. This enables maximal utilization of the energy storage capability.
A bipolar stacked switched capacitor energy buffer circuit can be controlled as follows. Rather than charging the n capacitors only in series with the m capacitors, a state can be introduced by turning S h3 and S h4 (or S h1 and S h2 ) on at the same time in which the n capacitor is charged directly. An example of the modified control is shown in FIG. 32 for the circuit 300 (the 2-4 bipolar SSC energy buffer circuit) of FIG. 31 . The modified control is described herein in the section entitled: “Enhanced Bipolar Stacked Switched Capacitor Energy Buffer”. With this modified control, and assuming that all m and n capacitors have the same capacitance, the expression for energy buffering ratio, γ b becomes:
γ
b
=
n
n
FIG. 32 shows the switch states, the capacitor voltages and the resulting bus voltage for the 2-6 bipolar SSC energy buffer over a complete charge and discharge cycle. When the energy buffer starts charging up from its minimum state of charge, Sh 1 , Sh 4 , S 21 and S 11 are turned on with all the other switches turned off. In this state, C 11 and C 21 are connected in series and charged until the bus voltage rises from 0.9Vnom to 1.1Vnom. At this instant the voltage of C 21 (V 21 ) reaches 0.6Vnom and the voltage of C 11 (V 11 ) reaches 0.5Vnom. Then S 21 is turned off and S 22 is turned on; and the bus voltage drops back down to 0.9Vnom. Then as the charging continues, the voltage of C 22 rises to 0.5Vnom and the voltage of C 11 reaches 0.6Vnom and the bus voltage again reaches 1.1Vnom. Next S 22 is turned off, S 23 is turned on and C 23 is charged.
This process is repeated until C 26 is charged. At this stage all the supporting capacitors are at their maximum voltage; the voltage of the backbone capacitors is: Vnom on C 11 and 0.4Vnom on C 12 ; and the bus voltage is 1.1Vnom. Next Sh 1 and Sh 4 are turned off, and Sh 3 and Sh 2 are turned on. This connects C 26 , and the other supporting capacitors, in reverse orientation with C 11 and the bus voltage again drops to 0.9Vnom. Now C 11 can continue to charge up through the now reverse-connected supporting capacitors through a process similar to the one described above, except that the supporting capacitors are discharged in reverse order, i.e., first through C 26 , then through C 25 , and so on until finally through C 21 . At this stage C 11 is fully charged to 1.6Vnom and charging of C 12 must begin. For this the h-bridge switches are again toggled (i.e., Sh 3 and Sh 2 are turned off; and Sh 1 and Sh 4 are turned on), S 11 is turned off and S 12 is turned on. The charging process for C 12 is identical to the charging process for C 11 , as shown in FIG. 32 . During the discharge period, the capacitors C 11 and C 12 are discharged one at a time through a process that is the reverse of the charging process. Hence, the voltage waveforms during the discharge period are a mirror of those in the charging period. Throughout the charging and discharging period of this energy buffer, the bus voltage stays within the range 0.9Vnom-1.1Vnom. Hence, the 2-6 bipolar SSC energy buffer operating in this manner has a bus voltage ripple ratio (Rv) of 10%. Furthermore, it has an energy buffering ratio (T b ) of 79.6%.
n-m Bipolar SSC Energy Buffer
The capacitors that buffer most of the energy in the circuit of FIG. 31 are the backbone capacitors C 11 and C 12 . Therefore, by adding additional backbone capacitors in parallel with C 11 and C 12 the energy buffer could potentially achieve better buffering performance. The number of supporting capacitors can also be changed. To evaluate the impact of the number of backbone and supporting capacitors on the performance of the energy buffer, the topology of FIG. 31 is extended by incorporating n backbone capacitors and m supporting capacitors, as shown in FIG. 37 . The energy buffering ratio for this n-m bipolar SSC energy buffer (with n backbone capacitors of equal value C 1 and m supportive capacitors of equal value C 2 ) is given by:
Γ b =nCl (1+2 mR v ( C 2/( C 1 +C 2))) 2 −(1−2 mR v ( C 2/( C 1 +C 2))) 2 / Equation (59)
Referring to FIG. 37 , as noted above, an n-m bipolar SSC energy buffer circuit can be realized by adding more capacitors to the first and second of circuitry, 502 , 504 shown in FIG. 37 circuit 500 . Note that the capacitor that does the energy buffering in the circuit 500 is the capacitor C 11 in the second set of circuitry 504 . Therefore, by replacing C 11 alone with a plurality of “legs” in parallel, each “leg” comprising the series connection of a capacitor and switch, better buffering performance can be achieved.
The circuit 500 ′ includes a first set of circuitry 502 ′ and a second set of circuitry 504 ′. The first set of circuitry 502 ′ includes capacitors C 21 , C 22 , . . . , C 2m (referred herein as m capacitors) and switches S 21 , S 22 , . . . , S 2m in series with a respective one capacitor, and the “legs” formed by each switch-capacitor pair in parallel. The first set of circuitry 502 ′ also includes switches S h1 , S h2 , S h3 , S h4 (e.g., an H-bridge). The second set of circuitry 504 includes capacitors C 11 , C 12 , . . . , C 1n (referred herein as n capacitors) and switches S 11 , S 12 , . . . , S 1n in series with a respective one capacitor, and the “legs” formed by each switch-capacitor pair in parallel.
The m capacitors in the first set of circuitry 502 in this case have to switch at a higher switching frequency. The energy buffering ratio for this n-m bipolar SSC energy buffer (with n capacitors of equal value C 1 and m capacitors with equal value C 2 ) is given by:
γ
b
=
n
C
1
n
C
1
FIG. 38 shows the variation in energy buffering ratio, Γ b , (with C 1 equal to C 2 ) as a function of the number of backbone capacitors n and the number of supporting capacitors m for three different values of voltage ripple ratio Rv. These plots indicate that there is an optimal number of supporting capacitors that should be used for a given number of backbone capacitors in order to maximize the energy buffering ratio. Note that this optimal number of supporting capacitors depends on the value of allowed voltage ripple ratio.
These plots can be used to select the optimal number of backbone and supporting capacitors to maximize the energy buffering ratio for a given bus voltage ripple ratio. If a larger voltage ripple ratio is allowed, a high energy buffering ratio can be achieved with fewer backbone and supporting capacitors. For a fixed number of backbone capacitors, a lower voltage ripple ratio requires a larger number of supporting capacitors if maximum energy buffering is to be achieved.
However, increasing the number of supporting capacitors also increases the complexity of the circuit and the switching frequency of the switches associated with the supporting capacitors (S 21 -S 2 m ). For an Rv of 10% with 2 backbone capacitors, the optimal number of supporting capacitors is 33 (see FIG. 34A ); hence the choice of the 2-6 bipolar SSC energy buffer to meet a 10% voltage ripple requirement. Note that for an Rv of 10%, with 8 backbone and 8 supporting capacitors, an energy buffering ratio of 91.6% can be achieved. Hence, the SSE energy buffer achieves performance similar to the 8-6-5-4-3 parallel-series switched capacitor circuit of with only 16 capacitors and 20 switches instead of 120 capacitors and 41 switches.
To validate the proposed concept an exemplary 2-6 bipolar SSC energy buffer, similar to the one described herein and shown in FIG. 31 was designed and built. The exemplary circuit is designed as the energy buffer for a power factor correction (PFC) front-end of a two-stage single-phase ac to dc power converter as shown in FIG. 35A, 35B . The SSC energy buffer replaces the electrolytic capacitor normally connected at the output of the PFC. To simplify the implementation, a load resistor is used in place of the second-stage de-dc converter. The SSC energy buffer is designed to meet a 10% bus voltage ripple ratio requirement on a 320 V dc bus with a maximum load of 135 W, as listed in Table I.
TABLE I
Design specifications for the exemplary
2-6 bipolar SSC energy buffer.
Design Specification
Value
Maximum load power (Pload(max))
135 W
Bus voltage (Vbus)
320 V
Voltage ripple ratio (Rv)
10%
The PFC used for this exemplary circuit is a 400 W evaluation board from STMicroelectronics that uses their transition-mode PFC controller (L6562A). This controller operates the boost PFC at the boundary between continuous and discontinuous conduction mode by adjusting the switching frequency. The evaluation board has a 330 μF electrolytic capacitor at the output of the PFC, and according to the PFC datasheet can maintain a voltage ripple ratio of 2.5%, while supplying a 400 W load at a bus voltage of 400 V. It has been experimentally verified that a 40 μF electrolytic capacitor is sufficient to support 135 W of output power with 10% voltage ripple ratio. The total volume of the 40 μF, 450 V electrolytic capacitor used for this verification is approximately 9 cm 3 . The energy buffer that replaces this electrolytic capacitor consists of three functional blocks: the energy buffer power circuit, the precharge circuit and the control unit, as shown in FIGS. 35A, 35B . In addition, the energy buffer needs to provide a feedback signal to the PFC for its proper operation. The design of each of these four elements is discussed below.
Energy Buffer Power Circuit
As shown in FIG. 34B , to achieve a voltage ripple ratio of 10% with a two-backbone-capacitor (n=2) bipolar SSC energy buffer, the optimal number of supporting capacitors is six, (i.e., m=6). Hence in the exemplary circuit, the electrolytic capacitor is replaced by a 2-6 bipolar SSC energy buffer. To meet the 10% voltage ripple requirement at the 320 V bus voltage and the 135 W output power level, the eight capacitors of the SSC energy buffer have to be 2.2 micro-Farads each. The required voltage rating of these film capacitors is different and ranges from 32 V to 512 V. However, for simplicity and to provide adequate safety margin, 700 V film capacitors are used as the two backbone capacitors and 250 V capacitors are used as the six supporting capacitors. All the switches are implemented using silicon power MOSFETs.
Switches S 11 S 12 , S 21 , S 22 , S 23 , S 24 , S 25 and S 26 are implemented with reverse voltage blocking capability.
Precharge Circuit
An important part of the SSC energy buffer is the precharge circuit. When the system starts, the precharge circuit draws power from the PFC to charge the individual capacitors of the energy buffer to the desired initial voltage levels. The precharge circuit designed here uses a linear regulator operated as a current source as shown in FIG. 36 . The linear regulator used is Supertex's LR8 with a maximum output current of 20 mA. The linear regulator can be disconnected from the energy buffer power circuit by two isolating switches Sp 1 and Sp 2 . The precharge circuit is controlled by an ATMEL ATmega2560 microcontroller.
The flow chart of the precharge control is shown in FIG. 37 . A scaled down version of the voltage across each capacitor is compared with a specified reference provided by the microcontroller through a digital to analog converter (DAC). The results of the comparison are fed back to the microcontroller to trigger an interrupt. During precharge, the microcontroller turns the switches on or off appropriately to connect the current source to the capacitor that needs to be charged. The states (on or off) of the switches for charging a particular capacitor during the precharge period are shown in Table II.
TABLE II
State of the switches during precharge of each of the eight capacitors
of the 2-6 bipolar SSC energy buffer. Blank cell indicates the switch is off.
C 11
C 12
C 21
C 22
C 23
C 24
C 25
C 26
S 11
on
S 12
on
S 21
on
S 22
on
S 23
On
S 24
on
S 25
on
S 26
on
S h1
S h2
on
on
S h3
S h4
on
on
On
on
on
on
S p1
on
on
on
on
On
on
on
on
S p2
on
on
on
on
On
on
on
on
S s
on
on
On
on
on
on
First Sp 1 , Sp 2 , S 21 , Sh 4 and Ss are turned on, and all the other switches are turned off to charge C 21 . The microcontroller senses the voltage of C 21 (through the voltage divider formed by R 21 and R 22 ) and compares it with the specified precharge voltage (0.5Vnom=160 V). Once the voltage of C 21 reaches 160V, S 21 is turned off and S 22 is turned on to charge C 22 to its specified precharge level. Similarly, C 23 , C 24 , C 25 and C 26 are charged one at a time to their designed initial level. Once C 26 is charged, S 26 , Sh 4 and Ss are turned off, and Sh 2 and S 11 are turned on to charge C 11 . Now the microcontroller senses the voltage of C 11 (through the voltage divider formed by R 11 and R 12 ) and compares it with the specified precharge voltage (0.4Vnom=128 V). Once the voltage of C 11 is larger than 128 V, S 11 is turned off and S 12 is turned on to charge C 12 . Once all the capacitors are precharged, the precharge circuit is disconnected from the SSC energy buffer by switches Sp 1 and Sp 2 , and the energy buffer enters normal operation.
Control
The normal operation of the energy buffer is also controlled by a state machine implemented in the ATMEL ATmega2560 microcontroller. The state machine controls the state (on or off) of the twelve switches in the SSC energy buffer power circuit. The state machine has a total of 24 states, with each state corresponding to a unique and valid combination of the states of the twelve switches, as shown in Table III.
States
S 21
S 22
S 23
S 24
S 25
S 26
S 11
S 12
S h1
S h2
S h3
S h4
1
on
On
on
on
2
on
On
on
on
3
on
On
on
on
4
on
On
on
on
5
on
On
on
on
6
on
On
on
on
7
on
On
on
on
8
on
On
on
on
9
on
On
on
on
10
on
On
on
on
11
on
On
on
on
12
on
On
on
on
13
on
on
on
on
14
on
on
on
on
15
on
on
on
on
16
on
on
on
on
17
on
on
on
on
18
on
on
on
on
19
on
on
on
on
20
on
on
on
on
21
on
on
on
on
22
on
on
on
on
23
on
on
on
on
24
on
on
on
on
The flow chart of the normal operation mode control logic of the energy buffer is shown in FIG. 37 . In this flow chart, s denotes the current state of the state machine. The energy buffer starts normal operation in state 1 (i.e., s=1), which corresponds to minimum energy stored in the buffer, and starts to charge up. Once the bus voltage reaches the maximum allowed voltage, 1.1Vnom (352 V), the UP interrupt is triggered and the state is incremented by one (i.e., s=s+1). The microcontroller turns the appropriate power switches on or off to match the configuration for the new state. This drops the bus voltage back to 0.9Vnom (288 V), and the charging of the energy buffer continues until it again reaches the upper voltage limit. This process is repeated as long as the energy buffer is being charged and it has not reached state 24. Once the energy buffer has reached state 24, the state machine stays in state 24 even if it receives additional cUP interrupts. This helps protect the energy buffer to a certain extent in case load power exceeds its design specifications. During this overload condition the energy buffer looks like a 1.1 _F capacitor to the external system. The energy buffer will return to normal operation once the load power returns to the design range.
During discharge of the energy buffer, the DOWN interrupt is triggered when the bus voltage reaches the minimum allowed voltage, 0.9Vnom (288 V). This decrements the state by one (i.e., s=s−1). The microcontroller turns the appropriate power switches on and off to match the configuration for the new state and the bus voltage increases to 1.1Vnom (352 V). This process is repeated each time the bus voltage reaches the lower voltage limit until it has reached state 1. As in the case of charging, to protect the energy buffer, the state machine stays in state 1 even if it receives additional DOWN interrupts. Hence during normal operation at maximum power, the state machine will iterate through states 1 through 24 in a sequential manner, first going from 1 to 24 as it charges, and then returning from 24 to 1 as it discharges, and this process is repeated as long as the energy buffer is in normal operation.
Artificial Voltage Feedback
In a conventional system with an energy buffering electrolytic capacitor at the output of the PFC, the PFC uses the bus voltage (i.e., the voltage across the buffering capacitor) to control its output current. The bus voltage is scaled down by a resistive divider and fed back to the PFC control chip.
Since the bus voltage is a good measure of the energy stored in the capacitor, this feedback mechanism ensures that the average output power from the PFC matches the power drawn by the do load and the system stays stable. However, when the electrolytic capacitor is replaced with the SSC energy buffer, the bus voltage is no longer a true representation of the energy stored in the energy buffer. Hence, an artificial signal must be generated (and fed back to the PFC control chip) that represents the energy stored in the energy buffer and mimics the bus voltage of the electrolytic capacitor. In the exemplary circuit this function is performed by a second ATMEL ATmega2560 microcontroller.
In the precharge mode, the SSC energy buffer behaves simply like two capacitors connected in series. Hence, during this period, the bus voltage reflects the energy stored inside the two capacitors and so the voltage that needs to be fed back is simply a scaled version of the bus voltage.
Once the energy buffer enters normal operating mode, its stored energy increases monotonically as it goes from state 1 to state 24 and then decreases monotonically as it returns to state 1. The energy that gets stored in the energy buffer as it goes from state 1 to state 24 is given by:
Δ
E
(
t
)
=
∑
i
=
1
N
1
2
(
Ci
(
Vi
(
t
)
2
-
V
i
0
2
)
Equation
(
60
)
Where:
N is the total number of capacitors in the energy buffer (eight in the 2-6 bipolar SSC case);
Ci is the capacitance of capacitor i;
Vi(t) is the voltage of capacitor i at time t; and
V t0 is the initial voltage of capacitor i after it is precharged.
In the exemplary circuit all eight capacitors have the same capacitance Cb (equal to 2.2 _F). The effective energy in the energy buffer as a function of time is given by:
Eb ( eq )( t )=½ C eq V min 2 +ΔE ( t ) Equation (61)
where Ceq is an equivalent capacitance for this energy buffer valid while it is operating in normal operating mode, and is given by:
C
eq
=
2
∫
t
1
t
2
p
(
t
)
ⅆ
t
V
t
2
2
-
V
t
1
2
Equation
(
62
)
It should be noted that Eb(eq) as given by Equation 61 is not the actual energy in the energy buffer but rather the apparent energy.
Here p(t) is the power flowing into the energy buffer, and Vt1 and Vt2 are the voltages at beginning (time t1) and the end (time t2) of the charging period, respectively. For the exemplary system, Ceq is equal to 26.4_F. Hence, the voltage that needs to be fed back in normal operating mode is given by:
V
fb
(
t
)
=
C
eq
V
min
2
+
2
Δ
E
(
t
)
C
eq
Equation
(
63
)
This feedback signal reflects the apparent energy stored in the energy buffer. While the expression given by Eq. 8 for the normal operating mode feedback signal can be implemented, it is simpler to implement an approximation to this expression which works just as well within the resolution of an 8-bit digital to analog converter (DAC). The approximate feedback signal is derived assuming that the feedback voltage signal is linear between two switching instances and the current flowing into or out of the energy buffer is constant (i.e., current has a square profile).
This approximate feedback voltage is given by:
V fb(approx) ( t )= V min +( V max −V min )( i/ 24)+( V bus ( t )− V min )( C b /2 C eq ) Equation (64)
It should be noted that the switched-capacitor energy buffer concepts, systems, circuits and techniques described herein enable the use of smaller capacitors with lower voltage ratings in place of a single large capacitor with high voltage rating. Thus, it is possible to construct an inverter potentially free of electrolytic capacitors in order to enable long-life operation. In addition, the concepts, systems, circuits and techniques described herein improve capacitor energy utilization in inverters significantly. It also offers great opportunities in reducing bus voltage ripple sizes while introducing negligible increase in energy storage volume.
Described herein are a variety of novel approaches to the distribution of energy conversion and control throughout a solar array. The architecture choices presented here affect the power electronics implemented at the module. These choices afford new opportunities for the control and processing of energy that may enhance system and grid-interaction stability. They also offer the possibility of removing certain types of components from troublesome areas of the system, e.g., magnetics behind panels and electrolytic capacitors in the inverter. Described herein is a “system” view of a solar array, and a description of potential optimizations that maximize energy extraction to the grid with the improved stability while potentially minimizing expense and maximizing field life.
Switched-capacitor DC-DC converters have been shown to be beneficial at all levels of solar energy extraction. Notably, utilizing these converters at the cell level may lead to reduction in production cost or different opportunities for the manufacturer of solar panels. Common centroid layout can potentially keep MPPT converters away from extreme conversion ratios where their conversion efficiencies may degrade.
As generation on the utility grid becomes increasingly distributed due to the influx of renewable energy sources, the uncertainty of local grid impedance will increase. Thus, stability of the electrical power network is becoming a growing concern. The proposed architecture can potentially minimize the possibility of unstable interactions with the grid by exploiting the utility of feedforward information from the PV array current sink. The technologies in this architecture could be applied in other areas as well, including power-factor correcting converters.
Having described preferred embodiments of the concepts, systems, circuits and techniques described herein, it will now become apparent to those of ordinary skill in the art that other embodiments incorporating these concepts may be used. For example, it should now be appreciated that one can apply the topologies described herein to rectifier systems (e.g. for grid-connected power supplies) as well and for bidirectional power flow converter systems. Accordingly, it is submitted that that the concepts, systems, circuits and techniques described herein, should not be limited to the described embodiments but rather should be limited only by the spirit and scope of the appended claims. | Described is a method and apparatus for per-panel photovoltaic energy extraction with integrated converters. Also described are switched-capacitor (SC) converters have been evaluated for many applications because of the possibility for on-chip integration; applications to solar arrays are no exception. Also described is a comprehensive system-level look at solar installations, finding possibilities for optimization at and between all levels of operation in an array. Specifically, novel concepts include new arrangements and options for applying switched-capacitor circuits at 3 levels: for the panel and sub-panel level, as part of the overall control strategy, and for ensuring stable and robust interface to the grid with the possibility of eliminating or reducing the use of electrolytic capacitors. | 8 |
BACKGROUND AND SUMMARY OF THE INVENTION
The invention relates to packaging and shipping systems and in particular to packaging of materials and items to be secured as a unit load or to be secured to a shipping and transporting means, such as a pallet. Specifically, it relates to such systems using plastics stretch film (a high cling film) as the binding and securing agent, and more specifically to an apparatus for such systems that is manually operable with one hand, leaving the other hand free to stabilize the load being secured.
A need has existed for some time for simple means for applying plastics stretch film material. U.S. Pat. Nos. 4,179,081 and 4,248,392, both entitled "Apparatus for Application of Plastics Stretch Films", invented by the present applicant, solved some of the problems and provided a simple and economical means to do the work. However, problems still remain when binding and securing light weight materials and items as a unit load or to a shipping and transporting means, such as a pallet or slip sheet. The present invention solves those problems.
The present invention is for manual operation, but may also be applied to machine applications of the plastics stretch film. The present invention is a one-hand operated dispensing unit which frees the other hand for steadying or stabilizing light weight materials or items, particularly when stacked. The light-weight items may be stacked for binding as a unit load or stacked on a shipping or transporting means as aforementioned. The one-hand device is especially useful when starting the binding wrapping of the plastics stretch film, and when binding the top layers in a stack. In both cases the free hand can be used to hold steady the materials or items and prevent them from sliding out of position as the film is applied for the initial layer or layers of wrapping when the light weight materials or items are not stable at their interface with each other.
The present one-hand device has a simple means included so that it can be converted to a two-hand operation once the materials or items are initially bound or secured sufficiently for a tighter wrapping for movement or for shipment. The simple means for converting to a two-hand device also serves as an efficient means for packaging a pair of the one-hand devices or a package of pairs of the one-hand devices.
In the prior art two methods were available for applying the plastics stretch film material to materials and units to be packaged or secured as hereinbefore described. In addition, now in the prior art, are the two-hand devices of the cited United States Patents, invented by the present applicant.
As described in the two cited U.S. patents, one of the prior art methods is to use a very expensive automatic machine, and the other is to use a commercial manually operated grabbing or holding device which also is very expensive and complicated. The inventions of the two cited United States Patents overcome the problems of the prior art by providing a simple manually operated means for applying the film using two hands, but was unwieldy and unuseable when binding or securing light weight materials or items as hereinbefore described. The present invention overcomes the problems.
The present invention, when used in the manner of the conversion to a two-hand device, also provides another advantage. The conversion means permits the addition of a second one-hand device so that a "roping" effect can be accomplished with a double wrap of narrow strips of plastics film for a tighter and more secure binding of a unit package or load. The details of this "roping" operation is explained hereinafter.
In the prior art the two hand device was unwieldy, as aforementioned, when binding and securing light weight materials and items, particularly when piled or stacked. The cantilever action of the two-hand device was painful and caused a severe bending moment on the wrist when held in one hand. With the extreme cantilever action it was found to be impossible with one hand to make the initial binding wrap on light-weight materials or items.
The very low cantilever action of the one-hand device of the present invention permits the initial binding of light-weight materials and items without the overpowering stress in the wrist of the user. At the same time, the other hand is available to steady or stabilize the pile or stack of materials or items. The completion of the binding and securing of the unit or load can then be accomplished by the continued use of the one-hand device of this invention, or a second one-hand device can be added by the novel and unique coupling means so that it can be operated like a two-hand device. The novel and unique coupling means also provides a simple way of shipping a pair of one-hand units, or packages of a plurality of pairs of one-hand units, as well as being the means by which a pair of one-hand devices can be used like a two-hand device.
The novel and unique coupling means makes it possible to apply the plastics film material in a roping manner of two narrow flat sheets of the plastics film. The roping method adds a criss-cross or "X" pattern that increases the strength and holding power of the plastics film binding wrap.
The roping effect is achieved when two one-hand operated devices are coupled together and periodically or intermittently, while stretching and wrapping the film around materials or items, the hand grip ends are changed to the opposite hands so as to criss-cross lap the flat plastics sheets in the wrapping procedure.
The control of the amount of tension applied to the plastics film to stretch it and to provide a tight gripping force upon the materials or items being bound into a unit or load is by the direct pressure or squeeze of the operator's one hand on the grip end of the one-hand device. The grip or squeeze by the operator is applied on a flexible tube-like device, the flexible tube-like device or grip means being applied around an extended end of the core means of a one-hand roll of the plastics film material.
The coupling means for using two one-hand devices simultaneously and for shipping the devices in pairs is a dowel-like member that is dimensionally longer than the core length of a single one-hand device, but dimensionally shorter than two core lengths of a one-hand device. To couple two one-hand devices to each other for operating as a two-hand device or for shipping a pair of units, the dowel-like member is slideably inserted into the two hollow cylindrical cores of each of the two one-hand units. The diameter of the dowel-like member is dimensionally less than the inside diameter of the core. The grip means on each extended core end of the two one-hand devices are then held and the combination used like a two-hand device.
When using the one-hand device in one hand, the dowel-like member can be left out or placed in the one-hand device in use. If, momentarily, the one-hand device needs a temporary support, the free hand can grip the dowel-like member where it protrudes from the core of the one-hand device in use. The dowel-like member, being dimensionally smaller in diameter than the inside diameter of the core, will move freely in the core. The dowel-like member can, in this case, be gripped tightly by the free hand as only temporary support is necessary.
Two types of hand grips are disclosed in the present invention as components of the invention. One is a tubular-like member with a closed end. The other is an improved hand grip that is also tubular-like, but is improved with a flange means on one end and an inward turned lip on the other end instead of a closed end.
It is, therefore, an object of this invention to provide a plastics film dispensing means that is operable with one hand.
It is another object of this invention to provide a one-hand operated plastics film dispensing means that has a low cantilever action on the wrist of the user.
It is also an object of this invention to provide a one-hand operated plastics film dispensing means in which the operator can "feel" the movement and tension condition through the hand on the flexible hand grip of the device, while the free hand is available to steady and stabilize light weight materials and items being bound and secured as a unit or for shipment.
It is yet another object of this invention to provide a one-hand operated plastics film dispensing means that has a simple coupling means for removably and revolvably affixing a second one-hand operated plastics film dispensing means to the first plastics film dispensing means so that the two one-hand operated plastics film dispensing means may be operated as a two-hand plastics film dispensing means.
It is still another object of this invention to provide a one-hand operated plastics film dispensing means that can apply two plastics films in a roping manner when coupled with a second one-hand operated plastics film dispensing means.
Further objects and advantages of the invention will become apparent in the light of the following description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial view of a first embodiment of a one-hand operated dispensing means for plastics film;
FIG. 2 is a pictorial view of a second embodiment of a first one-hand operated dispensing means for plastics film coupled to a second one-hand operated dispensing means for two-hand operation;
FIG. 3 is an exploded side view of FIG. 2.
FIG. 4 is a pictorial view of a flange-type hand grip for the dispensing means of plastics film of FIGS. 1 and 2;
FIG. 5 is a cross sectional view taken on line 5--5 of FIG. 4; and
FIG. 6 is a cross sectional view of a modification of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings and particularly to FIGS. 1 and 2, a first embodiment of the apparatus of this invention is a one-hand operated dispensing means for plastics film and is shown at 10 in FIG. 1. A second embodiment of the apparatus of this invention of a one-hand operated dispensing means for plastics film is shown at 15 in FIG. 2. The second embodiment of a one-hand dispensing means 15 shows two one-hand dispensing means 10 coupled together for operation as a two-hand operated device.
The first embodiment of a one-hand dispensing means 10 for plastics film consists of a core means 20, a single cylindrical flexible hand grip 22 or 52 on one end thereof with a supply of plastics stretch film 24 rolled upon the core means 20 adjacent to and near the opposite end of the core means 20 from the single cylindrical flexible hand grip 22 or 52. A detailed description of the elements and structure of the first embodiment of a one-hand dispensing means 10 for plastics stretch film is provided hereinafter.
The direction of the core wrap of the roll of plastics stretch film 24 on the core means 20 is shown by arrow 26 thereon, however, it is to be understood that the direction of the arrow 26 on such a drawing could be reversed without changing the concept of this invention.
The core means 20 for the first embodiment of a one-hand dispensing means 10 is preferably a hollow tube-like core, however, it is to be understood that a solid rod-like core is within the scope and intent of this invention for the first embodiment. The material for a hollow tube-like core means may be any suitable material such as hard cardboard like material, fiber, plastics, light weight metal, and other similar materials. The core means 20 may be discarded or reused if desired.
The single cylindrical flexible hand grip 22 is hollow and closed at one end 28 only. The inside diameter 30 is a close fit over the outside diameter of core means 20, but with sufficient clearance so that the core means 20 can turn freely within the hand grip 22.
It is to be noted that for initial clarity of illustration, the closed end hand grip 22 is used. However, an improved flange-type hand grip 52 is the preferred embodiment for this invention and is a part thereof. The flange-type hand grip 52 is described in detail later.
The length of the core means 20 can be seen in one piece in FIG. 3 where the hand grip 22 is shown in an exploded relation to the core means 20. The inside diameter 30 of the hand grip 22 is also shown in relation to the outside diameter of the core means 20 in FIG. 3.
The plastics stretch film 24 is rolled upon the core means 20 with a small clearance 32 from the end 34 of the core means 20. This small clearance 32 of the distal edges 36 of the plastics stretch film 24 from the end 34 of the core means 20 provides a small spacing 38 between the distal edges 36 of two rolls of the plastics stretch film 24 when coupled together as in the second embodiment 15 shown in FIG. 2. In FIG. 3 the plastics stretch film 24 is shown in phantom lines for clarity.
The extension 40 of the core means 20 beyond the frontal edges 42 of the roll of plastics stretch film 24 is slightly greater dimensionally than the dimensional length of the cylindrical flexible hand grip 22. The slightly greater dimensional length of the extension 40 of the core means 20 assures that the edges of the open end 44 of the cylindrical flexible hand grip 22 does not touch or interfere with the frontal edges 42 of the roll of plastics stretch film 24.
The clearance thus provided, between the edges of the open end 44 of the cylindrical flexible hand grip 22 and the frontal edges 42 of the roll of plastics stretch film 24, assures that as the roll of plastics stretch film 24 turns or revolves during an application of the film to a unit or load of materials or items it will not rub at a contact or an interface with the edges of the open end 44 of the cylindrical flexible hand grip 22. A rubbing by a contact or interface between the frontal edges 42 and the edges of the open end 44, while the roll of plastics stretch film 24 is turning or revolving, will generate heat by friction and fuse the frontal edges 42 of succeeding adjacent layers of the plastics stretch films 24 to each other. Thus, a portion of the roll of plastics stretch film 24 will be ruined, as the plastics stretch film 24 material tears when pulled apart after such a fusing together of the edges.
The interior surface 50 of the closed end 28 of the cylindrical flexible hand grip 22 interfaces with the hand grip end 46 of the core means 20 and thus prevents the edges of the open end 44 from touching or interfacing with the frontal edges 42 of the plastics stretch film 24, due to the dimensional length of the cylindrical flexible hand grip 22 being less than the dimensional length of the extension 40 of the core means 20.
The cylindrical flexible hand grip 22 may be plastics or any other suitable flexible material. In operation, the user or operator grips the single hand grip 22 on the extension 40 of the core means 20 and gives a slight squeeze to the hand grip 22 in order to "feel" the extension 40 of the core means 20.
In case the initial friction between the hand grip 22 and the core means 20 is too great to obtain a satisfactory "feel" or a free movement, a suitable lubricant, such as a light coating of powder or a wax may be used on the extension 40 or inside the hand grip 22.
As the operator pays out the plastics stretch film 24 during the wrapping of materials or an item, such as to a transporting means, a sufficient grip is maintained on the single hand grip 22 to provide the necessary control of tension on the plastics stretch film 24. The tension is to stretch the film and also to peel the sheet material off of the supply roll of plastics stretch film 24. The control of the tension is gauged by the "feel" of the extension 40 of the core means 20 through the soft flexible hand grip 22.
During this operation of the one hand dispensing means 10, the operator's free hand is used to steady or stabilize the materials or items being bound or secured with the plastics stretch film 24. This steadying or stabilizing is particularly necessary with light weight materials or items which have a tendency to move or slide as the plastics stretch film 24 is pulled against them. Piled or stacked materials or items are particularly unsteady in this manner.
The operator can make a full stop of the turning or revolving of the roll of plastics stretch film 24 and stop the peeling off of layers of plastics stretch film 24 from the roll. To make the stop the operator or user squeezes the cylindrical flexible hand grip 22 tightly. The squeeze of the cylindrical flexible hand grip 22 is a braking action on the turning or revolving core means 20.
The operator or user can have a free running or a controlled peeling off of the layers of plastics stretch film 24 from the roll by a loosening or tightening of the grip on the cylindrical flexible hand grip 22.
Varying the hand squeeze pressure on the cylindrical flexible hand grip 22 permits the control of the paying out of plastics stretch film 24 while also controlling how tightly the plastics stretch film 24 is pulled to provide the wrap to bind and secure the materials or items being packaged or secured. The squeezing of the flexible hand grip 22 provides a braking action that has controlled instantaneous results.
Turning now to the second embodiment of a one-hand operated dispensing means 15, a pictorial view is shown in FIG. 2 and an exploded side view is shown in FIG. 3. It is to be noted that the portion to the left or right in FIG. 3 is also an exploded side view of the first embodiment of a one-hand operated dispensing means 10.
The second embodiment is the use of two one-hand dispensing means 10, coupled together by a coupling means 48, to form the second embodiment of a one-hand operated dispensing means 15.
Note that in coupling the two one-hand dispensing means 10 together with the coupling means 48, the two one-hand dispensing means 10 are oriented in relation to each other by placing the two ends 34 of the two core means 20 facing toward each other. With two one-hand dispensing means so oriented the coupling means 48 is removably and slideably inserted into each of the hollow tube-like core means 20 so as to maintain the orientation. In FIG. 3 the plastics stretch film on the core means 20, is shown in phantom lines for purposes of clarity.
The coupling means 48 is rod-like and may be a solid, the preferred embodiment, but may also be of a tubular configuration. The outside diameter of the coupling means 48 is dimensionally smaller than the inside diameter of the hollow tube-like core means 20. The hollow tube-like core means 20 is able to turn or revolve freely on the coupling means 48 when assembled and when the plastics stretch film 24 is being payed out during an application.
The coupling means 48 is dimensionally longer than one core means 20 so that if and when one end of the coupling means 48 is inside at one end of one of the core means 20, and touching or interfacing with the inside surface 50 of the closed end 28 of the cylindrical flexible hand grip 22, the opposite end of the coupling means 48 will be extended sufficiently into at least a portion of the hollow tube-like core means 20 of the other one-hand dispensing means 10.
Thus, the two one-hand dispensing means 10 are adequately coupled together to form the second embodiment of the one-hand dispensing means 15. In this assembly, the second embodiment of the one-hand dispensing means 15 may be operated in the same manner as a two-hand dispensing means as covered in the aforementioned and cited U.S. patents, invented by the applicant.
In using the second embodiment of the one-hand dispensing means 15, note that after assembly with the coupling means 48 as aforementioned, a cylindrical flexible hand grip 22 is on each end of the assembly so that it can be operated the same as a two-hand dispensing means. However, in the arrangement the structure of the present invention pays out two parallel strips or sheets of plastics stretch film, usually each of narrow width, and permits the aforementioned "roping" effect of a plurality of strips.
The second embodiment of the one-hand dispensing means 15 makes the application of plastics stretch film 24 in the "roping" manner very simple. As the two strips of plastics stretch film 24 are payed out by peeling off of the rolls side by side, the two flexible hand grips 22 are periodically or intermittently switched or exchanged to the opposite hand, while on the extension 40 of the core means 20, and thus causing a twist or flap over of the two side by side sheets or strips of plastics stretch film 24. Thus, the "roping" effect is formed. This "roping" effect strengthens the binding and securing of the unit of load being handled.
The first and second embodiments of one-hand dispensing means, 10 and 15 respectively, for plastics stretch film 24 are ideal for narrow widths of the plastics stretch film 24. The overall short length of the one-hand dispensing means 10, required for the narrow widths of the plastics stretch film 24, results in a low cantilever stress on the wrist when stabilizing light weight materials and items, which is not possible with film dispensing means of the prior art.
It is to be noted that the first embodiment of the one-hand dispensing means 10 can also be used as a two-hand dispensing means. To do this the coupling means 48 is inserted into the hollow tube-like core means 20, as in preparing to set up the second embodiment of a one-hand dispensing means 15, but without adding the second one-hand dispensing means 10.
Then, to use it as a two-hand dispensing means, the operator or user uses one hand to grip the cylindrical flexible hand grip 22 and the other hand to grip the end of the coupling means 48 which protrudes from the hollow tube-like core means 20.
In using the one-hand dispensing means 10 with the coupling means 48 to dispense plastics stretch film 24 in a two-hand procedure it permits a narrow width of plastics stretch film to be used in binding and securing materials or items for movement or shipment. This economical use of the plastics stretch film 24 is useful when the unit package or load is small, or when the unit package or load requires a minimum of binding or securing for short distance movement, such as for intraplant movements.
The first and second embodiments of one-hand dispensing means, 10 and 15 respectively, for plastics stretch film 24 provide two means for using narrow width stretch film. There are numerous uses for the narrow width stretch film 24 that have economic and technical advantages over the use of wide width stretch film normally associated with the two-hand dispenser means of the prior art. The present invention provides the user those options.
It is to be noted further that in using the narrow width plastics stretch film, as provided by the present invention, the "stretch" can be increased by approximately 100% especially when using the second embodiment or the variation of the first embodiment mentioned hereinbefore.
It is also to be noted that the second embodiment of the one-hand dispenser means 15 for plastics stretch film 24 provides a convenient method for shipping pairs of the first embodiment of one-hand dispensing means 10. The first embodiment of the one-hand dispensing means 10, assembled in the form of the second embodiment of the dispensing means 15, is simply packaged that way in a package of two units or multiples thereof. The coupling means 48 stabilizes the two units for packaging.
It is also to be noted that the one-hand dispensing means 10 or 15 may also use the open end hand grip of the prior art, the closed end hand grip 22 of the prior art and illustrated in FIGS. 1, 2, and 3, or a preferred flange-type hand grip 52 shown in FIGS. 4 and 5 and described hereinafter. The use of the closed end hand grip 22 in FIGS. 1, 2, and 3 is for purposes of clarity in the illustration. The use of the preferred embodiment of the flange-type hand grip 52 operates the same as the closed end hand grip 22, but has additional advantages as described hereinafter.
The closed end hand grip 22, as used in the prior art, but used herein for initial illustration, has two distinct problems which the preferred embodiment of the flange-type hand grip 52 overcomes.
The first problem is that the turning or revolving of the core, such as core means 20, has a tendency to generate frictional heat at the closed end and cut through the closed end, thus then facing the same problems generated by the original prior art open end hand grip. The second problem is that the operator's hand and knuckles rubs on the edges of the roll of plastics stretch film on the core and causes fusing of and tears in the film, similar to problems in the prior art. The rubbing problem occurs regardless of whether the operator is using bare hands or gloved hands. The present invention overcomes these problems.
The flange-type hand grip 52 is of the same material as the closed end hand grip 22 and provides the same "feel", control, and braking action as aforementioned for the closed end hand grip 22. Both of the hand grip means 22 and 52 are monolithically formed. The flange-type hand grip 52 also has and provides the same clearance from the frontal face 42 of the roll of plastics stretch film 24. The flange-type hand grip 52 has substantially the same flexible characteristics as the hand grips 22, and varies in configuration as described hereinafter.
It is to be noted that a hand grip means is a component of the actual total structure of both the first and second embodiments of the dispensing means 10 and 15 for plastics stretch film 24.
The flange-type hand grip 52 consists of a body portion 54, and inboard flange 56, and an outboard inturned lip 58. The cooperation of these elements to form the component flange-type hand grip 52 for the total structure of a dispensing means 10 or 15 for plastics stretch film 24 is described hereinafter.
The inboard and outboard references hereinbefore for the flange-type hand grip 52 refer to the manner in which the component flange-type hand grip 52 is slideably and removably affixed to the end of the core means 20 in the final assembly for use. Inboard refers to the inward side toward the frontal face 42 of the roll of plastics stretch film 24. Outboard refers to the outside end of the extension 40 of the core means 20 away from the frontal face 42 of the roll of plastics stretch film 24 and is the end upon which the improved hand grip 52 is assembled.
The body portion 54, has a slight taper, approximately 1°, from the inboard or flange end to the outboard end. The body portion 54 is substantially cylindrical, except for the aforementioned slight taper, and is hollow or tube-like. The dimensional diameter of the body portion 54 is larger at the inboard end than at the outboard end to provide the taper. The slight taper provides a convenient snugness at the outboard end that is enough to prevent the hand grip 52 from dropping or falling off of the extension 40 of the core means 20 as the dispensing means 10 or 15 is lowered into packing or shipping boxes or cartons. Also, to prevent the hand grip 52 from dropping or falling off when being removed from the shipping boxes or cartons. It is to be understood, however, that a variation in the taper is within the scope and intent of this invention.
The inboard flange 56 is integral and monolithic with the body portion 54 and extends outwardly therefrom. The flange extends outwardly sufficiently to shield the frontal face 42 of the roll of plastics stretch film 24 from being rubbed by the operator's hand and knuckles as the roll of plastics stretch film 24 turns or revolves during application. The plane of the flange 56 is more or less perpendicular to the axis of the body portion 54.
The inturned lip 58 serves essentially the same purpose as the closed end 28 of the hand grip 22. The inturned lip 58 prevents the hand grip 52 from sliding inwardly on the extension 40 of the core means 20. Note that the outboard end 46 of the core means 20 will butt against the inturned lip 58 which prevents the hand grip 52 from sliding inwardly as aforementioned.
The inturned lip 58 is sufficiently large enough to also prevent the coupling means 48 from projecting from or escaping through the open end when two first embodiment dispensing means 10 are combined to form the second embodiment of a dispensing means 15.
The inturned lip 58 of the hand grip 52 is dimensionally thicker than the thickness of closed end 28 of the hand grip 22. This extra thickness provides for the necessary wear and tear due to the turning or revolving outboard end 46 of the core means 20 when plastics stretch film 24 is being applied to packaging from the roll. This eliminates the cutting out of the end as experienced in the prior art.
The inturned lip 58 has an inside diameter 60 such that the aperture opening is sufficiently small so that the coupling means 48 is also held captive within the interior of the core means 20 when used to convert two one-hand dispensing means 10 to a second embodiment of one-hand dispensing means 15.
It is to be noted also that an alternative to making the inturned lip 58 large enough to prevent the coupling means 48 from escaping, the thick inturned lip 58 may be made large enough to take the wear and tear of the outboard end 46 of the core means 20 and then close the balance of the outboard open end of the flange-type hand grip 52, similar to hand grip 22, to prevent the escape of the coupling means. Such an alternative is not shown, but is within the scope and intent of this invention.
An alternate method 62 of forming the inturned lip 58 is shown in FIG. 6. The modification 62 to the inturned lip 58 is a straight turning inwardly to form the lip. In the hand grip 52 the inturned lip 58 turns inward and then upward.
The one-hand dispenser means 10 may be operated by left or right handed persons without any modification of the present invention. When the one-hand dispenser means 10 is operated by the two-hand method of holding the coupling means 48 in one hand, as aforementioned, it is essentially a "one brake" hand wrapper instead of the "two brake" hand wrapper in the normal two-hand operation.
Regarding the aforementioned reference to light weight materials or items, such light weight items that require a steadying or stabilizing with the free hand until the initial binding or securing is completed are empty boxes, containers such as empty bottles and cans on trays or separators in multiple layers, boxes or bags of very light weight materials, and other similar items. Often the movement is an in-plant movement or short-haul transfer. The prior art of using string, various types of narrow tape, and other such methods has been most unsatisfactory. The present invention overcomes the problems.
Regarding the "roping" effect, mentioned hereinbefore, which is possible with the second embodiment of the one-hand dispensing means 15, the "roping" effect is particularly useful in overcoming problems encountered in binding and securing piled or stacked boxes. In ordinary binding and securing of boxes in the prior art, the boxes were often crushed. With the present invention, using the two one-hand dispensing means concurrently, the double bands can be applied at the corners of the pile or stack and then with the "roping" effect make the "X" or criss-cross and give the added strength without crushing the boxes.
The one-hand dispensing means 10 is also used to provide a preliminary stabilizing binding on pallet loads that are being moved to a position for subsequent machine wrapping of a binding and securing cover. Without the preliminary stabilizing binding, particularly on light weight materials or items, the machine operation often spills the load or knocks it askew.
It is to be understood that the inside diameter of aperture 60, specified hereinbefore as being small enough to prevent the passage therethrough of coupling means 48, may also be made large enough to permit the coupling means 48 to pass therethrough. Such a variation is within the scope and intent of this invention.
As can be readily understood from the foregoing description of the invention, the present structure can be configured in different modes to provide a one-hand dispensing means for plastics stretch film.
Accordingly, modifications and variations to which the invention is susceptible may be practiced without departing from the scope and intent of the appended claims. | The invention is an improved apparatus for the manual application of plastics stretch films to materials and items to be packaged and secured as a unit, or packaged and secured to a shipping and transporting device. The apparatus is particularly useful for one-hand operation where the other hand must be used to stabilize the materials or items being packaged or secured in some manner. The apparatus consists of an extended core for the supply of plastics stretch film and at least one tubular-like grip facility for the extended core. Said grip facility serving as a manual control device for the speed of paying out the plastics stretch film material, and as a manual facility for applying tension on the film during the course of applying it to materials and items being packaged or secured. Two one-hand devices may be combined by a simple shaft-like member for operation as a two-hand device. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a firing mechanism for a gun utilized to effect the perforation of a subterranean well casing or liner through the application of a fluid pressure force to the firing mechanism.
2. Description of the Prior Art
Perforating guns have long been employed to effect the perforation of a well casing or liner in the vicinity of a production zone and to produce fractures extending into such production zone. The popular perforating guns now uniformly employ the so-called "shaped charges", which are disposed in vertically and angularly spaced relationship relative to the casing axis so as to produce a large number of evenly spaced perforations with a single firing. Such shaped charges are generally ignited by a primer cord which contacts a primer end of each shaped charge container to detonate the charge contained within each such container.
The ignition of the primer cord is commonly accomplished by dropping a weight or bar on an impact actuated primer or detonator which is stationarily positioned immediately above the perforating gun housing and is operatively connected to the primer cord which extends downwardly through the perforating gun housing. The employment of a detonating bar dropped through a tubular conduit as a means for effecting the ignition and discharge of the perforating gun has encounttered difficulties in those wells wherein the well bore deviates substantially from the true vertical when passing through a particular production zone. The deviation may be sufficiently great that the fall speed of the detonating bar is substantially reduced, to the point that insufficient impact energy is imparted to the primer charge to effect its discharge. In other wells where it is necessary to employ a high-density kill fluid or the like, the existence of such fluid in the conduit bore, through which the the detonating bar is dropped, can very well reduce the speed of the detonating bar to an ineffective level. Debris collecting around the hammer can have the same effect. Any failure to detonate the primer charge obviously imposes a substantial cost and time penalty on the completion of the well.
It has previously been proposed that the actuation of the hammer to fire the primer charge be effected by fluid pressure forces establishing a differential between the fluid pressure existing in the tubing string carrying the perforating gun versus the fluid pressure existing in the annulus around such tubing string, but when utilizing such fluid pressures to effect the actuation of the hammer of the perforating gun, another factor must be taken into account, namely the desirability of perforating the well with the fluid pressure existing in the casing annulus adjacent the zone to be perforated being maintained at a relatively low level so that the perforating of the adjoining production formation is accomplished with the well in the so-called "underbalanced" condition. In other words, the anticipated fluid pressure of fluid from the perforated production zone should desirably be in substantially excess of the fluid pressure existing within the well casing at the moment that perforation is accomplished, so that flow from the peforated production zone can immediately commence with a substantial velocity and thus remove the debris naturally associated with the perforating operation from the perforations in the production formation.
Such underbalanced condition is commonly produced by suspending the perforating apparatus from a tubing-carried packer which is set at a position above the production zone to be perforated. A cross-over sub is then provided to divert the fluid transmitted by the tubing bore into the casing annulus below the packer for the reason that it is much easier to reduce the fluid pressure existing in the annulus adjacent the production zone to be perforated by a swabbing operation in the tubing string. The annulus fluid pressure existing above the packer is transmitted to the firing mechanism for the perforating gun by an axially extending fluid passage provided in the packer. Thus an increase in annulus pressure accompanied by a simultaneous decrease in tubing pressure will produce a pressure differential sufficient to cause the fluid pressure actuation of the hammer of the firing mechanism, while at the same time producing an underbalanced condition in the casing annulus adjacent the production zone to be perforated. A fluid pressure actuated firing mechanism for a perforating gun of this general type is disclosed and claimed in co-pending application, Ser. No. 593,396, filed Mar. 26, 1984, and assigned to the Assignee of the present invention now U.S. Pat. No. 4,594,335.
A fluid pressure actuating mechanism for a perforating gun which is operable solely by changes in the selected fluid pressure would obviously provide a simplified system for effecting the fluid pressure actuation of a well perforating gun.
SUMMARY OF THE INVENTION
In a preferred format of the invention, The invention provides a perforating gun assembly comprising a tubular work string having a packer mounted at the end thereof; a fluid pressure actuated firing means mounted in a first housing depending from the packer, and the perforating gun comprising the plurality of shaped charges mounted in a second housing depending from the first housing. The first housing contains a fixedly mounted primer charge and conventional means, such as a primer cord, is employed for transmitting the detonating energy of the primer charge to the shaped charges contained in the lower second housing. The first housing further defines a fluid pressure chamber above the primer charge within which a hammer is slidably and sealably mounted. The top end of the fluid pressure chamber, which would normally be in communication with the bore of the packer and the supporting tubing string is closed at its upper end by a frangible barrier at the location below the casing seal elements of the packer. In a preferred embodiment of the invention, radial ports are provided above the frangible barrier to place the bore of the tubing string in fluid communication with the casing annulus below the packer. Thus the fluid pressure in the casing annulus adjacent to the production zone to be perforated is determined by the tubing pressure.
Two fluid conduits are provided at opposite ends of the fluid pressure chamber, hence above and below the hammer, to provide communication between the ends of the fluid pressure chamber and the casing annulus located below the packer. The fluid conduit for the upper end of the fluid pressure chamber includes one or more check valves which function to permit flow of pressured fluid only in the direction into the fluid pressure chamber. A releasable latching mechanism secures the hammer in an intermediate position between the two fluid pressure conduits and in an elevated position relative to the primer charge.
Accordingly, when the fluid pressure in the tubing string is increased, the fluid pressure above and below the hammer is correspondingly increased and no movement of the hammer is produced. The latching mechanism is constructed to to retain the hammer in such intermediate, inoperative position until a sufficient fluid pressure differential exists above the hammer to insure that it will be driven downwardly with sufficient force to effect the detonation of the primary charge.
The necessary fluid pressure differential to effect the release of the latching mechanism and the actuation of the hammer is derived by then reducing the fluid pressure in the tubing string or in the casing annulus above the packer, to the level desired for effecting the perforation of the well in an underbalanced condition. Such reduction in fluid pressure concurrently effects a reduction in the fluid pressure below the hammer, but the fluid pressure above the hammer is trapped due to the provision of the check valves in the fluid supply conduit. Thus, as the tubing pressure is reduced, the fluid pressure differential above the hammer is increased until it reached a level to cause the disengagement of the releasable latching means and the driving of the hammer downwardly into impact engagement with the primer charge. The detonation of the primer charge effects the ignition of the primer cord, and the primer cord in turn effects the detonation of the shaped charges disposed in the second housing.
The apparatus embodying this invention has the further advantage of providing a backup mechanical actuation of the firing mechanism in the event that the fluid pressure actuation of the hammer does not, for any reason, produce the detonation of the primer charge. It will be recalled that the upper end of the fluid pressure chamber is defined by a frangible barrier. The dropping of a detonating bar through the tubing string will effect the shattering of this frangible barrier and the bar will impact on the hammer and hence impart impact energy to the primer charge sufficient to effect its detonation. Thus, the well operator has a second chance of effecting the firing of the perforating gun without removing any of the equipment from the well.
In the unlikely event that neither the fluid pressure actuation nor the mechanical actuation of the firing mechanism is successful, the firing mechanism embodying this invention has the further advantage in that it provides utmost safety to the operator when the entire perforating gun and firing mechanism is removed from the well for repair. The shattering of the frangible barrier forming the upper end of the fluid pressure chamber insures that no fluid pressure differential can exist across the hammer and thus, the danger of the hammer being subjected to fluid pressure forces to fire the primer charge as the gun is being removed from the well, is eliminated.
Further advantages of the invention will be readily apparent to those skilled in the art from the following detailed description, taken in conjunction with the annexed sheets of drawings, on which is shown a preferred embodiment of the invention.
BRIEF DESCRIPTION OF DRAWINGS
FIGS. 1A, 1B, 1C, 1D, and 1E collectively represent a vertical, sectional view of a fluid pressure actuated firing mechanism for a subterranean well perforating gun.
FIG. 2 constitutes a sectional view taken on the plane 2--2 of FIG. 1B.
FIGS. 3A and 3B are views respectively similar to FIGS. 1C and 1D but showing the hammer position after firing.
FIG. 4 is a schematic elevational view of the apparatus of this invention supported in a well by a packer.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, there is shown a fluid actuated firing mechanism 1 comprising a tubular housing assembly 2 which is normally connected at its upper end to a conventional packer (not shown) which is set in the well casing (not shown) at a location above the production zone to be perforated, and at its lower end is connected to any conventional form of perforating gun 20, of which only the top portion thereof is shown. The tubular housing assembly 2 comprises at its upper end a barrier mounting sub 3 having internal threads 3a for connection to the lower portion of a tubular conduit. At its lower end, the barrier mounting sub 3 is provided with internal threads 3b for connection to the external threads 4a of a connecting sub 4. An O-ring 3c seals this threaded connection and a set screw 4b prevents rotation of the threads.
The lower end of connecting sub 4 is provided with external threads 4c and an O-ring 4d to provide a sealed, threaded connection to a length of space-out tubing 5. The lower end of tubing 5 is provided with internal threads 5a for effecting a connection with the upper end of a detonating bar guide sub 6. An O-ring 6a seals this threaded connection and a set screw 5b prevents disengagement of the threads. The lower end of the guide sub 6 is provided with internal threads 6b for effecting a threaded connection to the upper end of a fluid pressure charging sub 7 within which check valves 9 are mounted, in a manner to be hereinafter described. O-ring 7a and set screw 7b secure this threaded connection. At the lower end of charging sub 7, internal threads 7k effect a threaded connection to a hollow hammer mounting housing 10 which is sealed by O-rings 7m. Housing 10 is provided at its lower end with external threads 10k and O-rings 10m for effecting a sealed connection to a booster chamber sub 11. The lower portion of booster chamber sub 11 is provided with internal threads 11a for effecting a connection to the top of a conventional perforating gun 20.
As is well-known to those skilled in the art, the entire assemblage heretofore described is normally mounted in depending relationship to a packer 60 (FIG. 4) and the packer is set by a conventional setting mechanism 61 at a location in the well casing c so as to position the perforating gun adjacent the production formation to be perforated. The packer is carried into the well on a tubing string or may be stabbed into a polished bore receptacle, by wire line, or the like, and the bore of the tubing string communicates with the bore of the packer and in turn with the bore of the barrier sub 3.
Barrier sub 3 is provided with a plurality of radial ports 3d around its circumference. Immediately below the radial ports 3d, barrier sub 3 defines a downwardly facing surface 3e. A frangible barrier 8, which is preferably formed of glass or frangible ceramic is secured between the downwardly facing shoulder 3e and the top end of the connecting sub 4. An O-ring 3f provides a seal between the barrier 8 and the barrier sub 3. Thus, any pressured fluids supplied through the tubing string will enter only the top portions of the barrier sub 3 and then be diverted through the radial ports 3d into the annulus between the tubular assembly 2 and the well casing.
Between the barrier sub 3 and the internal bore of the hammer mounting housing 10, a fluid pressure chamber PC is defined. Pressured fluid is supplied to this fluid pressure chamber through the utilization of one or more check valves 9 mounted in the charging sub 7. In the preferred embodiment of the invention, charging sub 7 is provided with an axially extending fluid passage 7c communicating with a horizontally extending fluid passage 7d which projects through the wall of the charging sub 7 to communicate with the casing annulus. (FIG. 2) An identical check valve 9 is mounted in each of the fluid passages 7d and 7c and comprises a plug element 9a threadably secured in the end of the respective fluid passage and supporting a spring 9b which urges a valving head 9d, having an elastomeric sealing surface 9e, into engagement with a shoulder 7e, in the case of fluid passage 7d, and a shoulder 7f in the case of fluid passage 7c. A radial port 7g communicates with the fluid passage 7c at a position which is normally blocked by the check valve 9. In the positions of the check valves 9 illustrated in FIG. 1B and FIG. 2, the valves are in their open or pressurized position, thus permitting unrestricted fluid flow from the casing annulus through the fluid passage 7d, thence into the fluid passage 7c and thence into the port 7g to supply pressured fluid to the fluid pressure chamber PC. When the fluid pressure in the pressure chamber PC equals the casing annulus pressure, both of the check valves 9 will close and thus the pressured fluid in fluid pressure chamber PC will be trapped and will remain at its maximum value. The two check valves 9 are employed in series relationship to better insure that the trapped fluid pressure will not be inadvertently lost through leakage through one of the valves.
In order to prevent a build-up of pressure within the pressure chamber PC during the insertion of the perforating gun 20 and firing mechanism 1 into the well, a pressure relief bleed aperture 4e is provided in the wall of connecting sub 4. Aperture 4e is straddled on its exterior by two axially spaced seals 4f, and these seals engage a seal bore surface PB such as the seal bore extension commonly associated with a downhole mounted packer. Thus, when the perforating gun 20 and the firing mechanism 1 are positioned in the seal bore extension preliminary to firing of the perforating gun 20, the pressure bleed opening 4e is closed and the pressure within the fluid pressure chamber PC is determined by the pressured fluid supplied from the casing annulus below the packer through fluid passages 7c and 7d. This may require movement of the tubing string relative to the set packer which is accomplished in any conventional manner.
As previously mentioned, the lower end of the charging sub 7 is provided with external threads 7k for engagement with external threads provided on the top of a hollow hammer housing 10 which contains the hydraulic firing mechanism. A pair of O-rings 7m effects the sealing of the threaded connection. The hollow body element 10 defines a central bore 10b which is in communication with the fluid pressure chamber PC and the lower portion of bore 10b is slightly enlarged as shown at 10c.
A primer mounting sleeve 30 is sealably inserted within the bottom end of the hollow housing 10 by internal threads 10d and O-ring seal elements 30a provided on the exterior of the primer mounting sleeve 30. A hollow plug 31 is in turn threadably mounted in the bottom of the primer mounting sleeve 30 by threads 31a and the threaded connection is sealed by an O-ring 31b. Plug 31 holds an impact detonable primer element 32 in snug engagement with a downwardly facing shoulder 30b formed on the interior of the sleeve 30. O-ring 30e seals this abutting connection and an O-ring 32a seals the bottom of the primer 32 against the upwardly facing end surface of the plug 31.
Plug 31 is provided with an internal bore 31c and a booster charge 33 is mounted in such bore and is conventionally connected to a short length of primer cord 34 extending downwardly through the bore of the connecting sub 11 and terminating in a second booster charge 35. Booster charge 35 is spaced immediately above a booster charge 36 conventionally provided in a coupling 25 mounted on the top end of the perforating gun 20 and providing an operative connection with the primer cord 26 which extends through the gun to ignite all of the shaped charges 21 mounted therein.
Primer 32 is normally detonated by the pointed end 40a of a fluid pressure actuated hammer 40. The hammer has an enlarged top end portion 41 which slidably engages the bore 45b of the top ring portion 45a of a collet 45.
The flexible arm portions 45c of the collet 45 extend downwardly in parallel relationship to the hammer 40 and are provided with a thickened portion 45d along the length thereof which defines an inwardly projecting latching surface 45e which cooperates with a similarly inclined downward facing surface 42 provided on the hammer 40 so as to retain the hammer 40 in an elevated position relative to the primer 32. Thus, sufficient fluid pressure force must be applied to the hammer 40 to cause the inclined surfaces 42 to cam the collet arms 45c outwardly to release the hammer to travel downwardly and impact primer 32. It will be noted that the bottom end of the collet arms 45c terminate in a solid ring 45g.
To prevent any premature movements of the hammer 40 toward the primer charge 32, a locking sleeve piston 46 is provided which is slidably and sealably mounted within the bore 10b of housing 10. Locking sleeve piston 46 is normally positioned adjacent an outwardly projecting rib 45f formed on each of the collet arms 45c and thus positively prevents any outward displacement of the collet arms 45c. Locking sleeve piston 46 is secured in its locking position by a shear screw 46c which traverses the wall of the housing 10 and engages an annular groove 46d provided in such locking sleeve 46.
A sealing sleeve 47 is mounted in the housing bore 10c immediately below the locking sleeve piston 46 and is sealably engaged with such bore at its upper end by an O-ring 47a. The lower end 47b of the sealing sleeve is of reduced diameter and mounts an O-ring seal 47c which sealably engages the lower portion of the hammer 40. Thus, fluid pressure existing in the overlying fluid pressure chamber PC is applied to the hammer 40 to exert a downward force thereon. The lower end 47b of the sealing sleeve 47 is threadably engaged with internal threads 30c formed on the upper end of primer mounting sleeve 30.
A fluid passage 10e is provided in the wall of housing 10 and permits fluid pressure from the casing annulus surrounding the housing assembly 2 to be applied to the lower portions of the hammer 40 through a radial port 30d provided in the primer mounting sleeve 30. Thus, the upper portion 41 of hammer 40 is exposed to the fluid pressure existing in the fluid pressure chamber PC, while the lower portion of hammer 40 is exposed to the fluid pressure existing in the casing annulus below the packer (not shown).
Additionally, a radial port 10f (FIG. 1C) is provided in the hollow housing 10 at a position intermediate O-ring seals 46a and 46b provided on the exterior of the locking sleeve piston 46. These seals contact the bore walls 10b and 10c respectively at different diameters, and hence, when the fluid pressure in the fluid pressure chamber PC exceeds the fluid pressure existing in the annulus surrounding the tubular housing assembly 2, an upward force will be exerted on the locking piston 46. When such force reaches a predetermined level, corresponding to the desired amount of pressure differential to be exerted on the hammer 40, the shear pin 46c is sheared and the locking sleeve piston 46 moves upwardly to the position illustrated in FIGS. 3A and 3B, thus permitting the hammer 40 to cam the collet arms 45c outwardly and drive down into impact engagement with the primer 32. Locking sleeve piston 46 is retained in such released position by an expandable C-ring 45h carried on the ring portion 45a of collet 45.
The operation of the aforedescribed fluid pressure actuated firing mechanism will be readily apparent to those skilled in the art. The fluid pressure in the casing annulus surrounding the housing assembly 2 is first increased. If the aforedescribed firing mechanism and perforating gun are mounted below a packer, as is customary, the frangible barrier 8 and the radial ports 3d will be located below the seal elements of such packer and hence the tubing string pressure will be supplied to the casing annulus below the packing. Such pressured fluid enters the fluid pressure chamber PC through the unidirectional check valves 9 provided in the fluid passages 7d and 7c and raises the fluid pressure in such fluid pressure chamber to the level existing in the casing annulus below the packer. The tubing pressure may then be decreased by bleeding off the pressure. A further decrease, if desired, can be obtained by swabbing operations in the tubing string. In any event, the fluid pressure in the casing annulus surrounding the housing assembly 2 will be substantially reduced below the level of the pressured fluid trapped within the fluid pressure chamber PC. When the fluid pressure differential across the hammer 40 reaches a desired level, the locking sleeve piston 46 is shifted by such fluid pressure differential, shearing the shear pin 46c. The hammer 40 can then cam the collet arms 45c outwardly and drive down into impact engagement with the primer 32 under the force of the differential fluid pressure.
The detonation of primer 32 effects the detonation of the booster charge 33 and in turn the ignition of the intermediate primer cord 34 which travels down the primer cord 34 to detonate the booster charge 35. Detonation of booster charge 35 will effect the detonation of the booster charge 36 contained within the upper end of the perforating gun 20, thus effecting the detonation of the primer cord 26 extending through the perforating gun 20 to detonate each of the shaped charges 21 mounted therein.
Another feature of this invention is notable in the event the application of the differential fluid pressure to the hammer 40 fails to effect the detonation of the primer 32. A second impact blow may be applied to the primer 32 through the simple expedient of dropping a detonating bar (not shown) through the tubing string which will travel downwardly and impact on the upper end 43 of the hammer 40 which projects above the bore 10b of the hollow housing 10 sufficiently to be engaged by such detonating bar. Since many primers will discharge after being subjected to a cumulative amount of impact force, such additional impact force applied to the hammer 32 may be successful in effecting its detonation, thus eliminating the need for removal of the perforating gun and firing mechanism from the well. In any event, it is desirable that the frangible barrier 8 be broken by a detonating bar or a wireline tool prior to removal of the firing mechanism from the well in order to remove any fluid pressure from the fluid pressure chamber PC which might cause the inadvertent firing of the primer charge 32 as the firing mechanism is being removed from the well. Thus, the removal of the firing mechanism and perforating gun may be accomplished with an added degree of safety not previously available in prior art mechanism.
The aforedescribed hydraulic firing mechanism may be employed to effect the firing of a fluid pressure actuated firing mechanism of a redundant firing mechanism, incorporating both mechanical and a fluid pressure actuated firing mechanism and separate primers associated therewith. A redundant firing mechanism of this type is described and claimed in my co-pending application, Ser. No.: 743,044, filed concurrently herewith.
It will be appreciated that, while a preferred embodiment utilizes means to direct fluid flow from the tubing into the casing annulus below the packer, such means, including value components, can be easily modified to direct fluid flow from the casing annulus above the packer into the tubing string below the packer.
Although the invention has been described in terms of specified embodiments which are set forth in detail, it should be understood that this is by illustration only and that the invention is not necessarily limited thereto, since alternative embodiments and operating techniques will become apparent to those skilled in the art in view of the disclosure. Accordingly, modifications are contemplated which can be made without departing from the spirit of the described invention. | A compressed fluid pressure actuated firing mechanism for a well perforating gun comprises a hollow housing assembly defining a mounting for a primer, a hammer releasably secured above the primer for movement towards the primer, and a fluid pressure chamber associated with the hammer for effecting a compressed fluid pressure force on the latching mechanism for the hammer and on the hammer to move it into impact engagement with the primer. The fluid pressure applied to the hammer is produced by permitting a selected fluid pressure surrounding the fluid pressure chamber to be forced into the fluid pressure chamber through at least one unidirectional check valve, thus compressing the fluid pressure within the fluid pressure chamber. The upper portions of the hammer are in contact with this compressed fluid pressure and the lower portions of the hammer are in contact with the selected fluid pressure. Thus, a subsequent decrease in the selected fluid pressure allows the trapped fluid pressure to expand sufficiently to effect the release and firing movement of the hammer. | 4 |
BACKGROUND
[0001] 1. Technical Field
[0002] The disclosure relates to an electronic device with a movable display.
[0003] 2. Description of Related Art
[0004] Usually, displays of electronic devices are movable for convenient operation and to save space. For example, a clamshell mobile phone generally has a main body and a display slidably mounted to the main body. The displays are pushed relative to the main body by fingers of the operator abutting against the displays. However, the displays are easily abraded, which is unsightly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, all the views are schematic, and like reference numerals designate corresponding parts throughout the several views.
[0006] FIG. 1 is an exploded, isometric view of an embodiment of an electronic device, wherein the electronic device includes a slide apparatus and an operation apparatus.
[0007] FIG. 2 is an exploded, isometric view of the slide apparatus of FIG. 1 .
[0008] FIG. 3 is an exploded, isometric view of the operation apparatus of FIG. 1 .
[0009] FIG. 4 is a partially assembled, isometric view of FIG. 1 .
[0010] FIG. 5 is an assembled, isometric view of FIG. 1 .
[0011] FIG. 6 is a cross-sectional view of FIG. 5 , taken along the line of VI-VI.
[0012] FIG. 7-8 are similar to FIG. 6 , but showing two different states of the electronic device of FIG. 1 .
DETAILED DESCRIPTION
[0013] The disclosure, including the accompanying drawings, is illustrated by way of examples and not by way of limitation. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean “at least one.”
[0014] FIG. 1 shows an electronic device 100 includes a display 20 , a base 40 , a slide apparatus 60 , and an operation apparatus 80 .
[0015] A bottom surface of the display 20 defines a long receiving slot 24 extending along a lengthwise direction of the display 20 . The receiving slot 24 is located in a side of a front end of the display 20 . A positioning bar 26 protrudes down from a middle of the bottom surface of the display 20 , and extends along a widthwise direction of the display 20 .
[0016] A top surface of the base 40 defines a rectangular receiving space 422 . The receiving space 422 is located in a side of a front end of the base 40 . The side of the base 40 defines a guiding slot 424 communicating with the receiving space 422 . The base 40 defines two opposite guiding holes 426 in a junction of the receiving space 422 and the guiding slot 424 . Two spaced stopping bars 427 protrude up from a middle of the top surface of the base 40 , and are arranged in a fore-and-aft direction of the base 40 .
[0017] The slide apparatus 60 includes a rack 61 mounted in the receiving slot 24 of the display 20 and a transmission mechanism 63 .
[0018] FIG. 2 shows the transmission mechanism 63 includes a bracket 631 , a gear 633 , and two resilient assemblies 635 .
[0019] The bracket 631 is substantially rectangular, and includes a top surface 6311 and a side surface 6312 extending down from a side of the top surface 6311 . A middle of the side surface 6312 defines a circular recess 6313 . The recess 6313 extends through the top surface 6311 . Two opposite ends of the side surface 6312 defines two opposite rotation holes 6315 adjacent to the recess 6313 . A shaft 6316 perpendicularly extends out from a middle of an inner wall of the recess 6313 opposite to the side surface 6312 . An axis of the shaft 6316 is coaxial with an axis of the recess 6313 .
[0020] A cam-shaped protrusion 6331 protrudes out from a middle of a side of the gear 633 . The protrusion 6331 includes a first portion aligning with a middle of the gear 633 and a second portion protruding out from a side of the first portion. The first portion is greater than the second portion in size. The middle of the gear 633 axially defines a shaft hole 6332 extending through the first portion of the protrusion 6331 . The gear 633 defines two opposite connecting holes 6335 at two opposite sides of the protrusion 6331 . A pole 6336 protrudes out from the second portion of the protrusion 6331 . An axis of the pole 6336 deviates from the axis of the gear 633 .
[0021] Each resilient assembly 635 includes a rotating pole 6351 , a first resilient member 6352 , and a substantially L-shaped connecting member 6354 . An end of the rotating pole 6351 radially defines a through hole 6358 . The connecting member 6354 includes a pivot 6355 , a connecting pole 6356 perpendicularly extending out from an end of the pivot 6355 , and a shrink-ring 6357 mounted on an end of the connecting pole 6356 and adjacent to the pivot 6355 . In the embodiment, the first resilient member 6352 is a coil spring.
[0022] FIG. 3 shows the operation apparatus 80 includes an operation member 82 , two second resilient members 84 , and an adjusting member 86 .
[0023] The operation member 82 includes a rectangular sliding plate 821 , the sliding plate 821 includes an inner side surface 820 . A connecting shaft 822 perpendicularly protrudes out from a middle of an upper side of the inner side surface 820 . Two opposite tabs 823 protrude out from the inner side surface 820 , and are located at two opposite sides of the connecting shaft 822 . Two pieces 825 protrude out from a middle of the inner side surface 820 , and adjacent to the tabs 823 . Two guiding poles 826 extend from the pieces 825 away from each other. Each guiding pole 826 is spaced and parallel to the sliding plate 821 . A plurality of skid-proof bars 827 protrudes out from an outer side surface of the sliding plate 821 opposite to the inner side surface 820 (shown in FIG. 4 ).
[0024] In the embodiment, each second resilient member 84 is a coil spring.
[0025] The adjusting member 86 is substantially triangular and includes a substantially C-shaped rotation portion 862 , two connecting pieces 864 slantingly extending down from two opposite distal ends of the rotation portion 862 and away from each other, and two hooks 865 formed on distal ends of the connecting pieces 864 . The hooks 865 extend toward each other.
[0026] FIGS. 4 and 5 show that in assembly of the electronic device 100 , the shaft 6316 of the bracket 631 is inserted in the shaft hole 6332 of the gear 633 from a side surface of the gear 633 opposite to the protrusion 6331 . The gear 633 is received in the recess 6313 , and a portion of gear 633 is exposed out of the top surface 6311 of the bracket 631 . The first resilient members 6352 fit about the connecting poles 6356 of the connecting members 6354 , distal ends of the connecting poles 6356 are inserted into the through holes 6358 of the rotating poles 6351 . The pivots 6355 of the connecting members 6354 are pivotably inserted into the connecting holes 6335 of the gear 633 .
[0027] The rotating poles 6351 are pivotably inserted into the rotation holes 6315 of the bracket 631 . Thus, each first resilient member 6352 is sandwiched between the shrink-ring 6357 and the corresponding rotating pole 6351 .
[0028] In assembly of the operation apparatus 80 , the second resilient members 84 are fitted about the guiding poles 826 of the operation member 82 . The rotation portion 862 of the adjusting member 86 is fitted about the connecting shaft 822 of the operation member 82 .
[0029] The transmission mechanism 63 is received in the receiving space 422 of the base 40 , the pole 6336 is received in the guiding slot 424 of the base 40 , and the portion of gear 633 is exposed out of the top surface of the base 40 . The operation apparatus 80 is received in the guiding slot 424 of the base 40 , and distal ends of the guiding poles 826 are inserted into the guiding holes 426 of the base 40 . The second resilient members 84 are sandwiched between the pieces 825 and the base 40 . The pole 6336 of the gear 633 is located between the hooks 865 of the adjusting member 86 . The display 20 is covered on the base 40 , to allow the rack 61 to engage with the gear 633 . The positioning bar 26 is stopped between the stopping bars 427 of the base 40 .
[0030] FIGS. 6-8 show that in use, the skid-proof bars 827 of the operation member 82 is pushed forward, to slide the sliding plate 821 forward along the guiding slot 424 . The guiding poles 826 slide forward along the guiding holes 426 . The second resilient member 6352 positioned at the front of the operation member 82 is pressed, to be deformed. The pole 6336 is latched in the hook 865 and positioned at a rear of the adjusting member 86 . The pole 6336 is rotated up about the shaft 6316 , to pivot the gear 633 clockwise. The gear 633 drives the rack 24 to move forward, to slide the display 20 forward relative to the base 40 . The pivots 6355 pivot in the connecting holes 6335 of the gear 633 , the rotating poles 6351 pivot in the rotation holes 6315 of the bracket 631 , and the connecting poles 6356 pivot in the through holes 6358 of the rotating poles 6351 . The rotating poles 6351 and the corresponding shrink-rings 6357 press first resilient members 6352 until the connecting poles 6356 are rotated to be in the same horizontal line. The operation member 82 is further pushed forward, to allow the connecting poles 6356 to misalign, and the adjusting member 86 is blocked by the corresponding tab 823 . The first resilient members 6352 are restored to bias the connecting members 6354 to slide away from the corresponding rotating poles 6351 . The connecting members 6354 drive the gear 633 to pivot clockwise. The gear 633 further drives the rack 24 to move forward, until the positioning bar 26 of the display 20 is blocked by the stopping bar 427 positioned on the front of the base 40 . The operation member 82 is released, the second resilient member 84 positioned at the front of the operation member 82 is restored to bias the sliding plate 821 back, and the adjusting member 86 is pivoted back. The pole 6336 of the gear 633 is received in the hook 865 positioned at a front of the adjusting member 86 .
[0031] When the display 20 needs to be closed, the skid-proof bars 827 are pulled rearward, to slide the sliding plate 821 rearward along the guiding slot 424 . The guiding poles 826 slide rearward along the guiding holes 426 . The second resilient member 6352 positioned at the rear of the operation member 82 is pressed, to be deformed. The pole 6336 is rotated up about the shaft 6316 , to pivot the gear 633 anticlockwise. The gear 633 drives the rack 24 to move rearward. The display 20 is slid rearward relative to the base 40 . The pivots 6355 pivot in the connecting holes 6335 of the gear 633 , the rotating poles 6351 pivot in the rotation holes 6315 of the bracket 631 , and the connecting poles 6356 pivot in the through holes 6358 of the rotating poles 6351 . The rotating poles 6351 and the corresponding shrink-rings 6357 press the first resilient members 6352 , until the connecting poles 6356 are rotated to be in the same horizontal line. The operation member 82 is further pulled rearward, to allow the connecting poles 6356 to misalign, and the adjusting member 86 is blocked by the corresponding tab 823 .
[0032] The first resilient members 6352 are restored to bias the connecting members 6354 to slide away from the corresponding rotating poles 6351 , to drive the gear 633 to pivot anticlockwise. The gear 633 further drives the rack 24 to move rearward, until the positioning bar 26 is blocked by the stopping bar 427 positioned on the rear of the base 40 . The operation member 82 is released, the second resilient member 84 positioned at the rear of the operation member 82 is restored to bias the sliding plate 821 back, and the adjusting member 86 is pivoted back. The display 20 is fully closed on the base 40 .
[0033] It is to be understood, however, that even though numerous characteristics and advantages of certain embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in the matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. | An electronic device includes a base, a display slidably covering the base, a slide apparatus installed between the base and the display, and an operation apparatus. The slide apparatus includes a rack mounted to the display, a gear pivotably installed in the base, and a pole protruding out from the gear. The operation apparatus includes an operation member slidably installed on the base and an adjusting member rotatably connected between the operation member and the pole. The rack is engaged with the gear. An axis of the pole deviates from an axis of the gear. The operation member is slid to drive the adjusting member to rotate the gear. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to a marine engine and drive unit having a superior configuration enabling the trimming and tilting adjustment of the drive unit without movement of the engine, including a low profile, an aftwardly extending center of gravity and improved silencing, and enabling the tilting and trimming adjustment of the drive unit whereby the center of gravity of the propulsion unit is kept of the marine craft to improve trim.
Conventional outboard motors have a generally linear orientation due to the direct connection of the crankshaft and driveshaft. The pistons of a conventional outboard motor are typically horizontally displaced about a vertically oriented crankshaft. This linear drive orientation causes the center of gravity of the conventional outboard motor to be located relatively high and relatively close to the transom of the boat onto which it is attached.
In addition, and particularly due to the shorter configuration resulting from a linear drive arrangement, a relatively short exhaust path present in conventional outboard motors increases the noisiness of the engine and does not permit optimum tuning for the best performance. This is particularly true in the case of a two cycle engine.
In conventional units, since the points of attachment of the outboard motor to the boat is primarily aft of the transom, the conventional outboard motor has to be more limited in its range of movement to accommodate space restrictions which may be encountered for different types of boats. Conversely, boats utilizing conventional outboard motors must have large motor wells to accommodate an array of different outboard motors, each having an intrusive tilt characteristic.
One way to mitigate the unwanted attributes described above is with a configuration known as an inboard/outdrive marine unit. However, the inboard/outdrive requires a hole to be cut in the transom and a special support for the engine which typically lies near the base of the hull. Such a solution is not a solution for outboard motors, but in reality an entirely different type of marine propulsion unit.
SUMMARY OF THE INVENTION
A marine propulsion unit, for mounting on the transom of a boat, has a horizontally oriented input shaft and has a lower drive unit which is angularly tiltable in the vertical plane without movement of the engine. The configuration enables the location of the driveshaft housing and lower unit at a point further aft of the transom to keep the marine propulsion unit's center of gravity in a more aftward position, enabling an extended length exhaust system, better control and handling of the exhaust, increased torque, and an increasing overall engine efficiency. The low profile of the marine propulsion unit coupled with its far forward pivot point requires a smaller motor well space and increased visibility in the direction aft of the boat.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the relative location of a conventional marine propulsion unit with respect to a boat;
FIG. 2 illustrates the relative location of the marine propulsion unit of the present invention with respect to a boat;
FIG. 3 is a side cross sectional view of the marine propulsion unit of the present invention in its normal running position;
FIG. 4 is a top sectional view of the marine propulsion unit illustrated in FIG. 3; and
FIG. 5 is a section taken along line 5--5 of FIG. 4.
FIG. 6 is a side view of the marine propulsion unit of FIGS. 3 and 4 showing the unit tilted up.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a standard propulsion unit 11 is shown in relationship to a boat 13. Marine propulsion unit 11, also known as an outboard motor, has a power head portion 15, and a drive unit including a driveshaft portion 17, and a lower unit portion 19, including propeller 21. The power head 11 is disposed above the driveshaft housing 17 and partially over the boat's transom, whose position is generally designated by the numeral 23.
In FIG. 1, the weights and centers of gravity of the conventional propulsion unit 11 and boat 13 are shown in schematic form. A vertical weight vector line W 1 on boat 13 defines the weight of boat 13 through its center of gravity, designated by a small circle along the length of vertical weight vector line W 1 , the center of gravity labeled G 1 . Conventional marine propulsion unit 11 has a vertical weight vector line W 2 and a center of gravity indicated by a small circle along the length of vertical weight vector line W 2 , center of gravity G 2 . On boat 13, a vertical V 0 extends through a point M 0 and forms the distance L 1 , which is the horizontal distance between V 0 and W 1 and L 2 representing the horizontal distance between V 0 and W 2 . M 0 is the central moment point selected for the summation of forces acting on boat 13. M 0 is the point about which forces acting on boat 13 are considered to be centered. These forces include the buoyancy force due to the water displaced by the aft portion of boat 13, and the drag forces due to the resistance of forward motion. The resultant force on the hull of boat 13 is labeled R 1 .
On lower unit 21 of conventional propulsion unit 11 is a point 25 in this case in the vicinity of a propeller shaft (to be shown later). From center line 25 a pair of vectors extend in the forward direction with respect to boat 13. Vector 27 represents the forward velocity of boat 13 as it travels through the water. Vector line 29 represents the angle of thrust of propeller 21. The angle formed between these two vectors is labeled "theta," and is the angle of deviation of the thrust direction 29 from the direction of travel 27.
The greater the angle of deviation, or theta, the greater the inefficiency of operation of marine propulsion unit 11. The angle theta represents a portion of the energy which is spent holding boat 13 in trim, rather than providing energy for forward travel. The angle of deviation is large because the center of gravity G 2 of conventional marine propulsion unit 11 is located high and close to transom 23. Center of gravity G 2 of marine propulsion unit 11 is not located sufficiently aft of boat 13 to provide the required weighted balancing force against point M 0 to enable boat 13 to naturally achieve a state of trim. As a result, thrust vector 29 is oriented in a somewhat downward position to compensate for the lack of weighted force. Note the somewhat elevated direction in which resultant R 1 is directed.
Referring to FIG. 2, the marine propulsion unit 31 of the present invention is similarly illustrated with respect to a boat 13. As in the case of a conventional marine propulsion unit 11, marine propulsion unit 31 has a power head 15 and driveshaft housing 17, a lower unit 19, and a propeller 21. Marine propulsion unit 31 also has a center of gravity G 2 on a weight vector W 2 . All of the quantities for boat 13 and for the centering of moments about M 0 are the same as those for FIG. 1. Note that center of gravity G 2 is located further aft and somewhat lower with respect to transom 23. Note that the overall height of marine propulsion unit 31 of the present invention is somewhat lower with respect to transom 23 than was the case for the conventional marine propulsion unit 11 of FIG. 1. Note the distance L 2 between weight vector line W 2 of marine propulsion unit 31 and vertical V 0 . The positioning further aft of the center of gravity G 2 provides a more natural force for enabling boat 13 to achieve trimming orientation. Note that angle theta between direction of travel vector line 27 and thrust vector line 29 is much smaller for FIG. 2 than was the case for FIG. 1. The configuration of marine propulsion unit 31 of FIG. 2 enables less energy to be spent for the achievement of trimming position enabling more energy to be utilized in the forward movement of boat 13. This indicates that less force is employed pushing the aft portion of the boat in a downward direction and more force is employed propelling the boat 13 forward.
Referring to FIG. 3, the internal details and configuration of the marine propulsion unit 31 of the present invention will be explained in great detail. The systems of marine propulsion unit 31 cooperate in a synergistic manner to produce an outboard engine having a low profile, low center of gravity, an aftwardly oriented center of gravity, an extended exhaust system having increased efficiency and silencing, and a reduced space requirement. In FIGS. 3-6, the marine propulsion unit 31 of the present invention is illustrated in operating position, attached to the transom 23 of a boat. The systems of marine propulsion unit 31 which cooperate to provide a superior outboard motor, include the structural support and steering system, the mechanical power transmission system, the cooling system, the exhaust system, and the tilt system. Each of these systems will be explored in order to familiarize the reader with the manner in which they ar cooperatively engaged by the marine propulsion unit 31 of the present invention.
With regard to structural support, marine propulsion unit 31 is adapted to be attached to transom 23 of a boat 13, of FIGS. 3, 4, 5 and 6. Forward of transom 13 is a motor well 33 which not only provides some support to transom 23, but is the space within which the marine propulsion unit 31 of the present invention must limit its movement. Motor well 33 usually includes side boundaries, as are well known, but they are not illustrated in the figures. Secured to transom 23 is a clamp bracket 35, which is usually attached to transom 23 by clamps (not shown in the figures). Attached to clamp bracket 35 is a series of resilient engine mounts 37. Resilient engine mounts 37 provide support to an engine 39. Clamp bracket 35 also supports an engine cowling 41, an engine hood 43, and a moveable cover 45.
As to the steering support system, clamp bracket 35 also lends structural support to a steering shaft 47 which it supports in a swivel bracket 49. The ends of steering shaft 47 are fixed to an upper steering bracket 51 and a lower steering bracket 53. This arrangement allows driveshaft housing 17 and lower unit 19 to pivot for steering movement about the swivel bracket 49 and the clamp bracket 35. The tilt support system includes an outer tilt bracket 55, which is connected to clamp bracket 35. An inner tilt bracket 57 is tiltable about outer tilt bracket 55. Both the outer and inner tilt brackets 55 and 57 are supportably pivotable about a pair of pivot pins 59. The inner tilt bracket 57 is further connected to drive shaft housing 17.
In the power transmission system, the horizontally oriented engine 39 is depicted as a two-cycle three cylinder in this engine although other configurations are possible and occupies a space previously referred to as the power head 15, and as has been previously discussed, is supported by resilient supports 37. Engine 39 has a flywheel 61 held in place by a nut 63 on a crankshaft 65. A silencer 67 is connected to a set of three horizontally disposed side draft carburetors 69 which are in turn connected to and discharge into an intake manifold 71. Intake manifold 71 is in communication with a crankcase 73, as is typically in the case of a two cycle engine. The crankshaft 65 is slitably journaled within crankcase 73 and is driven by connecting rods 75, which are in turn connected to pistons 77. Pistons 77 cooperate into one or more scavenging ports 79 for each cylinder, which enables engine 39 to receive a combustible mixture from the crankcase 73 into a combustion chamber 81, as is well known for two cycle engines. Spark plugs 83 provide ignition of the combustible mixture in a well known manner.
During combustion, mechanical power is transmitted from the crankshaft 65 to horizontally oriented output shaft 85. Note that the entire engine assembly, including piston 77, crankshaft 65, and output shaft 85 are horizontally oriented. This horizontal orientation enables engine 39 to be brought almost entirely forward of transom 23 and enables the low profile of marine propulsion unit 31 as is readily seen from FIGS. 3, 4 and 6. Output shaft 85 is connected to a generally horizontally oriented universal joint 87. Universal joint 87 is surrounded by a power transmission bellows 89 to provide flexible covering. An area 91 of universal joint 87, as well as the steering shaft 47, lies on the steering axis of the lower unit 19 and driveshaft housing 17. An area 93 of universal joint 87, as well as the pivot pins 59, lies on the tilt/trim axis of the outer tilt bracket 55 of clamp bracket 35, about which lower unit 19, driveshaft housing 17 and swivel bracket 49 tilt. Universal joint 87 is connected to an input driveshaft 95. At the end of input driveshaft 95 is a bevel gear 97, rotatable about a horizontal axis which engages a bevel gear 99 rotatable about a vertical axis. Bevel gear 99 is connected to one end of driveshaft 101 which extends through and is suitably journaled in driveshaft housing 17. Driveshaft 101 extends into the lower unit 19 where it is connected to a gear 103. Gear 103 engages counter-rotating gears 105 and 107 within a gear box 109. A clutch 111 is splined to a propeller shaft 113 and couples that shaft to either the gear 105 or 107 for selected forward or reverse drive. Propeller 21 is suitably fixed to propeller shaft 113 and is of a suitable type to make driving engagement with the water, such type dependent upon the load and running conditions of boat 13. Note the relative aft displacement of the driveshaft 101 and the driveshaft housing 17, which causes a more aftwardly center of gravity.
The extended exhaust system of the marine propulsion unit 31 of the present invention is best illustrated with reference to FIG. 3. In communication with each combustion chamber 81 of engine 39 is an upwardly extending exhaust port 115 that is forward of the transom 23. The exhaust ports 115 join into an exhaust manifold -17. The exhaust manifold 117 opens into an exhaust bellows 119. Exhaust bellows 119 is in communication with an exhaust muffler 121, having a horizontally extending inlet and a vertically extending body and outlet, said outlet labeled as number 123. The central part of muffler 121 forms an expansion chamber. Thus we see that noise is abated both through the right angle turn between the inlet connection with exhaust bellows 119 and with respect to the expanded body portion forming the expansion chamber. Outlet 123 opens into an exhaust chamber 125 which is in communication through a path not shown with the center portion of propeller 21. In this manner the exhaust gases are expelled through propeller 21, typically beneath the water line in order to improve silencing. The extended distance between exhaust ports 115 and the point where the exhaust gases are expelled through propeller 21 is made possible by bringing the engine 39 forward of the transom 23 while extending the driveshaft housing 17 and lower unit 19 farther aft of the transom 23.
To provide insulatory cooling water for the engine 39 and the exhaust system of the marine propulsion unit 31 of the present invention, a water jacketing system is provided. A water inlet, 127 provides water to a water pump 129. Water pump 129 pumps water through a conduit 131 and through a connected water hose 133. Water hose -33 is in communication with engine 39 through a path not shown, where it supplies water to cool the portions of engine 39 subject to heating. The cooling water exits engine 39 through a water jacket passage 135 which surrounds exhaust manifold 117. Water jacket passage 135 is connected to a water bellows 137. Water bellows 137 is connected to a water passage 139 surrounding muffler 121. Water passage 139 is in communication with a water chamber 141. Water chamber 141 comprises a transition passage 143 surrounding the passage 139 and in communication with an exit chamber 145. Exit chamber 145 contains a plurality of exit openings 147 through which the spent cooling water is expelled, thus completing its path through the cooling system.
The tilt and trim system is adjacent transom 23. A power tilt device is generally designated as 149. Power tilt device 149 has an electric motor 151 driving an oil pump (not shown) included in the power tilt device 149. Electric motor 151 is situated atop power tilt device 149. Adjacent electric motor 151 and connected to clamp bracket 35, at a point near the housing of power tilt device -49 is a tilt cylinder 153, having a tilt cylinder rod 155 pivotally attached to the upper inside portion of the driveshaft housing 17. Laterally adjacent the lower portion of tilt cylinder 153 is a trim cylinder 157 attached to power tilt device 149. Trim cylinder 157 has a trim cylinder rod 159 which makes contact with an arm -61 which is also attached to a portion of swivel bracket 49.
Note that tilt cylinder -53 is angled differently than trim cylinder 157. The tilt cylinder 153 is positioned to swing driveshaft housing 17 and lower unit 19 to a wide angle to an out of the water storage position. Trim cylinder 157 provides narrow angled trimming adjustment. Trimming adjustment is a fine adjustment made usually during cruise to achieve optimal fine angle adjustment of the lower unit 19 to adjust the quality of ride or select optimum angle of thrust of lower unit 19 for the most efficient operation. The most efficient operation will dictate a fine, or trimming adjustment based upon the loading and distribution of the loading within a boat.
Adjacent transom 23 near the base of power tilt device 149 is provided a structural member 163 of clamp bracket 35 having a stopping pin 165. An arm 167 attached to the swivel bracket 49 rests against stopping pin 165 and provides a limit from which both trim cylinder 157 and tilt cylinder 153 begin to provide a range of movement of the swivel bracket 49 and the driveshaft housing 17 and lower unit 19 and engine 43, with respect to clamp bracket 35 and engine 43. Tilt cylinder 153 also provides a shock absorbing function. When the boat is in forward motion, the tilt cylinder 153 acts as a shock absorber with respect to objects encountered by lower unit 19. In reverse, tilt cylinder 153 provides resistance to the rearward thrust of the lower unit 19.
The manner of trimming and tilting of marine propulsion unit 31 has certain advantages best illustrated with respect to FIG. 6. FIG. 6 illustrates the marine propulsion unit 31 in the tilted up out of the water position. In this position it can be seen that relative to transom 23, motor well 33, clamp bracket 35, engine 39, and engine cowling 41, that driveshaft housing 17 and lower unit 19 have changed position. No volume is displaced by engine cowling 41 and hood 43 as driveshaft housing 17 and lower unit 19 tilt upward. A portion of the tilt cylinder rod 155 is visible in extended position just above the top of clamp bracket 35. Arm 167 is swung away from engagement with stopper pin 165 (not visible in FIG. 6) which is previously shown in FIG. 3. The steerable pivoting from side to side in the plane normal to length of steering shaft 47 is still permissible during full tilt.
Referring to FIG. 3, it can be seen that the driveshaft 101 and driveshaft housing 17 generally, are displaced far aft of transom 23. The rearward displacement of driveshaft 101 and driveshaft housing 17 is enabled by the forward and horizontal orientation of engine 39 and its horizontally oriented output shaft 85. In conventional outboard motors, the engine has a vertical output shaft and must be located directly over its driveshaft.
The configuration of the marine propulsion unit 31 of the present invention also facilitates the utilization of an extended exhaust and cooling water passage which improves silencing. In a conventional marine propulsion unit, the exhaust passage has limitations based upon the shortened length of the unit. However, the marine propulsion unit 31 of the present invention has a much longer exhaust passage to facilitate the tunable adjustment of its dimension to match the frequency and throughput of the exhaust gases from engine 39. It is known that exhaust gas output creates back pressure on an engine both due to the total flowing pressure drop and to the resonance set up due to the noisiness of the exhaust. This is particularly true in two cycle engines such as the ones used in outboard motors, and of the engine utilized for marine propulsion unit 31 as presented here. A longer available exhaust path presents the opportunity to adjust the volume configuration in order to "tune" the exhaust path to improve the operating characteristic of the engine. The tuning of the exhaust path facilitates a lessened back pressure on the engine to provide greater efficiency and increased silencing.
In addition, the marine propulsion unit 31 of the present invention enables the design of a boat having a smaller motor well 33, because even in steering and tilting, the engine always keeps a generally stationary position which will derive the benefit of saving space, or the utilization of the space for other purposes. The utilization of marine propulsion unit 31 of the present invention may spawn a class of boats having smaller motor wells with more space provided for other uses.
The foregoing disclosure and description of the invention is illustrative and explanatory of a preferred embodiment of the invention, and various changes of the illustrated construction may be made without departing from the spirit and scope of the invention. | A marine propulsion unit, for mounting on the transom of a boat, has a horizontally oriented input shaft and has a lower drive unit which is angularly tiltable in the vertical plane without movement of the engine. The configuration enables the location of the driveshaft housing and lower unit at a point further aft of the transom to keep the marine propulsion unit's center of gravity in a more aftward position, enabling an extended length exhaust system, better control and handling of the exhaust, increased torque, and an increasing overall engine efficiency. The low profile of the marine propulsion unit coupled with its far forward pivot point requires a smaller motor well space and increased visibility in the direction aft of the boat. | 1 |
RELATED APPLICATIONS
The present invention was first described in and claims the benefit of U.S. Provisional Application No. 61/303,454 filed Feb. 11, 2010, the entire disclosures of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates generally to infant caretaking devices including infant pacifiers and bottles, and in particular, to a wireless locating system for infant caretaking devices including infant pacifiers and bottles.
BACKGROUND OF THE INVENTION
Misplacing small household items is one (1) of the most frustrating experiences of a daily routine. Such items become easily lost due to their small size, often falling in between seat cushions or under furniture, with no means to easily locate them. Other times, they may be accidentally carried from the room and left elsewhere in the home.
Some of the most frustrating objects to lose are child care items such as an infant bottle, sippy cup or pacifier. In addition to being an aggravation to locate the item, the situation is often exacerbated by the infant. In many cases, a caretaker does not being looking for a pacifier or bottle until the infant begins crying to indicate their need or desire of that item. As such, quick location and implementation is extremely desirable. In many cases, the infants themselves may throw, move, or otherwise misplace the item, making it nearly impossible for the caretaker to keep constant tabs on the location of all such items.
Various attempts have been made to provide item locating systems. Examples of these attempts can be seen by reference to several U.S. patents, including U.S. Pat. No. 4,101,873; U.S. Pat. No. 4,476,469; U.S. Pat. No. 5,686,891; U.S. Pat. No. 5,939,981; and U.S. Pat. No. 6,066,161. However, none of these designs are similar to the present invention.
While these systems fulfill their respective, particular objectives, each of these references suffer from one (1) or more of the aforementioned disadvantages. Many such systems are only adapted for particular types of items. Also, many such systems do not work with a plurality of items simultaneously. Furthermore, many such systems do not compensate for the loss of a transmitting item locator portion. In addition, many such systems would render an infant item such as a bottle unable to be washed without damaging the system. Accordingly, there exists a need for a locating system for infant items without the disadvantages as described above. The development of the present invention substantially departs from the conventional solutions and in doing so fulfills this need.
SUMMARY OF THE INVENTION
In view of the foregoing references, the inventor recognized the aforementioned inherent problems and observed that there is a need for a system by which a plurality of infant items including bottles and pacifiers can be quickly located without inhibiting the normal operation of those items. Thus, the object of the present invention is to solve the aforementioned disadvantages and provide for this need.
To achieve the above objectives, it is an object of the present invention to provide a locating system primarily intended for child accessories such as infant bottles, infant cups, and pacifiers.
Another object of the present invention is to include a plurality of retaining caps which can removably engage any one (1) of a plurality of such child accessories. Each retaining cap includes a speaker, a receiver, and a removable battery which receive a wireless signal from a transceiver and provide an audible alert with the speaker.
Yet still another object of the present invention is to include at least one (1) bottle body which threadingly engages a retaining cap at a lower end and includes conventional bottle features such as a removable lid and a nipple. The removable nature of the retaining cap allows the electrical portions of the system to be removed prior to washing the bottle.
Yet still another object of the present invention is to include at least one (1) hollow cup which receives a retaining cap in a manner similar to the bottle. The cup includes conventional child cup features including a removable lid with a sipping portion. The removable nature of the receiver similarly allows the electrical portions of the system to be removed prior to washing the cup.
Yet still another object of the present invention is to include at least one (1) pacifier including a threaded member at a rear portion for threadingly receiving a retaining cap. The retaining cap for the pacifier may be of a smaller size than the retaining caps utilized for the bottle or cup so as to keep the pacifier compact and lightweight, but the pacifier retaining cap includes similar electrical components and functions.
Yet still another object of the present invention is to comprise the transceiver of a key-fob style housing, allowing a caretaker to activate the audible alerts on any number of retaining caps in a portable manner. The key-fob style transceiver provides a compact control attachable to a key ring and includes a push-button control which transmits a wireless signal to the receivers.
Yet still another object of the present invention is to prevent loss of the transceiver and subsequent failure of the system by providing an audible alert and speaker within the transceiver. The user can actuate a control button on the recharging station to transmit a wireless signal to the transceiver and thereby enable a user to locate the transceiver in a manner similar to the retaining caps.
Yet still another object of the present invention is to provide a plurality of retaining caps, each including a rechargeable battery, such that the system can function in a continuous and modular manner. The recharging base includes a plurality of battery slots corresponding to the various sizes of batteries provided to the different retaining caps. A user can detach a battery from the corresponding retaining cap and place it against a pair of battery charging contacts within the appropriate battery slot to receive a charging current. The charging base is preferably connected to a household AC power supply.
Yet still another object of the present invention is to allow a user to selectively power off, power on, and monitor the status of the recharging base using a power button and a plurality of indicator lights which alert the user as to the charging and operating status of the system.
Yet still another object of the present invention is to provide a method of utilizing the device that provides a unique means of acquiring a desired number of infant bottles, infant cups, and pacifiers along with the charging station and transceiver; plugging the charging station into a wall outlet; activating the charging station by pressing the power button; inserting a desired number of batteries into the battery slots based upon anticipated child accessories to be utilized; allowing a sufficient period of time for the batteries to charge; loading each battery into a respective retaining cap; threadingly attaching the retaining caps to each child accessory; allowing a child or children to utilize the child accessories in a normal manner; transmitting a signal to activate all utilized speakers which causes them to broadcast an audible alarm; locating and retrieving the child accessories; removing the batteries from the retaining caps; returning the batteries into the battery slots of the charging station until needed again; and utilizing the transmitter button portion of the charging station to locate the transceiver in an event of a misplaced transceiver.
Further objects and advantages of the present invention will become apparent from a consideration of the drawings and ensuing description.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages and features of the present invention will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which:
FIG. 1 is an exploded perspective view of an infant bottle 20 which is utilized as part of a locating system for child accessories 10 , according to a preferred embodiment of the present invention;
FIG. 2 a is a bottom perspective view of the infant bottle 20 depicting an open bottle retaining cap 26 , according to a preferred embodiment of the present invention;
FIG. 2 b is a bottom perspective view of the bottle retaining cap 26 , according to a preferred embodiment of the present invention;
FIG. 2 c is a section view of the bottle retaining cap 26 taken along line A-A (see FIG. 2 a ), according to a preferred embodiment of the present invention;
FIG. 3 is an exploded perspective view of an infant cup 30 which is utilized as part of the locating system for child accessories 10 , according to a preferred embodiment of the present invention;
FIG. 4 a is a bottom perspective view of the infant cup 30 depicting an open cup retaining cap 35 , according to a preferred embodiment of the present invention;
FIG. 4 b is a bottom perspective view of the cup retaining cap 35 , according to a preferred embodiment of the present invention;
FIG. 4 c is a section view of the cup retaining cap 35 taken along line B-B (see FIG. 4 a ), according to a preferred embodiment of the present invention;
FIG. 5 is an exploded perspective view of a pacifier 40 which is utilized as part of the locating system for child accessories 10 , according to a preferred embodiment of the present invention;
FIG. 6 a is a bottom perspective view of the pacifier 40 depicting an open pacifier retaining cap 45 , according to a preferred embodiment of the present invention;
FIG. 6 b is a bottom perspective view of the pacifier retaining cap 45 , according to a preferred embodiment of the present invention;
FIG. 6 c is a section view of the pacifier retaining cap 45 taken along line C-C (see FIG. 6 a ), according to a preferred embodiment of the present invention;
FIG. 7 is a top perspective view of a transceiver 60 which is also utilized as part of the locating system for child accessories 10 , according to a preferred embodiment of the present invention;
FIG. 8 is a bottom perspective view of the transceiver 60 , according to a preferred embodiment of the present invention;
FIG. 9 is a perspective view of a recharging station 50 which is further utilized as part of the locating system for child accessories 10 , according to a preferred embodiment of the present invention;
FIG. 10 is a section view of the recharging station 50 taken along line D-D (see FIG. 9 ), according to a preferred embodiment of the present invention; and,
FIG. 11 is an electrical block diagram of the view of the locating system for child accessories 10 , according to a preferred embodiment of the present invention.
DESCRIPTIVE KEY
10
locating system for child accessories
20
infant bottle
21
bottle body
22
bottle nipple
23
bottle nipple retaining ring
24
bottle cap
25
bottle threaded member
26
bottle retaining cap
27
bottle retaining cap thread
28
bottle retaining cap aperture
29a
bottle receiver/speaker
29b
bottle battery clip
30
infant cup
31
cup body
33
cup lid/spout
34
cup threaded member
35
cup retaining cap
36
cup retaining cap thread
37
cup retaining cap aperture
38
cup receiver/speaker
39
cup battery clip
40
pacifier
41
pacifier cap
42
pacifier body
43
pacifier threaded member
44
pacifier nipple
45
pacifier retaining cap
46
pacifier handle
47
pacifier aperture
48
pacifier retaining cap thread
49a
pacifier receiver/speaker
49b
pacifier battery clip
50
recharging station
51
recharging housing
52
first battery slot
53
cord
54
second battery slot
55a
first battery contact body
55b
second battery contact body
56
indicator light
57
transmitter button
58
power button
59
charger transmitter
60
transceiver
62
transceiver body
64
transceiver activation button
65
transceiver aperture
66
key ring
67
transceiver battery compartment
68
transceiver battery
69
transceiver/speaker
70
first battery
75
second battery
81
audible alarm
100
first signal
110
second signal
120
electrical wiring
200
key
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The best mode for carrying out the invention is presented in terms of its preferred embodiment, herein depicted within FIGS. 1 through 11 . However, the invention is not limited to the described embodiment and a person skilled in the art will appreciate that many other embodiments of the invention are possible without deviating from the basic concept of the invention, and that any such work around will also fall under scope of this invention. It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope.
The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items.
The present invention describes a locating system for child accessories (herein described as the “system”) 10 , which provides a locating system primarily intended to locate a child's accessory such as an infant bottle 20 , an infant cup 30 , or a pacifier 40 . The system 10 also provides a key fob transceiver 60 , which is carried by a parent or care provider on a key ring 66 . In such a manner, the parent or care provider can simply activate the transceiver 60 to locate the lost child accessory 20 , 30 , 40 . The child accessory 20 , 30 , 40 will in turn alert the care giver of its location via an emitted alarming sound. The system 10 also comprises a central recharging station 50 . The system 10 is purchased having a desired number and combination of infant bottles 20 , infant cups 30 , and pacifiers 40 , each to be of a conventional design; however, said bottles 20 , infant cups 30 , and pacifiers 40 are depicted here comprising enhanced locating features.
Referring now to FIG. 1 , an exploded perspective view of the infant bottle 20 which is utilized as part of the system 10 , FIG. 2 a , a bottom perspective view of the infant bottle 20 depicting an open bottle retaining cap 26 , FIG. 2 b , a bottom perspective view of the bottle retaining cap 26 , and FIG. 2 c , a section view of the bottle retaining cap 26 taken along line A-A (see FIG. 2 a ), according to the preferred embodiment of the present invention, are disclosed. The infant bottle 20 comprises a common molded plastic liquid dispensing vessel having expected elements such as a cylindrical bottle body 21 , a bottle nipple 22 , a bottle nipple retaining ring 23 , and a bottle cap 24 . The bottle body 21 provides a containment means for fluid to be consumed by an infant. The bottle nipple 22 is a rubberized drinking teat which is removably attached to an upper portion of the bottle body 21 with a bottle nipple retaining ring 23 which threadably engages said upper portion of the bottle body 21 . The bottle cap 24 comprises a generally cylindrical shape which provides a sealing and protecting feature to the infant bottle 20 while in use. The bottle cap 24 preferably engages an upper portion of the bottle nipple retaining ring 23 via a friction fitting means. The infant bottle 20 may comprise various sizes, shapes, and other functional or aesthetic features without limiting the scope of the system 10 .
A bottom underside surface of the bottle body 21 comprises a hollow bottle threaded member 25 which enables a bottle retaining cap 26 to be removed or affixed to said bottle body 21 . The bottle threaded member 25 downwardly extends from and is integrally molded to the bottle body 21 further including a plurality of threads on an exterior circumference. The bottle threaded member 25 is positioned over the electronics within the bottle retaining cap 26 . The bottle retaining cap 26 comprises a plurality of bottle retaining cap threads 27 on an inner circumference which engage the threads on the bottle threaded member 25 . The threaded engaging of the bottle body 21 to the bottle retaining cap 26 is preferably a child-proof threaded design to discourage tampering. The bottle retaining cap 26 comprises the electronics used for searching for the misplaced infant bottle 20 . Positioned within the bottle retaining cap 26 are a bottle receiver/speaker 29 a and a first battery 70 . The bottle receiver/speaker 29 a comprises a miniature radio frequency (RF) receiver and a commercially available piezo-type miniature speaker unit. The bottle receiver/speaker 29 a receives a first signal 100 (see FIG. 11 ) from a transceiver 60 and broadcasts an audible alarm 81 . The audible alarm 81 is heard through a plurality of bottle retaining cap apertures 28 which are depicted on a rear surface of the bottle retaining cap 26 to alert a user of the location of the infant bottle 20 . The first battery 70 is secured into an electrically connected position with common bottle battery clips 29 b . With the first battery 70 within the bottle battery clips 29 b current is directed to the bottle receiver/speaker 29 a and awaits the first signal 100 to broadcast the audible alarm 81 .
Referring now to FIG. 3 , an exploded perspective view of the infant cup 30 which is utilized as part of the system 10 , FIG. 4 a , a bottom perspective view of the infant cup 30 depicting an open bottle retaining cap 35 , FIG. 4 b , bottom perspective view of the cup retaining cap 35 , and FIG. 4 c , a section view of the cup retaining cap 35 taken along line B-B (see FIG. 4 a ), according to the preferred embodiment of the present invention, are disclosed. The infant cup 30 comprises expected features such as a cylindrical cup body 31 and a cup lid/spout 33 as commonly found in similar devices. The cup body 31 provides a containment means for fluid to be consumed by an infant. The cup lid/spout 33 provides a drinking means and securing means to the internal fluid. The cup lid/spout 33 threadably engages said upper exterior portion of the cup body 31 . The infant cup 30 may comprise various sizes, shapes, and other functional or aesthetic features without limiting the scope of the system 10 .
A bottom underside surface of the cup body 31 comprises a hollow cup threaded member 34 which enables a cup retaining cap 35 to be removed or affixed as similar to the abovementioned infant bottle 20 . The cup threaded member 34 downwardly extends from and is integrally molded to the cup body 31 further including a plurality of threads on an exterior circumference. The cup retaining cap 35 comprises a plurality of cup retaining cap threads 36 on an inner circumference which engage the threads on the cup threaded member 34 . The threaded engaging of the cup body 31 to the cup retaining cap 35 is preferably a child-proof threaded design to discourage tampering. The cup retaining cap 35 comprises the electronics used for searching for the misplaced infant cup 30 . Positioned within the cup retaining cap 35 are a cup receiver/speaker 38 and a first battery 70 . The cup receiver/speaker 38 comprises a miniature radio frequency (RF) receiver and a commercially available piezo-type miniature speaker unit. The cup receiver/speaker 38 receives a first signal 100 (see FIG. 11 ) from a transceiver 60 and broadcasts an audible alarm 81 . The audible alarm 81 is heard through a plurality of cup retaining cap apertures 37 which are depicted on a rear surface of the cup retaining cap 35 to alert a user of the location of the infant cup 30 . The first battery 70 is secured into an electrically connected position with the cup battery clips 39 . With the first battery 70 within the cup battery clips 39 current is directed to the cup receiver/speaker 38 and awaits the first signal 100 to broadcast the audible alarm 81 .
Referring now to FIG. 5 , an exploded perspective view of a pacifier 40 which is utilized as part of the system 10 , FIG. 6 a , a bottom perspective view of the pacifier 40 depicting an open pacifier retaining cap 45 , FIG. 6 b , a bottom perspective view of the pacifier retaining cap 45 , and FIG. 6 c , a section view of the pacifier retaining cap 45 taken along line C-C (see FIG. 6 a ), according to the preferred embodiment of the present invention, are disclosed. The pacifier 40 comprises expected features such as a pacifier cap 41 , a pacifier body 42 , a pacifier nipple 44 , and a pacifier handle 46 . The pacifier body 42 comprises a cylindrical shape and the pacifier nipple 44 is removable to enable it to be interchangeable within other nipple styles. The pacifier cap 41 protects the pacifier nipple 44 when the pacifier 40 is not being utilized. The pacifier 40 may comprise various sizes, shapes, and other functional or aesthetic features without limiting the scope of the system 10 .
A bottom underside surface of the pacifier body 42 comprises a hollow pacifier threaded member 43 which enables a pacifier retaining cap 45 to be removed or affixed as similar to the abovementioned infant bottle 20 . The pacifier threaded member 43 downwardly extends from and is integrally molded to the pacifier body 42 further including a plurality of threads on an exterior circumference. The pacifier retaining cap 45 comprises a plurality of pacifier retaining cap threads 48 on an inner circumference which engage the threads on the pacifier threaded member 43 . The threaded engaging of the pacifier body 42 to the pacifier retaining cap 45 is preferably a child-proof screw-on design to discourage tampering. The pacifier retaining cap 45 comprises the electronics used for searching for the misplaced pacifier 40 . Positioned within the pacifier retaining cap 45 are a pacifier receiver/speaker 49 a and a second battery 75 . The pacifier receiver/speaker 49 a comprises a miniature radio frequency (RF) receiver and a commercially available piezo-type miniature speaker unit. The pacifier receiver/speaker 49 a receives a first signal 100 (see FIG. 11 ) from a transceiver 60 and broadcasts an audible alarm 81 . The audible alarm 81 is heard through a plurality of pacifier apertures 47 which are depicted on a rear surface of the pacifier retaining cap 45 to alert a user of the location of the pacifier 40 . The second battery 75 is secured into an electrically connected position with the pacifier battery clips 49 b . With the second battery 75 within the pacifier battery clips 49 b current is directed to the pacifier receiver/speaker 49 a and awaits the first signal 100 to broadcast the audible alarm 81 . A bottom surface of the pacifier retaining cap 45 comprises an integrally molded pacifier handle 46 which enables a care provider or infant to grasp said pacifier handle 46 . The pacifier handle 46 is depicted as comprising an ergonomic “C”-shape, yet other shapes may be utilized without limiting the scope of the system 10 .
Referring now to FIG. 7 , a top perspective view of a transceiver 60 which is utilized as part of the system 10 and FIG. 8 , a bottom perspective view of the transceiver 60 , according to the preferred embodiment of the present invention, are disclosed. The transceiver 60 preferably comprises a key-fob type unit comprising a compact decorative transceiver body 62 which is herein depicted as a flower design, yet other designs or figures may be utilized without limiting the scope of the system 10 . An upper surface of the transceiver body 62 comprises a transceiver activation button 64 at a central position. The transceiver body 62 is displayed from a desired location by an affixed key ring 66 which is inserted through a transceiver aperture 65 and is capable of facilitating a plurality of common keys 200 or similar items. The transceiver 60 is to be powered using an internal transceiver battery 68 (see FIG. 11 ). The transceiver battery 68 is accessed by the transceiver battery compartment 67 on a bottom surface of the transceiver body 62 . The transceiver 60 preferably provides a compact size which further provides convenient storage in a user's pocket or purse.
The transceiver 60 provides a two-way communication means with the child accessories 20 , 30 , 40 via transmission of a first signal 100 , and with the recharging station 50 via receipt of a second signal 110 . Upon pressing the transceiver activation button 64 , the first signal 100 is transmitted to one (1) or more child accessories 20 , 30 , 40 , by initiating an audible alarm 81 from a receiver/speaker 29 a , 38 , 49 a for a preset duration to locate the child accessories 20 , 30 , 40 . Wireless communication between the charging station 50 and the transceiver 60 is accomplished in like manner by pressing a transmitter button 57 located upon a front surface of the charging station 50 (see FIG. 9 ) which in turn transmits a second signal 110 to the transceiver 60 to activate an audible alarm 81 from a transceiver/speaker 69 (also see FIG. 11 ) for a preset duration which enables a user to locate the transceiver 60 when lost.
Referring now to FIG. 9 , a perspective view of a recharging station 50 which is utilized as part of the system 10 and FIG. 10 , a section view of the recharging station 50 taken along line D-D (see FIG. 9 ), according to the preferred embodiment of the present invention, are disclosed. The system 10 comprises a recharging station 50 to provide a charging means to the batteries 70 , 75 when the desired accessory 20 , 30 , 40 is not used and a locating means to the transceiver body 62 . The batteries 70 , 75 are preferably common rechargeable lithium-ion button cell DC batteries which utilize current battery technologies. The first battery 70 is slightly larger that the second battery 75 which is provided in this fashion to fit a corresponding child accessory 20 , 30 , 40 . The batteries 70 , 75 are removed from the respective receiver clips 29 b , 39 , 49 b and charged as needed using the charging station 50 . The recharging station 50 comprises a generally rectangular recharging housing 51 which receives power from a common household AC outlet using a power cord 53 . The recharging station 50 is capable of providing a charging current coincidentally to a plurality of batteries 70 , 75 . The batteries 70 , 75 comprise differing cylindrical dimensions and are insertingly engaged into a plurality of respective first battery slots 52 and second battery slots 54 along a front surface of said recharging station 50 . The slots 52 , 54 provide rectangular apertures being sized so as to slidingly receive the respective batteries 70 , 75 within. Within each first battery slot 52 is a common first battery contact body 55 a which accepts the first battery 70 for charging. Similarly, within each second battery slot 54 is a second battery contact body 55 b which accepts the second battery 75 for charging. The battery contacts 55 a , 55 b include a pair of side walls, a rear wall, and a bottom panel which is in electrical communication with a shelf located beneath said bottom panel to interconnect each battery contact 55 a , 55 b to the power source. The battery contact body 55 a , 55 b is interconnected with electrical wiring 120 to charge said battery 70 , 75 by forcing current through said battery 70 , 75 in a conventional manner. Different sized batteries 70 , 75 would correspond to varying internal space of the differently sized child accessories 20 , 30 , 40 .
The charging station 50 further comprises a plurality of battery charging indicator lights 56 , a transmitter button 57 , and a power button 58 . The power button 58 provides normal activation of the charging station 50 and is preferably a slide switch having an illuminated button so as to indicate the charging station 50 is operational. The charging indicator lights 56 are preferably light-emitting diodes (LED's) which provide communication of a charging status for one (1) or more batteries 70 , 75 inserted within respective battery slots 52 , 54 . The number of indicator lights 56 equals the number of slots 52 , 54 therein each indicator light 56 is positioned adjacent to an individual slot 52 , 54 . The indicator lights 56 preferably blink as to define an in-process charging status and are at a steady state when charging is complete, yet other configurations may be utilized without limiting the scope of the system 10 . The transmitter button 57 is preferably a common pushbutton which is depressed to transmit a second signal 110 to locate the transceiver 60 . The transmitter button 57 is interconnected to charger transmitter 59 (see FIG. 11 ) emits the second signal 110 to the transceiver 60 .
Referring now to FIG. 11 is an electrical block diagram of the system 10 , according to the preferred embodiment of the present invention, is disclosed. The transceiver 60 is powered with a rechargeable button cell transceiver battery 68 (which may be recharged with the recharging station 50 ) as the transceiver activation button 64 is depressed. The transceiver activation button 64 transmits a first signal 100 from the transceiver/speaker 69 to the child accessories 20 , 30 , 40 . Each child accessory 20 , 30 , 40 comprises respective receiver/speaker 29 a , 38 , 49 a which broadcasts an audible alarm 81 when the signal 100 locates said accessory 20 , 30 , 40 . Each accessory 20 , 30 , 40 is powered with a respective battery 70 , 75 and interconnected with electrical wiring 120 .
In the instance that the transceiver 60 is misplaced the recharging station 50 is utilized to locate said transceiver 60 . With current supplied to the recharging station 50 by the power cord 53 the transmitter button 57 is depressed to transmit a second signal 110 via the charger transmitter 59 to the transceiver/speaker 69 . When the transceiver 60 is located an audible alarm 81 is broadcasted from the transceiver/speaker 69 .
The charging station 50 preferably lowers the power rating distributed from the AC power cord 53 to levels which can handle the DC batteries 70 , 75 with common techniques such as a transformer. With the power button 58 activated current is sent to each battery contact body 55 a , 55 b . When a battery 70 , 75 is inserted into the battery contact body 55 a , 55 b a respective indicator light 56 illuminates and said battery 70 , 75 charges.
It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope.
The preferred embodiment of the present invention can be utilized by the common user in a simple and effortless manner with little or no training. After initial purchase or acquisition of the system 10 , it would be installed as indicated in FIG. 11 .
The method of utilizing the system 10 may be achieved by performing the following steps: acquiring the system 10 ; purchasing a desired number of infant bottles 20 , infant cups 30 , and pacifiers 40 along with the charging station 50 and transceiver 60 ; plugging the charging station 50 into a conventional wall outlet using the cord 53 ; activating the charging station 50 by pressing the power button 58 ; inserting a desired number of first batteries 70 into the first battery slots 52 ; inserting a desired number of second batteries 75 into the second battery slots 54 based upon anticipated child accessories 20 , 30 , 40 to be utilized; allowing a sufficient period of time for said batteries 70 , 75 to obtain a charge as indicated by the respective indicator lights 56 ; loading each battery 75 , 70 into respective clip 29 b , 39 , 49 b ; threadingly attaching the retaining caps 26 , 35 , 45 upon each child accessory 20 , 30 , 40 ; filling the infant bottles 20 and infant cups 30 with a desired fluid; allowing a child or children to utilize the child accessories 20 , 30 , 40 for drinking or comforting in a normal manner; transmitting a first signal 100 to activate all utilized receiver/speakers 29 a , 38 , 49 a which causes them to broadcast an audible alarm 81 ; locating and retrieving the child accessories 20 , 30 , 40 to be used for continued use or cleaning; completing normal use of the child accessories 20 , 30 , 40 until ready for normal washing and/or sterilization; removing the batteries 70 , 75 from the retaining caps 26 , 35 , 45 ; returning the batteries 70 , 75 into the battery slot portions 52 , 54 of the charging station 50 until needed again; and utilizing the transmitter button 57 portion of the charging station 50 to locate the transceiver 60 in an event of a misplaced transceiver 60 ; and, benefiting from timely location and retrieval of the child accessories 20 , 30 , 40 using the present invention 10 .
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention and method of use to the precise forms disclosed. Obviously many modifications and variations are possible in light of the above teaching. The embodiment was chosen and described in order to best explain the principles of the invention and its practical application, and to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions or substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but is intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention. | An integral locating system for child's drinkware accessories comprises a receiver with a speaker removably attached to a rear portion of each accessory. The speaker is activated by a remotely located transceiver preferably carried by or located adjacent to the parent or care provider. In such a manner, the parent or care provider can depress an activation button on the transceiver to locate the specific article. The article will alert in response period of seconds to allow the parent or care provider to locate it. The receiver unit is removable from the child's drinkware accessory to allow the article to be washed or sterilized. The receiver unit is placed in a central recharging station that accepts the different sized receivers for recharging. | 6 |
FIELD OF INVENTION
[0001] The present invention relates to token activation, and particularly, but in no way limited to, activation of a financial card.
BACKGROUND OF INVENTION
[0002] Financial cards, such as ATM cards, credit cards, bank cards, and the like, are provided to allow customers of the card issuer to make purchases without using cash. Financial cards typically require a user to know an associated secret number (a personal identification number (PIN) typically comprising four digits) prior to being able to withdraw cash from an ATM. Since anyone possessing a financial card can access funds if they know the associated PIN, it is imperative that the card issuer only provides the PIN to the true cardholder. This is typically achieved by the card issuer sending a new financial card in a separate mailing to the PIN, and by requiring the cardholder to activate the financial card, for example, by answering some security questions, prior to use of the financial card.
[0003] Although this process generally works quite well, it is expensive, time consuming to administer, and has security problems.
SUMMARY OF INVENTION
[0004] Accordingly, the invention generally provides methods, systems, apparatus, and software for activating a token using a customer's current token.
[0005] In addition to the Summary of Invention provided above and the subject matter disclosed below in the Detailed Description, the following paragraphs of this section are intended to provide further basis for alternative claim language for possible use during prosecution of this application, if required. If this application is granted, some aspects of the invention may relate to claims added during prosecution of this application, other aspects may relate to claims deleted during prosecution, other aspects may relate to subject matter never claimed. Furthermore, the various aspects detailed hereinafter are independent of each other, except where stated otherwise. Any claim corresponding to one aspect should not be construed as incorporating any element or feature of the other aspects unless explicitly stated in that claim.
[0006] According to a first aspect there is provided a method of activating a token at a self-service terminal, the method comprising: receiving an active token from a customer; authenticating the customer using the active token and an associated identifier; receiving an inactive token from the customer; validating that the inactive token relates to the same customer as the active token; and, in the event of successful validation, activating the inactive token.
[0007] Activating the inactive token may be performed directly by the terminal (for example, by writing a PIN or PIN offset onto the token) or indirectly (for example, by sending a request to a remote host to activate the token).
[0008] The tokens may be cards, such as financial cards, loyalty cards, or the like.
[0009] The associated identifier may be a PIN, a biometric feature, answers to security questions, or the like.
[0010] Activating the inactive token may include allowing the customer to select a PIN for the inactive token or assigning a PIN to the inactive token.
[0011] The method may comprise the further step of retaining the inactive token in the event of an unsuccessful validation. Alternatively, the method may comprise the further step of returning the inactive token to the customer in the event of an unsuccessful validation.
[0012] The self-service terminal may be an automated teller machine (ATM). The self-service terminal may be part of a network of such terminals.
[0013] According to a second aspect there is provided a computer program for executing on a self-service terminal, the computer program being operable, when executed, to implement the steps of the first aspect.
[0014] By virtue of these, aspects, a customer having one financial card (such as an ATM card) can go to an ATM and use that financial card to activate a newly-received, but not yet activated, financial card. This reduces the need for the card issuer to provide call centers to confirm that the person trying to activate a newly-received card is the true cardholder.
[0015] These and other aspects will be apparent from the following specific description, given by way of example, with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a schematic view of a customer using a self-service terminal to implement a method according to one embodiment of the present invention;
[0017] FIG. 2 is a block diagram of a part (the controller) of the terminal of FIG. 1 ; and
[0018] FIG. 3 is a flowchart illustrating a card activation flow of an application executing on the controller of FIG. 2 .
DETAILED DESCRIPTION
[0019] Reference is first made to FIG. 1 , which is a side schematic view of a self-service terminal 10 (in the form of an ATM) being used by a customer 12 to implement a method according to one embodiment of the present invention.
[0020] The ATM 10 includes a user interface 14 for receiving input from, and outputting information to, the customer 12 .
[0021] The user interface 14 comprises: a molded fascia 16 defining slots (not shown in detail) for accessing devices located within the ATM 10 and in registration with the slots; a display 20 aligned with opposing columns of function defined keys (FDKs); an encrypting keypad 22 ; a token reader 24 , in the form of a motorized card reader/writer (MCRW) device; a printer 26 ; and a media dispenser 28 in the form of a cash dispenser.
[0022] The ATM 10 also includes an internal journal printer 30 for creating a record of all transactions executed by the ATM 10 , a network connection 32 (in the form of a network card) for communicating with a remote transaction host (not shown) for authorizing transactions, and an ATM controller 34 for controlling the operation of the various devices ( 18 to 32 ).
[0023] The ATM controller 34 is shown in more detail in FIG. 2 . The controller 34 comprises a BIOS 40 stored in non-volatile memory, a microprocessor 42 , associated main memory 44 , and storage space 46 in the form of a disk drive.
[0024] In use, the ATM 10 loads an operating system kernel 50 and an ATM application program 52 into the main memory 44 . The ATM application program 52 includes conventional routines and objects for controlling the operation of the ATM 10 , such as providing the sequence of screens used in each transaction (referred to as the application flow) and monitoring the condition of each device within the ATM 10 (state of health monitoring), as is known to those of skill in the art. In addition to these conventional functions, the ATM application program 52 includes a card activation routine.
[0025] Card Activation Transaction
[0026] A typical card activation transaction will now be described with reference to FIG. 3 , which is a flowchart illustrating a card activation flow 100 of the ATM application program 52 .
[0027] When the customer 12 arrives at the ATM 10 , the customer inserts his/her ATM card, which is read by the MCRW device 24 (step 102 ).
[0028] The ATM application program 52 then presents a screen inviting the customer 12 to enter his/her PIN. The customer 12 then types in his/her PIN, which is detected by the encrypting keypad 22 (step 104 ).
[0029] The ATM application program 52 then presents a list of transaction options on the display 20 , including conventional transactions (cash withdrawal, statement printing, and the like) and a card activation transaction.
[0030] The customer 12 then requests the card activation transaction, for example, using the FDKs. This selection is detected by the ATM controller 34 (step 106 ). In response to this request, the ATM application program 52 stores information read from the ATM card in a temporary local file 54 ( FIG. 2 ) (step 108 ) and then ejects the customer's ATM card (step 110 ).
[0031] Once the customer 12 has removed his/her ATM card, the ATM application program 52 then presents a card screen on the display 20 inviting the customer 12 to insert a financial card that is not yet activated (step 112 ).
[0032] The customer 12 inserts a new card that he/she has recently received (for example, by mail). The MCRW device 24 reads this new card (step 114 ), and compares the contents of this new card (for example, the customer's name) with the corresponding details read from the customer's ATM card and stored in temporary local file 54 (step 116 ).
[0033] If the details do not match, then the ATM application program 52 denies the request (step 118 ) and implements any actions predefined by the ATM owner or card issuer. For example, the ATM may notify the remote transaction host (not shown) that there has been a new card activation failure, and/or the MCRW may capture the new card.
[0034] If the details do match, then the ATM application program 52 requests the customer 12 to select a PIN for the new card (step 120 ), and in response to the entered PIN, the ATM application program 52 creates a PIN assignment message for transmission to the remote transaction host (not shown) (step 122 ).
[0035] The PIN assignment message includes the following encrypted information: the ATM card number used for the transaction, the entered PIN (or a PIN offset) associated with that ATM card, the new card number, and the selected PIN (or a PIN offset for the selected PIN) for the new card.
[0036] The ATM application program 52 then transmits the PIN assignment message to the remote transaction host (not shown) (step 124 ) and awaits confirmation of the PIN assignment and card activation.
[0037] The remote transaction host (not shown) receives and parses the PIN assignment message to ascertain if the ATM card number and PIN are correct for that customer. If the ATM card number and PIN combination is not correct, then the new card is not activated and the new PIN is not assigned. The remote transaction host (not shown) then transmits a transaction denial message to the ATM 10 .
[0038] If the ATM card number and PIN combination is correct, then the new card is activated and the new PIN is assigned to that new card by the remote transaction host (not shown). The remote transaction host (not shown) then transmits a transaction confirmation message to the ATM 10 .
[0039] The ATM 10 then presents the customer 12 with either a transaction denial message or a transaction confirmation message, depending on the response from the remote transaction host (not shown) (step 126 ).
[0040] If the transaction is confirmed, then the ATM 10 ejects the new card to the customer 12 (step 128 ), who can then use the new card for transactions.
[0041] It will now be appreciated that this embodiment has the advantage that where a financial institution issues multiple cards to the same customer, that customer can use an already activated card to activate a newly-received card, thereby avoiding the potential security problems associated with mailing a PIN to the customer, and also decreasing the amount of work done by a call centre that would otherwise have to ask security questions to activate the newly-issued card.
[0042] Various modifications may be made to the above described embodiment within the scope of the invention, for example, in other embodiments, the token may not be a card, it may be key fob, a ring, or the like.
[0043] In other embodiments, a biometric reading may be provided as the token or as the identifier associated with the token. In other embodiments, answers to security questions, or the like, may be used to authenticate the identity of the customer.
[0044] In other embodiments, a card other than a financial card may be used, for example, a loyalty card, a telephone card, or the like.
[0045] In other embodiments the self-service terminal may activate the new card directly, for example, by storing the newly-selected PIN (or an offset thereof) on the new card.
[0046] In other embodiments, the self-service terminal may actually issue a new card to the customer so that no card has to be mailed to the customer.
[0047] The steps of the methods described herein may be carried out in any suitable order, or simultaneously where appropriate. The methods described herein may be performed by software in machine readable form on a tangible storage medium or as a propagating signal.
[0048] The terms “comprising”, “including”, “incorporating”, and “having” are used herein to recite an open-ended list of one or more elements or steps, not a closed list. When such terms are used, those elements or steps recited in the list are not exclusive of other elements or steps that may be added to the list. | A method of activating a taken at a self-service terminal is described. The method comprises receiving an active token (such as a financial card) from a customer. The terminal then authenticates the customer using the active token and an associated identifier, which may be a PIN. The terminal then receives an inactive token from the customer (such as a newly-issued card), and validates that the inactive token relates to the same customer as the active token. In the event of successful validation, the terminal then activates the inactive token, either directly or indirectly. | 6 |
This is a division of 115,214 filed 10/30/87, now U.S. Pat. No. 4,784,693.
This invention is directed to a novel cementing composition, a novel aqueous hydraulic cement slurry, and a novel process of using the same, as well as a novel composition useful as a fluid loss additive in all the above. Specifically, this invention is directed to a cementing composition and an aqueous hydraulic cement slurry containing, as a fluid loss control additive, water-soluble, nonionic hydrophobically modified hydroxyethyl cellulose (HMHEC) alone or with water-soluble, nonionic hydroxyethyl cellulose (HEC). In addition, this invention is directed to a novel composition comprising HMHEC and HEC.
BACKGROUND OF THE INVENTION
Hydraulic cements, i.e., inorganic cements that harden or set under the influence of water, are frequently used in cementing operations associated with oil, gas, water and brine wells, as well as dam and tunnel construction. For instance, aqueous hydraulic cement slurries are used, during or after the completion of the drilling of an oil or gas well, to fill the annulus between the borehole wall and the outside of the casing. Usually, such wells are cemented by pumping a cement slurry downwardly though the casing with a shoe and/or float valve and then upwardly into the annulus surrounding the casing. The cement (a) provides a sheath surrounding the casing that prevents or inhibits communication between the various formations penetrated by the well, (b) aids in bonding and supporting the casing, (c) protects the casing from corrosion, (d) prevents blowouts by quickly forming a seal, (e) protects the casing from shock loads in drilling deeper, and (f) aids in sealing off zones of lost circulation.
Hydraulic cements manufactured for use in oil and gas wells are subject to wide ranges of temperature and pressure when in position in a well and differ considerably from cements used at atmospheric conditions. As a result, specifications covering eight classes of oil well cements, designated Classes A, B, C, D, E, F, G and H, are provided by the American Petroleum Institute (API). These cements comprise portland cement and a variety of cementing additives, such as those discussed below. Portland cement used in the cements classified by API are primarily comprised of about 40 to about 60% tricalcium silicate, about 15 to about 30% B-dicalcium silicate, about 8 to about 12% tetracalcium aluminoferrite and about 3 to about 8% tricalcium aluminate, with the total of tricalcium silicate and dicalcium silicate generally being about 75 to about 80% (Free CaO and MgO are generally held below about 1.5% and about 5%, respectively). Other hydraulic cements used in such wells are aluminous or pozzolanic cements. Cements and cementing are described by D. K. Smith in Cementing, American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. (1976).
In many uses of hydraulic cements, it is necessary for an aqueous cement slurry to be emplaced within or next to a porous medium, for example, earthen strata in the cementing of oil and drilling wells. When such is the case, water filters out of the slurry and into the strata during the setting period. When this occurs to an appreciable extent there usually results an uncontrolled setting rate, improper placement, impaired strength properties and contamination of the surrounding strata. The loss of fluids into the surrounding strata may be controlled by incorporation of fluid loss control additives or agents into the hydraulic cement. Fluid loss control additives for use in such cements include copolymers of N,N, dimethylacrylamide and 2-acrylamide, 2-methyl propane sulfonic acid as described by Rao et al in U.S. Pat. No. 4,515,635, modified alkylenediamine or polyalkylenepolyamine compositions as described by Willis et al in PCT International Publication No. WO 85/01935, and polysacharides such as HEC as described by Hook in U.S. Pat. No. 3,483,007.
Use of synthetic polymers as fluid loss agents is expensive. Therefore, there has been a desire to use less expensive natural polymers such as HEC. Although HEC provides good fluid loss, there is still a desire to reduce costs by replacing HEC with a more efficient and less expensive fluid loss additive, which does not adversely effect the rheological characteristics of the cementing composition or slurry.
SUMMARY OF THE INVENTION
This invention is directed to a cementing composition, which can be mixed with water to form an aqueous hydraulic cement slurry useful in, among other things, drilling operations, containing a hydraulic cement and, as a fluid loss control additive, water-soluble, nonionic hydrophobically modified hydroxyethyl cellulose (HMHEC). In a preferred embodiment both HMHEC and water-soluble, nonionic hydroxyethyl cellulose (HEC) are used as fluid loss control additives. This invention is also directed to the aqueous hydraulic cement slurry and to a process of using the aqueous slurry to fill the annulus between a borehole wall and a casing. In another aspect, this invention is directed to a composition comprising HMHEC and HEC which may be used, among other things, as a fluid loss agent for oil well casing cements.
DETAILED DESCRIPTION OF THE INVENTION
The polymers useful in this invention are well known water-soluble polymers Water-soluble, nonionic hydroxyethyl cellulose (HEC) is available commercially or can be prepared by known methods, such as by treating a cellulose furnish with ethylene oxide in an alkaline medium. Any cellulose furnish can be used, such as wood pulp or chemical cotton. Typically the cellulosic furnish has a degree of polymerization (D.P.) of from about 300 to about 2300.
The water-soluble, nonionic hydrophobically modified hydroxyethyl cellulose (HMHEC) of this invention may be prepared from HEC by chemically incorporating a long chain n-alkyl radical having 6 to 25, preferably 8 to 18 carbon atoms (hydrophobe), onto the HEC. The hydrophobe is attached to the cellulose via an ether or ester linkage, preferably an ether linkage. The amount of hydrophobe incorporated can vary from about 0.2 to about 4%, preferably about 0.2 to about 1.5%, most preferably 0.2 to 1.0%, based on the weight of the fully substituted polymer. The HMHEC of this invention has a hydroxyethyl molar substitution (M.S.) of at least about 1.5, preferably about 1.5 to about 4.0 (i.e., about 1.5 to about 4.0 moles of hydroxyethyl substitution per average anhydroglucose unit), and a relatively low to medium molecular weight (e.g., having a Brookfield viscosity in a 1% aqueous solution of about 300 to 500 cps at ambient temperature). The composition and preparation of the water-soluble HMHEC useful in this invention is described by Landoll in U.S. Pat. Nos. 4,228,227 and 4,352,916.
The HEC useful in combination with HMHEC per this invention has a hydroxyethyl M.S. of at least about 0.5, preferably about 1.0 to about 2.5, and most preferably 1.5 to 2.5 and relatively low to medium molecular weight (e.g., having a Brookfield viscosity of 25 to 250 cps in a 5% aqueous solution at ambient temperature).
Factors which affect cement slurry design include the type of cement and additives to be used, well temperature, mud-column pressure, viscosity and water content of cement slurries, pumping or thickening time, strength of cement required to support the pipe, quality of available water, slurry density, heat of hydration, permeability of set cement, filtration control, and resistance to down-hole brines. The HMHEC and HMHEC/HEC blends of this invention can be used under essentially the same conditions as HEC. Notably, excellent fluid loss properties, superior to those obtained with HEC, are obtained in shallow, intermediate and deep wells, but especially in intermediate depth wells at temperatures of from about 140° F. to about 225° F. A general description of the cementing composition and slurry follows.
The cementing composition of this invention may contain any of the known hydraulic cements, and, preferably, contains a portland cement based hydraulic cement such as API types A through H. The fluid loss additive or additives, i.e., the HMHEC or HMHEC and HEC, are contained in an amount of about 0.1 to about 2.0%, preferably from about 0.3 to about 0.5%, based on the total dry weight of the hydraulic cement.
The cementing composition is useful in all types of water generally encountered in drilling operations, i.e., fresh and tap water, natural and synthetic sea water, and natural and synthetic brine. The most commonly used sources of water are fresh water from rivers, lakes and streams when drilling on land and sea water when drilling in the ocean. The aqueous hydraulic drilling cement slurry of this invention generally contains about 40 to about 100% water, based on the dry weight of the hydraulic cement.
The hydraulic cement and fluid loss agent(s) may be dry blended to form a cementing composition and then added to water, or may be added directly to water. Similarly, when used in combination, the HEC and HMHEC may be dry blended prior to addition to the cementing composition or aqueous hydraulic cement slurry, or they may be added to the cementing composition or aqueous hydraulic cement slurry individually. In either event, when HEC and HMHEC are used in combination, they are contained such that each is present in an amount of 1 to 99%, preferably about 15 to about 85%, most preferably about 30 to about 70%, based on the total weight of the HEC and HMHEC.
Other polysaccharides and synthetic polymers may be used in combination with HMHEC or HMHEC and HEC in this invention. Exemplary are carboxymethyl cellulose, hydroxypropyl cellulose, methyl cellulose, methyl hydroxyethyl cellulose, carboxymethyl hydroxyethyl cellulose (CMHEC), hydroxypropyl methyl cellulose, ethyl hydroxyethyl cellulose, guar, hydroxypropyl guar, carboxymethyl guar, xanthan and acrylamide copolymers. They may be added to modify, among other things, rheological or fluid loss properties.
Other additives commonly employed in oil well casing cements can also be used in this invention. They include (a) cement accelerators such as calcium chloride, sodium chloride and sodium silicate, (b) light-weight additives (used to reduce the weight of the slurry) such as bentonite, diatomaceous earth, natural hydrocarbons such as gilsonite and coal, expanded perlite, nitrogen, fly ash and sodium silicate, (c) heavy weight additives such as hematite, ilmenite (iron-titanium oxide), barite, sand and salt, (d) cement retarders such as lignins (salts of lignosulfonic acid), gums, starches, weak organic acids, and cellulose derivatives such as CMHEC, (e) loss circulation control additives such as gilsonite, perlite, walnut shells, coal, cellophane and nylon, (f) cement dispersants or friction reducers including polymers, fluid-loss agents and salt (NaCl), (g) mud decontaminants such as paraformaldenyde and sodium chromate, (h) silica flour, (i) radioactive tracers, (j) indicator dyes, (k) hydrazine, (1) synthetic fibrous materials and (m) gypsum as described in, e.g., D. K. Smith, Cementing, cited above.
This invention is illustrated in the following example, which is not intended to be limiting. Therein, all parts, percentages, etc., are by weight unless otherwise indicated.
EXAMPLE
The polymers used in the example are summarized in the following Table 1.
TABLE 1______________________________________Polymers Hydrophobe ViscosityPolymer H.E.M.S..sup.1 Length Amount.sup.2 (cps)______________________________________HEC 1 2.5 -- -- 55.sup.3HEC 2 2.8 -- -- 90.sup.3HEC 3 2.5 -- -- 98.sup.3HEC 4 2.5 -- -- 76.sup.3HMHEC 1 3.13 C-16.sup.4 0.56.sup.5 440.sup.6HMHEC 2 3.29 C-16.sup.4 0.65.sup.5 360.sup.6______________________________________ .sup.1 Hydroxyethyl molar substitution. .sup.2 Percentage by weight, based on the total weight of the HMHEC. .sup.3 Brookfield viscosity measured in a 5% aqueous solution at ambient temperature. .sup.4 16 carbon atom nalkyl radical. .sup.5 Weight % as C.sub.16 (cetyl), based on the weight of the total polymer. .sup.6 Brookfield viscosity measured in a 1% aqueous solution at ambient temperature.
Testing was carried out according to American Petroleum Institute (API), "API Specification for Materials and Testing for Well Cements", API Spec 10, 1 st Edition, January 1982, except that filter paper was used on the screens for the fluid loss test.
Materials
The following components were used in the cements of the examples:
______________________________________1. API Class H cement consisting of: Composition: 50% tricalcium silicate (3 CaO.SiO.sub.2) 30% dicalcium silicate (2 CaO.SiO.sub.2) 5% tricalcium aluminate (3 CaO.Al.sub.2 O.sub.3) 12% tetracalcium aluminoferrite (4 CaO.Al.sub.2 Fe.sub.2 O.sub.3) Characteristics: Specific gravity (average) 3.15 gm/cm Surface area (range) 1400 to 1700 cm.sup.2 /g Bulk volume 1.06 × 10.sup.-2 ft.sup.3 /lb Absolute volume 3.81 × 10.sup.-2 gal/lb2. Water - distilled.3. Lomar D condensed sodium naphthalene sulfonate powder (sold by Diamond Shamrock) having the following characteristics:Apparent density 42/lbs/ft.sup.3pH (10% solution at 75° C.) 9.3Activity (amount of active agent) 84%Impurities:Na.sub.2 SO.sub.4 11%Moisture 5%4. Water Soluble Polymers: shown in Table 1 above.______________________________________
Equipment
______________________________________Equipment______________________________________1. N. L. Baroid 387 Filter Press (Baroid Filter Press).Operating pressure 0 to 2,500 psigOperating temperature 0 to 350° F.Cell volume 175 mlPower consumption 400 watts (115 v Ac)(heating chamber)Materials of construction stainless steelScreens 325 mesh on 60 mesh supportFilter paper (on screens) Baroid Catalog No. 9882. Chandler High Temperature, High Pressure Consistometer Model No. 7-1-15 (Chandler Consistometer).Operating pressure 0 to 25,000 psigOperating temperature 0 to 400° F.Power consumption 4000 watts (240 v Ac)(heating chamber)3. Chandler Engineering Constant Speed Mixer Model No. 30060-5 (Chandler Mixer).______________________________________
Slurry Preparation Procedure
A premixed dry blend of cement, polymer and Lomar D was added to the appropriate amount of distilled water (42%, based on the weight of the cement) stirred at 4,000 rpm over a period of 15 seconds in the Chandler Mixer. The resultant slurry was then shear blended in the Chandler Mixer at 12,000 rpm for 35 seconds.
Fluid Loss Test
While paddling, a slurry prepared according to the aforementioned procedures was poured into a pre-lubricated (silicon spray) consistometer cup until the material reached the fill line. Then, a potentiometer was placed on top of the cup and the cup was placed in the Chandler Consistometer. Heating was carried out according to the API temperature ramp schedule at 2° F per minute, with temperature measurements being taken every 2 minutes.
After the consistometer was heated to the final test temperature, the heated slurry was poured into a preheated fluid cell of the Baroid Filter Press (containing filter paper on screens) with paddling. Pressure lines were attached to the cell, and the upper and lower cell valves were opened to start the fluid loss test. Filtrate was collected in a graduate, with the filtrate level being recorded at 30 seconds, and 1, 2, 5, 10, 15, 20, 25 and 30 minutes. Whenever a sudden surge of pressure began blowing out the lower stem valve, the test was stopped and this was recorded as the time of dehydration. Otherwise the test was allowed to proceed for 30 minutes.
The final fluid loss value was calculated using the following equation:
Q.sub.+ =Q.sub.t ×10.954//t
where: Q 30 =Quantity of filtrate in 30 minutes (reported as final fluid loss).
Q t =Quantity of filtrate at time t.
t=Time in minutes when test ended (This value will be 30 minutes unless dehydration occurs, in which case it is the time of dehydration.).
Thickening Time Test
A slurry, prepared according to the above procedures, was poured into a pre-lubricated (silicon grease) cup and the cup was sealed, ensuring that there were no air pockets. The apparatus (Chandler Consistometer) was set up, with pressure and temperature slope being selected according to the API schedule. Heating was carried out, and temperature, pressure and consistency (DC voltage) were measured at 2 minute intervals during the heat up schedule and at 10 minute intervals thereafter. The test was carried out until the upper temperature (the test temperature listed in Table 2, below) was reached and terminated when the, DC voltage reached the point corresponding to 100 Bearden Units (Bc).
Free Water Test
A slurry, prepared according to the above procedures, was poured into the prelubricated (silicon grease) cup of the consistometer. The slurry was heated to the test temperature, poured into a graduated cylinder, clamped at a 45 degree angle, and allowed to set for 2 hours. The amount of water rising to the top of the cement column was recorded as the free water.
TABLE 2__________________________________________________________________________Results Of API Cement Test Initial Consistency Thickening Bc.sup.b (g) Fluid Loss (ml) (Set) Time.sup.c Free WaterPolymers.sup.a 0 min. 60 min. 140° F. 200° F. 225° F. 140° F. 200° F. 140° F. 200° F. 200° F.__________________________________________________________________________1. Control 1 - 100% HEC 1 -- 7 174 225 154.sup.d -- 6.3 hrs. 18 cc 20 cc --2. Control 2 - 100% HEC 2 -- 10 85 188 86.sup.d -- 5.6 hrs. 20 cc 18 cc (5.0%)3. Control 3 - 100% HEC 3 8 9 -- 92 -- -- -- -- 9 cc (2.5%)4. 80% HEC 4 - 20% HMHEC 1 -- 8 68 64 54.sup.d >8.0 hrs. 5.6 hrs. 22 cc 15 cc (4.2%)5. 67% HEC 4 - 33% HMHEC 1 -- 9 22 28 38.sup.d >8.0 hrs. 5.8 hrs. 12 cc 14 cc (3.9%)6. 33% HEC 3 - 67% HMHEC 2 18 17 -- 36 -- -- -- -- 6 cc (1.7%)7. 100% HMHEC 2 28 20 -- 30 -- -- -- -- 4 cc (1.1%)__________________________________________________________________________ .sup.a Concentrations used: 0.325% polymer, 0.325% Lomar D, and 42% water based on weight of cement. .sup.b Measured at room temperature. .sup.c Time to reach 100 Bc. .sup.d Fluid loss result which may be artificially low due to settling during the fluid loss test.
The above data show that HMHEC either alone (Sample 7) or in combination with HEC (Samples 4 through 6) provides fluid loss control in shallow, intermediate and deep well formations (the API defines wells by temperature: shallow =<140° F.; intermediate =140°-200° F.; and deep =>200° F.). In addition, it shows that HMHEC alone, or in combination with HEC, provides better fluid loss properties than HEC alone (Samples 1 through 3).
The above data show that cement initial consistency is higher with HMHEC (Sample 7) than HEC (Samples 1 through 3). The usual acceptable consistency range based on the pump-ability of cement is 5 to 30 Bearden units (Bc), preferably 10 to 12 Bc. The initial consistency of HMHEC (Sample 7) is acceptable at 28 Bc. However, use of HMHEC/HEC blends (Samples 4 through 6) appears preferable as they provide better initial consistency than HMHEC alone.
Free water volumes are better with HMHEC (Sample 7) than with HEC (Samples 1 through 3) or HEC/HMHEC blends (Samples 4 through 6).
While this invention has been described with respect to specific embodiments, it should be understood that these embodiments are not intended to be limiting and that many variations and modifications are possible without departing from the scope of this invention. | A novel cementing composition comprising a hydraulic cement and, as a fluid loss agent, water-soluble, nonionic hydrophobically modified hydroxyethyl cellulose, are disclosed. Preferably, the cementing composition further comprises water-soluble, nonionic hydroxyethyl cellulose as a second fluid loss agent. A novel aqueous slurry containing the cementing composition, a novel process of using the aqueous slurry to fill an annulus between a borehole wall and casing, and a novel composition of matter comprising specified amounts of water-soluble, nonionic hydrophobically modified hydroxyethyl cellulose and water-soluble, nonionic hydroxyethyl cellulose, are also disclosed. | 2 |
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This application claims benefit under 35 U.S.C. §119(e) to U.S. Provisional Application No. 61/528,592 entitled “Thermal insulation for Subsea Installations” filed Aug. 29, 2011, the contents of which are incorporated herein by reference in its entirety.
BACKGROUND
[0002] For subsea intervention operations, access to the well is gained by way of a production tube that is connected to a wellhead/christmas tree. Often, a riser is extended horn a wellhead to the ocean surface and the production tube is extended there through to the wellhead/christmas tree. An annulus is between the outside of the production tube and the inside of the riser. During intervention, flowback of well fluids can take place in the production tube. The well fluids are often hot and can be up to at least approximately 450° F.
[0003] For intervention a subsea test tree in connection with a subsea control module is integrated with the production tube and is used to control flow by way of various flapper and ball valves in the subsea test tree. The subsea control module can include accumulators. The accumulators can be pressure balanced accumulators. An accumulator is a device that stores potential energy. Often the potential energy is stored by way of compressed fluid, e.g., gas such as nitrogen or helium that transfers energy to a non-compressible fluid by way of a piston. The non-compressible fluid can be used to actuate tools by way of hydraulic, pressure. Valves (such as solenoid valves) can be used to control the output of the hydraulic fluid from the accumulator. Such solenoid valves can be controlled by a subsea electronics module. The subsea electronics module can be located proximate the subsea control module and integrated therewith. The subsea electronics module can also be located at surface and connect to the solenoid valves remotely. The subsea electronics module can receive signals electrically by wire, by acoustic transmission, by optical signals, or by pressure pulses.
[0004] Issues can arise with respect to deep water operations where ambient pressure is very high. In those cases the potential energy stored in the gas is less able to overcome the ambient pressure to perform the desired work. In those cases, pressure balanced accumulators can be used. Pressure balanced accumulators connect with the ambient pressure to exert pressure on the gas to compensate for the depth and ambient pressure.
SUMMARY
[0005] This summary is provided to introduce a selection of concepts that further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claims subject matter.
[0006] In general, a piping, system for housing system components for regulating the flow of fluid therethrough is provided. The piping system includes an inner small diameter length of piping through which hot fluids flow, an outer larger diameter length of piping surrounded by cold fluid, and an annulus between the small and larger diameter piping in which the system components are received. Insulation material extends about a predetermined section of the small diameter length of piping for restricting heat transfer therefrom to the system components in the annulus and allowing heat transfer from the system components in the annulus to the outer piping.
[0007] In another form, an offshore oil well installation is provided including, a production string extending in the ocean from to subsea well to a rig for flow of hot well fluid therethrough. A riser extends about the production string for isolated the production string from cold ocean water. An annulus is formed between the production string and the riser, and at least one temperature sensitive operating device is in the annulus. Examples of temperature sensitive operating devices can include, but are not limited to, electronics, gas chambers of accumulators, subsea batteries, and hydraulic and electrical jumpers made of thermoplastic materials. Insulation in the annulus between the production string and the riser insulates the temperature sensitive operating device from the heat generated by flow of hot well fluid in the production string and keeps the temperature sensitive operating device exposed to cooling generated by cold ocean water surrounding the riser.
[0008] In yet another form, a subsea control module for an offshore oil well installation is provided. The subsea control module has an inner mandrel. An outer riser receives the inner mandrel therein and is surrounded by ocean water. Operating devices are mounted to be disposed about and to extend along the inner mandrel. Insulation is secured to extend about and alone; the inner mandrel adjacent to the operating devices.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a schematic cross-sectional view of a prior subsea control module including accumulators thereof;
[0010] FIG. 2 is a schematic cross-sectional view of the prior subsea control module of FIG. 1 showing the temperature distribution in a section of the annulus in which a temperature sensitive operating device is disposed;
[0011] FIG. 3 is a schematic cross-sectional view of a subsea control module including insulation in the annulus in accordance with an embodiment herein;
[0012] FIG. 4 is a schematic cross-sectional view of the subsea control module of FIG. 3 showing the temperature distribution in a section of the annulus in which a temperature sensitive operating device is disposed;
[0013] FIG. 5 is an illustration of a subsea installation and an associated control system;
[0014] FIG. 6 is an illustration of a portion of a subsea test tree that can be used at the subsea installation;
[0015] FIG. 7 is a schematic illustration of a portion of the associated control system;
[0016] FIG. 8 is a schematic illustration of another portion of the associated control system;
[0017] FIG. 9 is a schematic illustration of another portion of the associated control system;
[0018] FIG. 10 is a schematic illustration of safety relevant parameters topside and subsea;
[0019] FIG. 11 is a schematic illustration of one example of the subsea control system incorporating a pressure balanced accumulator;
[0020] FIG. 12 is a cross-sectional view of one example of the pressure balanced accumulator illustrated in FIG. 11 ;
[0021] FIG. 13 is a cross-sectional view of an enlarged portion of the pressure balanced accumulator illustrated in FIG. 12 ;
[0022] FIG. 14 is a graph illustrating fluid volume expelled from the pressure balanced accumulator at different hydrostatic pressure levels;
[0023] FIG. 15 is a schematic illustration of a subsea installation having a subsea test tree and a subsea control assembly comprising a subsea control module and an interior mandrel; and
[0024] FIG. 16 is a view of one example of the subsea control assembly illustrated in FIG. 15 .
DETAILED DESCRIPTION
[0025] In the following description, numerous details are set forth to provide an understanding of the present application. However, it will be understood by those skilled in the art that the present invention may be practiced without many of these details and that numerous variations or modifications from the described embodiments are possible.
[0026] As used here, the terms “above” and “below”; “up” and “down”; “upper” and “lower”, “upwardly” and “downwardly”; and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly describe some embodiments of the invention. However, when applied to equipment and methods for use in wells that are deviated or horizontal, such terms may refer to a left to right, right to left, or diagonal relationship as appropriate.
[0027] Accumulators can be used to operate hydraulic tools in cases of emergencies. With that in mind, reliability can be of importance. Various factors can contribute to the longevity and reliability of an accumulator. One factor is temperature and temperature variations. For example, if the temperature rises to a level that was not planned for detrimental issues can result. Also, if the temperature of a tool varies greatly thermal stresses can result. Another factor is non-uniform temperatures. That is, a tool such as an accumulator's reliability can be compromised when one part of the tool is exposed to a different temperature than another part thereby creating uneven thermal expansion.
[0028] For subsea operations where accumulators (and pressure balanced accumulators) are used, while the sea water temperature is very predictable and stable at around 40° F., the temperature inside the annulus riser can increase dramatically during flowback and can frequently be as high as approximately 450° F. Flow back is a process of allowing fluids to flow from the well, either in preparation for a subsequent phase of treatment or in preparation for clean up and returning the well to production. The temperature variation in the in-riser annulus can have great impact on the functionalities and performance of mechanical and electrical tools located there. In the case of accumulators, thermal stresses can result and small tolerances can be affected due to thermal expansion. Delivery of hydraulic fluids through an umbilical can be impacted by high temperature by weakening the hydraulic hoses and reducing the life when the umbilical is clamped to the production tubing. For electrical devices (like circuit boards), due to the nature of the material that they are made of exposure to such high temperatures can be detrimental to longevity and performance. For mechanical tools, their performance may be de-rated or limited due to the temperature variations. The in-riser annulus is the radial space between the riser pipe and production pipe. This configuration is illustrated in FIG.
[0029] An objective of various embodiments in this application is to minimize the temperature changes and gradients experienced though the annulus due to flowback. Reducing spikes in the annulus temperature and reducing the temperature gradients will facilitate better performances of tools/devices for many in-riser applications. For accumulators used for the deep water control systems, insulation and reduction of a temperature gradient as described more fully hereinafter will lead to more uniform thermal exposure and reduction of the associated issues related to a high temperature gradient in the annulus. However, it should be understood that this application is not intended to be limited to the specific system components, devices or tools disposed in the annulus such as the accumulators described, herein. The present application relates to various embodiments that minimize the temperature variations due to the production pipe temperature increases by applying an insulation material such as a filament wound epoxy fiberglass composite material (or materials with similar properties, especially on thermal conductivity) as the thermal insulation media between the inner pipe and the tool.
[0030] According to another embodiment, to simply reduce the annulus temperature, it is possible to improve thermal exchanges between the outer part of the tool and its components by adding heat exchanging material to thermally conduct heat from the tool to the riser wall and which is in contact with the 40° F. sea water.
[0031] FIG. 1 shows a cross-section view of a subsea control system 200 . That arrangement includes inner, small diameter production pipe or piping string 202 , system components including temperature sensitive operating devices such as tools or actuators including accumulators 204 and a subsea electronics module (SEM) 206 , and the outer, larger diameter riser pipe or piping 208 . The environment temperature outside the riser pipe is that of sea water, which is relatively constantly at around 40° F. The temperature of the production pipe or inner pipe 202 varies and can be as high as approximately 450° F. due to flow back of well fluids. The annulus 210 between production pipe and riser pipe has a temperature profile that highly depends on the temperature of the cylindrical wall of the production pipe 202 . A temperature profile of the annulus 210 with production pipe 202 at approximately 300° F. is shown in FIG. 2 . The highest non-localized annulus temperature is approximately 250° F.
[0032] As is apparent, the extreme operating conditions created by the deep sea deployment of various control system operating components makes their efficiency and reliability a paramount concern. To this end, where the operation of these devices is temperature sensitive, locating these devices undersea in the annulus 210 having a widely varying temperature profile as shown in FIG. 2 can create challenges for their efficient and reliable operation. This wide temperature variation is exacerbated where the components have outer housings that are of heat conductive material such as the metal housing wall 204 a of the accumulators 204 . In this instance, it can be seen that the radially inner side of the accumulator cylindrical housing wall 204 a generally facing the hot inner production pipe 202 will draw heat creating local hot spots 211 a at this inner side of the accumulators 204 . On the other hand, the radially outer side of the accumulator housing wall 204 a will lose heat to the cold outer riser pipe 210 creating local cold spots 211 b at the accumulator outer side thus exacerbating the temperature gradient across the accumulator 204 in a radial direction, as can be seen in FIG. 2 . With pressure balanced accumulators, such extreme temperature variations from hot to cold can lead to variations in the volume of the gas charge which can degrade performance of these devices.
[0033] According to various embodiments, a thermal insulation layer 212 can be disposed between the production pipe 202 and the annulus 210 to insulate the system components such as the accumulators 204 and the SEM 206 in the annulus 210 from the high temperatures in the production pipe while at the same time keeping these components exposed to the cooling effect provided by the outer riser piping 208 due to the surrounding cold ocean water. FIG. 3 shows this arrangement. With the same or similar production pipe temperature, (approximately 300° F.), the thermal simulation results show that the highest annulus temperature is about 125° F., nearly 125° F. lower compared to the case without the thermal insulation (see a temperature distribution contour shown in FIG. 4 ). Additionally, the temperature gradient seen across the annulus 210 is improved.
[0034] The insulation 212 can substantially isolate the heat inside the production pipe 202 , thereby keeping the annulus temperature much lower than would be otherwise without the insulation 212 . This also improves the temperature gradient seen across the annulus 210 . Embodiments of this design have numerous benefits. For example, one benefit is keeping the heat away from any device in the annulus 210 . According, to some embodiments, the device can be an accumulator(s), and could be a pressure balanced accumulator(s). As can be seen in FIG. 4 , the temperature gradient across the accumulators 204 is more gradual from the inner slightly warmer side to the cooler outer side thereof as opposed to the more severe temperature gradient shown in FIG. 2 . As such, with the insulated piping system disclosed herein, the system components no longer need to be qualified for high temperature performance because of the harsh environment in the annulus 210 as depicted in FIG. 2 . Instead, standard or off-the-shelf components can now be used in the annulus 210 where the temperature variations are relatively minor due to the insulation 212 between the inner pipe 202 and the components disposed in the annulus 210 . Also, more particularly, the gas change used with pressure balanced accumulators will not be subjected to wide temperature fluctuations minimizing variations in the volume of the gas and thereby maintaining optimized performance of these devices.
[0035] Another aspect, for some situations, is to contain the heat which may be beneficial to the desired applications. The thermal insulation layer can be used to isolate the device from the cooling source. Also, the temperature gradient can be reduced across the annulus. Moreover, it should be noted that the insulation material is not limited to only the fiberglass composite material. Other materials with similar thermal conductivities can be suited for the intended applications and can serve the same or similar insulation purpose.
[0036] The filament-wound fiberglass epoxy composite material can be wrapped about the outer surface of the inner production pipe string 202 and bonded thereto by the epoxy. It is believed that the combination of tensile and flexural strength provided by the fiberglass epoxy composite insulation material will be sufficient to keep the insulation material secured to the production string 202 despite the flexing and tension loads to which the production piping string 202 is exposed. By way of example, at 300° F., the fiberglass epoxy composite has a tensile strength of approximately 345 MPa and a flexural strength of approximately 207 MPa.
[0037] Turning to more of the details of systems that can benefit from the piping system and insulated annulus thereof described herein, one such system is an overall subsea control system comprising a subsea test tree, such as a subsea test tree located within a riser, and an associated control. According to one embodiment, the subsea control system is a subsea wellhead control system comprising a subsea installation with an independently controlled subsea test tree. The subsea test tree comprises an upper portion separable from a lower portion and a plurality of shut-off valves. At least one shut-off valve is located in each of the upper portion and the lower portion.
[0038] Referring, generally to FIG. 5 a well system 20 is illustrated, according to one embodiment of the present invention. In the example illustrated, well system 20 is a subsea control system comprising a subsea installation 22 which includes a production control system 24 cooperating with a subsea test tree 26 . The subsea installation 22 is positioned at a subsea location 2 generally over a well 30 such as an oil and/or gas production well. Additionally, a control system 32 is employed to control operation of the production control system 24 and subsea test tree 26 . The control system 32 may comprise an integrated system or independent systems for controlling the various components of the production control system and the subsea test tree.
[0039] Although the production control system 24 and subsea test tree 26 may comprise a variety of components depending on the specific application and well environment in which a production operation is to be conducted, specific examples are discussed to facilitate an understanding of the present system and technique. The present invention, however, is not limited to the specific embodiments described. In one embodiment, production control system 24 comprises a horizontal tree section 34 having, for example, a production line 36 and an annulus line 38 , A blowout preventer 40 , e.g. a blowout preventer stack, may be positioned in cooperation with the horizontal tree section 34 to protect against blowouts. These components also comprise an internal passageway 42 to accommodate passage of tubing string components 44 and related components, such as a tubing hanger/running tool 45 .
[0040] The production control system 24 also may comprise a variety of additional components incorporated into or positioned above blowout preventer 40 . For example, at least one pipe ram 46 may be mounted in subsea installation 22 at a suitable location. In embodiment illustrated, two pipe rams 46 are employed. The system also may comprise at least one shear ram 48 , such as the two shear rams illustrated. Additionally, one or more, e.g. two, annular rams 50 may be employed in the system. The various production control systems 24 accommodate a riser 52 designed to receive subsea test tree 26 .
[0041] In the embodiment illustrated, the subsea test tree 26 comprises an upper portion 54 releasably coupled with a lower portion 56 via a connector 58 , such as a latch connector. The upper portion 54 and the lower portion 56 each contain at least one shut-off valve which may be selectively actuated to block flow of production fluid through the subsea installation 22 . The various components of subsea installation 22 are designed to allow an emergency shutdown. For example, subsea test tree 26 enables provision of a safety system installed within riser 52 during completion operations to facilitate safe, temporary closure of the subsea well 30 . The control system 32 provides, hydraulic power to the subsea test tree 26 to enable control over the shut-off valves. Control over the subsea test tree 26 may be independent of the safety functions of the production control system 24 , such as actuation of blowout preventer 40 .
[0042] The shut-off valves in subsea test tree 26 may range in number and design. In one embodiment, however, the upper portion 54 comprises a retainer valve 60 , as further illustrated in FIG. 6 , in the specific embodiment illustrated, lower portion 56 comprises a pair of valves in the form of a flapper valve 62 and a ball valve 64 . As desired for a given application, other components may be incorporated into subsea test tree 26 . For example, the upper portion 54 may comprise additional components in the form of a space out sub 66 , a bleed off valve 68 , and a shear sub 70 . Similarly, the lower portion 56 may comprise additional components, such as a ported joint 72 extending down to tubing hanger 46 .
[0043] The shut-off valves may be controlled electrically, hydraulically, or by other suitable techniques. In the embodiment illustrated, however, valves 60 , 62 , 64 are controlled hydraulically via hydraulic lines 74 . For example, the position of the valves 60 , 62 , 64 may be controlled via a combination of opened or closed directional control valves 76 located in, for example, a subsea control module 78 . The directional control valve 76 control whether hydraulic pressure is present or vented on its assigned output port in the subsea test tree. The directional control valves 76 within subsea control module 78 may be controlled via solenoid valves or other actuators which may be energized via electrical signals sent from the surface. Accordingly, the overall control system 32 for controlling subsea test tree 26 may have a variety of topside and subsea components which work in cooperation.
[0044] During a specific valve operation, an operations engineer may issue a command via a human machine interface 80 of a master control station 82 , such as a computer-based master control station. In some applications, the master control station 82 comprises or works in cooperation with one or more programmable logic controllers. Electric current is sent down through an umbilical 84 to the solenoid valves and subsea control module 78 to actuate directional control valves 76 . The umbilical 84 also may comprise one or more hydraulic, control lines extending down to the subsea control module from a hydraulic power unit 86 . In the embodiment illustrated in FIGS. 5 and 6 , the hydraulic lines 74 also are routed to an accumulator 88 , such as a subsea accumulator module.
[0045] When a desired directional control valve 76 is opened, hydraulic pressure supplied by hydraulic power unit 86 is passed through its assigned output port to the subsea test tree 26 . Conversely, when a directional control valve 76 is closed, any hydraulic pressure present at its output port is vented. Hydraulic power is transferred from the subsea accumulator module 88 to a particular valve 60 , 62 , 64 located in the subsea test tree 26 . The designated valve transitions and fulfills the intended safety instrumented function for a given situation.
[0046] An emergency shutdown sequence may be achieved through a series of commands sent to one or more of the valves 60 , 62 and 64 . The emergency shutdown sequence may be designed to bring the overall system to a safe state upon a given command. Depending on the specific, application, the emergency shutdown sequence also may control transition of additional valves, e.g. a topside production control valve, to a desired safety state.
[0047] If a complete loss of communication between the topside and subsea equipment occurs, i.e. loss or severing of the umbilical 84 , the directional control valves 76 are designed to return to a natural or default state via, for example, spring actuation. This action automatically brings the well to a fail safe position with the topside riser and the well sealed and isolated. If the topside equipment is unable to bring the well into a safe state, then the operator can institute a block-and-bleed on the hydraulic power unit 86 to cause the subsea test tree to transition into its failsafe configuration. Additionally, visual and/or audible alerts may be used to alert an operator to a variety of fault or potential fault situations.
[0048] In the specific example illustrated in FIG. 6 the subsea test tree 26 has four basic functions utilizing retainer valve 60 , connector 58 , flapper valve 62 , and ball valve 64 . The retainer valve 40 functions to contain riser fluids in riser 52 after upper portion 54 is disconnected from lower portion 56 . The connector 58 , e.g. latch mechanism, enables the riser 52 and upper portion 54 to be disconnected from the remaining subsea installation 22 . The flapper valve 62 provides a second or supplemental barrier used to isolate and contain the subsea well. Similarly, the ball valve 64 is used to isolate and contain the subsea well as a first barrier against release of production fluid.
[0049] The subsea test tree 26 may be used in a variety of operational modes. For example, the subsea test tree 26 may be transition to a “normal mode”. In this mode, a standard emergency shutdown sequence may be used in which a ball valve close function is performed to close ball valve 64 . By way of example, the ball valve 64 may be closed by supplying hydraulic fluid at a desired pressure, e.g. 5 kpsi. Another mode is employed as the subsea test tree system is run in hole or pulled out of hole (RIH/POOH mode). In this mode, the valve functions are disabled to prevent a spurious unlatch at connector 58 while the assembly is suspended in riser 52 . In another example, the system is placed in a “coil tubing” mode when coil tubing is present in riser 52 while a disconnect is to be initiated. In this mode, the ball valve is actuated under a higher pressure, e.g. 10 kpsi, to enable severing of the tubing via, for example, shear rams 48 .
[0050] The control system 32 also may be designed to operate in a diagnostic mode. The diagnostic mode is useful in determining the integrity of the signal path as well as the basic functionality of the subsea control module, including the solenoid valves and directional control valves. In this mode, a selected current, e.g. a 30 mA current, is delivered down each of the electric lines, e.g. seven lines, within umbilical 84 . Then, by verifying the voltage required to drive this current, the impedance of the system can be inferred. This current is insufficient to trigger a solenoid into actuation, but the current may be used to verify various operational parameters. Examples of verifying operational parameters include: verifying delivery of power to the system from an uninterruptible power supply; verifying the solenoid driver power supply is functional; verifying performance of a programmable logic controller; verifying that all connectors are intact; and verifying solenoids have not failed in an open or shorted manner. The diagnostic testing can be performed on command from a SCADA, or as a self-diagnostic function at pre-determined time intervals depending on results of a hazard and operability application.
[0051] Referring, generally to FIGS. 7-9 , a variety of subsea control system functions/implementations are illustrated via schematic block diagrams. In the embodiment illustrated in FIG. 7 , for example, control system 32 utilizes a surface based master control system 82 comprising a programmable logic control system 90 to isolate topside flow output via a production wing valve 92 . The wing valve 92 may comprise a master valve, a downhole safety valve, or another wing valve operated by the production control system. By way of example, the overall system may be designed at an SIL3 level while the subsea test tree employed in the subsea installation 22 is at an SIL2 level.
[0052] In the embodiment illustrated in FIG. 7 , the topside wing valve 92 is operated by a high pressure system through a solenoid actuated valve 94 controlled via programmable logic controller 90 in master control system 82 . The valve 94 is considered to be in a safe state when it is in its closed position. To avoid, problems if programmable logic controller 90 fails to actuate the valve when desired, the system may be designed to enable manual triggering of the valve. Verification that wing valve 92 has been actuated can be based on select parameters. For example, the verification may be based on detection of actuation current delivered by the master control system; detection of the actuation voltage required to achieve the desired current (implied impedance); and/or operator verification of the position of the wing valve via an appropriate gauge or sensor.
[0053] In the specific example illustrated, programmable logic controller 90 is coupled to an emergency shutdown panel 96 . Additionally, the programmable logic controller 90 comprises an input module 98 , a logic module 100 , and an output module 102 . The programmable logic controller 90 may be powered by an uninterruptible power supply 104 , and the output module 102 may be independently coupled to a power supply unit 106 . The output module 102 controls actuation of solenoid valve 94 which, in turn, controls delivery of hydraulic actuation fluid to wing valve 92 . Additional components may be positioned between solenoid valve 94 and wing valve 92 to provide an added level of control and safety. Examples of such components comprise a supplemental valve 108 and an air block 110 .
[0054] A similar control technique may be used to control actuation of retainer valve 60 in upper portion 54 , as illustrated in FIG. 8 . In this example, the emergency shutdown sub function begins at the master control system 82 where the demand is initiated, however the function does not include other initiating factors. The function concludes with the retainer valve 60 closing with respect to riser 52 . An appropriate SIL level for this sub-function may be SIL2. Verification that retainer valve 60 has been actuated to a closed position can be based on select parameters. For example, the verification may be based on detection of actuation current delivered by the master control system; detection of the actuation voltage required to achieve the desired current (implied impedance); detection of flow as measured by flow meters on the hydraulic power unit 86 ; and/or measuring a pressure response with transducers on the subsea accumulator module 88 .
[0055] Another control technique/sub-function is used to isolate subsea well 30 via the shut-off valves, e.g. valves 62 , 64 , in the lower portion 56 of subsea test tree 26 , as illustrated in FIG. 9 . In this specific example, two shut-off valves are utilized for the sake of redundancy in the form of flapper valve 62 and ball valve 64 , however one valve is sufficient to leave the subsea well 30 in a safe state. In this example, the emergency shutdown sub-function begins at the master control system 82 where the demand is initiated, however the function does not include other initiating factors. The function concludes with the flapper valve 62 and/or ball valve 64 closing with respect to subsea well 30 . An appropriate SIL level for this sub-function may be SIL2. Verification that at least one of the flapper valve 62 and ball valve 64 has been actuated to a closed position can be based on select parameters. For example, the verification may be based on detection of actuation current delivered by the master control system; detection of the actuation voltage required to achieve the desired current (implied impedance); detection of flow as measured by flow meters on the hydraulic power unit 86 ; and/or measuring a pressure response with transducers on the subsea accumulator module 88 .
[0056] The safety integrity levels (SILs) described herein are not necessarily derived from a risk-based approach for determining SIL levels as described in standard IEC61508, instead, the SIL levels sometimes are based on industry recognized standards for production system safety functions. Based on the minimum SIL requirements for each function as applies to the existing, layers of protection, the minimum SIL level for the various safety integrity functions, e.g. the sub-functions outlined in FIGS. 3-5 , may be selected as SIL2.
[0057] Additionally, the subsea test tree 26 and its corresponding shut-off valves 60 , 62 , 64 may be operated completely independently with respect to operation of the production control system 24 which is used during normal operations. In this case, the overall control system 32 may comprise completely independent control systems for the subsea test tree 26 and the production control system 24 . The subsea test tree 26 may be installed within the production control system 24 , e.g. inside a Christmas tree, during operation inside the blowout preventer stack 40 . In the event that the blowout preventer 40 is required to close, the subsea test tree 26 is sealed and disconnected from the string (separated at connector 58 ). This allows the upper portion 54 of the subsea test tree 26 to be retracted so the blowout preventer rams can be closed without interference.
[0058] If the upper portion 54 cannot be unlatched and retracted during a subsea test tree failure mode, the shear rams 48 may be operated to sever the tool and safely close the well. The blowout preventer control system has no influence on the safety functions of the subsea test tree system. One example of a dosing pattern comprises closing the upper retainer valve 60 , followed by closure of the lower ball valve 64 and subsequent closure of the flapper valve 62 . Once the upper production string is sealed via retainer valve 60 and access to the wellbore is sealed via ball valve 64 and flapper valve 62 , the subsea test tree is disconnected and separated at connector 58 .
[0059] Specific safety relevant parameters may be selected according to the system design, environment, and applicable requirements in a given geographical location. However, one example of a typical approach is illustrated in FIG. 10 as having a safe failure fraction exceeding 90% on the topside for a Type B safety system (complex) and a hardware fault tolerance of zero, per standard IEC61508-2. At the subsea location, the system comprises a Type A subsystem having a safe failure fraction greater than 60% and a hardware fault tolerance of zero. Final elements on the topside may be evaluated to the DC fault model per IEC61508-2 (fault stuck at Vcc and stuck at Gnd, as well as stuck open and stuck shorted). Final elements in the subsea portion of the system are evaluated as a Type A system because only discrete passive components are used. All failure modes of these components are well defined and sufficient field data exists to be able to assume all fault conditions.
[0060] The accumulator module 88 may be incorporated into the overall system in a variety of configurations and at a variety of locations. In one example, accumulator module 88 is as pressure balanced accumulator to provide hydraulic power to the system in case of emergency closure and disconnect and/or loss of hydraulic power from the surface.
[0061] Accumulators are devices that provide a reserve of hydraulic fluid under pressure and are used in conventional hydraulically-driven systems where hydraulic fluid under pressure operates a piece of equipment or a device. The hydraulic fluid is pressurized by a pump that maintains the high pressure required.
[0062] If the piece of equipment or the device is located a considerable distance from the pump, a significant pressure drop can occur in the hydraulic conduit or pipe which is conveying the fluid from the pump to operate the device. Therefore, the flow may be such that the pressure level at the device is below the pressure required to operate the device. Consequently, operation may be delayed until such a time as the pressure can build up with the fluid being pumped through the hydraulic line. This result occurs, for example, with deep water applications, such as with subsea test tree and blowout preventer equipment used to shut off a wellbore to secure an oil or gas well from accidental discharges to the environment. Thus, accumulators may be used to provide a reserve source of pressurized hydraulic fluid for this type of equipment. In addition, if the pump is not operating, accumulators can be used to provide a reserve source of pressurized hydraulic fluid to enable the operation of a piece of equipment or device.
[0063] Accumulators may include a compressible fluid, e.g., gas, nitrogen, helium, air, etc., on one side of a separating mechanism, and a non-compressible fluid (hydraulic fluid) on the other side. When the hydraulic system pressure drops below the precharged pressure of the gas side, the separating mechanism will move in the direction of the hydraulic side displacing stored hydraulic, fluid into the piece of equipment or the device as required.
[0064] When some types of accumulators are exposed to certain hydrostatic pressure, such as the hydrostatic, pressure encountered in subsea operations, the available hydraulic fluid is decreased since the hydrostatic pressure must first be overcome in order to displace the hydraulic fluid from the accumulator. However, pressure balanced accumulators may be employed to overcome the above-described shortcomings. Examples of pressure-balanced accumulators are disclosed in U.S. Pat. No. 6,202,753 to Benton and U.S. Patent Publication No. 2005/0155658-A1 to White.
[0065] Referring, generally to FIG. 11 , an example of one implementation of accumulator module 88 is illustrated. In this example, accumulator module 88 is a pressure balanced accumulator system. The accumulator system 88 is connected with the one or more hydraulic lines 74 routed between hydraulic power unit 86 and subsea test tree 26 . Hydraulic, power unit 86 may comprise one or more suitable pumps 110 far pumping hydraulic fluid. The hydraulic power unit 96 is located above a sea surface 111 and provides control fluid for the operation of, for example, blowout preventer 40 and the valves 60 , 62 , 64 of subsea test tree 26 . The pressurized hydraulic fluid from hydraulic power unit 86 also is used to charge the pressure balanced accumulator system 88 . By way of example, the hydrostatic pressure P.sub.HS supplied by pump 110 is approximately 7500 psi, although other pressure levels may be used.
[0066] Referring generally to FIGS. 12 and 13 , one embodiment of a pressure balanced accumulator 88 is illustrated. The illustrated embodiment is readily utilized in conjunction with subsea test tree 26 , production control system 24 , and control system 32 . As illustrated, the pressure balanced accumulator 88 comprises a housing 112 , which is a generally tubular-shaped member having two ends 114 and 116 . An accumulator mechanism 118 is located within the housing 112 proximate the first end 114 . The accumulator mechanism 118 comprises a first chamber 120 (see FIG. 13 ) for receiving a pressurized gas at a first pressure. The pressurized gas may, for example, be injected into chamber 120 through gas precharge port 122 . In one embodiment of the present invention, the gas in the first chamber 120 is helium, and it is pressurized to approximately 3500 psi, although other pressures may be used depending, on the specific application.
[0067] With further reference to FIGS. 12 and 13 , accumulator mechanism 118 also comprises a second chamber 124 for receiving a first pressurized fluid at a second pressure. The pressure of the fluid in chamber 124 is sometimes referred to as the “gauge pressure.” In one embodiment, liquid may be injected into chamber 124 via a seal stab port 126 . The liquid injected into chamber 124 may be in the form of a water glycol mixture according to one embodiment of the present invention. By way of example, the mixture may be injected into chamber 124 at a pressure of approximately 5000 psi, although other pressures may be utilized in other applications. Chambers 120 and 124 are hermetically sealed from one another at regions 128 and 130.
[0068] The pressure balanced accumulator system 88 may further comprise a third chamber 132 which abuts accumulator mechanism 118 in housing 112 . Third chamber 132 contains a fluid, which may be injected into chamber 132 via fluid fill port 134 . In one embodiment, the fluid injected into third chamber 132 is silicon oil, which is selected for use because of its lubricity and because it will not adversely affect seals 136 deployed to seal along one end of chamber 132 . Initially, the silicon fluid is not injected into third chamber 132 under pressure. In operation, however, the pressure of the fluid in chamber 132 tracks the pressure of the fluid in second chamber 124 , as described below.
[0069] Pressure balanced accumulator 88 also comprises a piston 138 which is located within the housing proximate the second end 116 of housing 112 . The piston 138 has a first end 140 and a second end 142 which have first and second cross-sectional areas, respectively. In one embodiment, the cross-sectional areas of piston ends 140 and 142 are circular in shape. Piston 138 is movable between a first position, as shown in FIG. 12 , and a second position in which piston end 140 is stopped by a shoulder 144 .
[0070] Housing end 116 also may comprise an ambient pressure port 146 . When pressure balanced accumulator 88 is used in a subsea environment, ambient pressure port 146 permits the ambient subsea pressure to impinge on end 140 of piston 138 .
[0071] In the illustrated embodiment, pressure balanced accumulator system 88 also comprises an atmospheric chamber 148 which includes an annular recess 150 formed between piston 138 and the wall of housing 112 ; an axial cavity 152 which is formed by hollowing out a portion of piston 138 ; and a passage 154 connecting annular recess 150 and axial cavity 152 . This atmospheric chamber allows differential pressure to exist across piston 138 which enables the piston to start to move when an equilibrium pressure exists across piston 138 as discussed below. In one embodiment, the pressure in the atmospheric, chamber is 14.7 psi, the volume of annular recess 150 is approximately 10 in.sup.3, and the volume of axial cavity 152 is approximately 200 in.sup.3.
[0072] In subsea applications, such as the subsea applications described above, accumulator module 88 may be located in a subsea environment to control the operation of an in-riser or open water intervention system, such as subsea test tree 26 and associated valves 60 , 62 , 64 . The first and second chambers 120 and 124 in accumulator mechanism 118 of pressure balanced accumulator system 88 are precharged prior to placement of pressure balanced accumulator system 88 in the subsea environment. Pump 110 , which is located above the sea surface 111 , provides the control fluid for the operation of blowout preventer 40 and shut-off valves 60 , 62 , 64 . The pump 110 also provides a charging input to second chamber 124 of accumulator mechanism 118 in pressure balanced accumulator system 88 .
[0073] For purposes of illustration, it can be assumed that the hydrostatic pressure, P.sub.HS, in which pressure balanced accumulator 88 is operating is 7500 psi, although other pressures may be employed. This ambient pressure is communicated through ambient pressure port 146 of accumulator system 88 and impinges on end 140 of piston 138 . The force acting on piston 138 at its end 140 is given by the formula.
[0000] F.sub.1-P.sub.HS.times.(the area of piston end 140 ). (1)
[0000] The force on end 142 of piston 138 is given by the formula:
[0000] F.sub.2=(P.sub.HS+5000).times.*the area of piston end 142 ). (2)
[0074] In one specific example of the present invention, piston ends 140 and 142 are circular in cross-section and have cross-sectional areas established by diameters of 3.375 inches and 2.688 inches, respectively, although the sizes are for purposes of explanation only. At the hydrostatic pressure of 7500 psi, the equilibrium pressure, P.sub.E, at which the piston 138 starts to move is:
[0000] P E=7500(3375. 2.688)2=11,824 lbf(3)##EQU100001##
[0075] The gauge pressure P.sub.G at which the piston begins to move is given by the formula:
[0000] P.sub.G=P.sub.E-P.sub.HS-11,824-7,500P.sub.G=4,324 psi (4)
[0076] In accordance with the present invention, the diameter of piston ends 140 (D.sub.1) and 142 (D.sub.2) may be sized for optimal efficiency at a predetermined hydrostatic pressure, using the following formula:
[0000] D1=(P HS+P C−S)P HS D2·#EQU3000014##
[0000] where P.sub C is the pressure to which the second chamber of accumulator mechanism 118 is charged, e.g., 5000 psi, and S is a hydraulic safety factor which is an allowance given to prevent instability in maximum hydrostatic conditions. For a hydrostatic pressure of 7500 psi, S is approximately 500 psi. If D.sub.2=2.688 inches as in the above calculation with respect to equations (3) and (4) then D.sub.4 according to equation (5) is 3.40 inches.
[0077] In FIG. 14 , a graph is presented with a graph line 156 provided to illustrate the fluid volume of fluid expelled from the accumulator mechanism 118 at a hydrostatic pressure of 7500 psi and with D.sub.1 and D.sub.2 being 3.375 inches and 2.688 inches, respectively. Graph lines 158 , 160 and 162 illustrate fluid volume expelled at hydrostatic pressures of 6500, 5500 and 4500 psi, respectively.
[0078] In certain embodiments, the control system 32 may comprise a subsea control assembly 164 to control the subsea test tree 26 located in the blowout preventer 40 of subsea installation 22 . As illustrated schematically in FIG. 15 , the subsea control assembly 164 may be connected into an overall pipe string 166 extending down through riser 52 . The previously-described insulation 212 can be used along sections of the pipe string 166 wherever temperature sensitive components or devices are located in the annulus. For example, the subsea control assembly 164 may be connected in line between the subsea test tree 26 and a landing string pipe 168 of the overall pipe string 166 . It should further be noted that the subsea control assembly 164 also may be employed to control various other devices below the subsea installation 22 and/or devices integrated with completion components below the subsea test tree 26 . By way of example, the subsea control assembly 164 may be employed to control valves, sensors, actuators, latches, and other devices.
[0079] The subsea control assembly 164 may be formed with a subsea control module 170 mounted around an internal, mandrel 172 . This allows the subsea control assembly 164 to become an integral part of an internal pressure and load bearing landing string. The subsea control assembly 164 may be constructed as a single lift, multicomponent unit. For example, the subsea control module 170 may be constructed with a plurality of sections which are slid over and locked to mandrel 172 , which is a central, pressure containing, load bearing mandrel. The sections of subsea control module 170 may be connected via hydraulic and electrical jumpers. In this example, the mandrel 172 comprises a central pipe 174 having end hubs 176 , 178 for connection with the subsea test tree 26 and the landing string pipe 168 , respectively. In this instance, the insulation 212 can be secured to extend about and along the pipe 174 to be integrated with the subsea control module 170 , as shown in FIG. 15 .
[0080] One embodiment of the subsea control assembly 164 is further illustrated in FIG. 16 . In this embodiment, the subsea control module 170 is mounted around mandrel 172 and comprises a plurality of sections 180 . The sections 180 may be integrally formed and mounted around mandrel 172 , or the sections 180 may be individually slid over mandrel 172 , locked to the mandrel, and coupled to each other as necessary. For example, hydraulic and electrical connections may be formed with hydraulic and electrical jumpers between the plurality of sections 180 .
[0081] In the particular example illustrated, the plurality of sections 180 forming subsea control module 170 comprises an upper section having at least one accumulator, e.g. accumulator 88 , a hydrostatic pressure/temperature compensator 182 (e.g., volume compensator), and a subsea electronics module 184 . The upper section 180 is coupled to a lower section comprising a hydraulic, valve manifold pod 186 . By way of example, the at least one accumulator 88 may comprise a plurality of the accumulators, such as the five pressure-balance accumulators, illustrated as deployed around mandrel 172 . Depending on the application, the accumulators may be used to store hydraulic fluid at or up to a desired pressure, e.g. 7500 psi, above hydrostatic while at the subsea location. The insulation 212 may extend between the mandrel 172 , and specifically on the pipe 174 thereof, and the pressure-balanced accumulators 88 disposed thereabout.
[0082] The subsea electronics module 184 receives electronic signals from the topside master control system 82 and operates appropriate valves 188 , e.g. solenoid operated valves 94 and/or directional control valves, of hydraulic valve manifold pod 186 . As described above, the solenoid operated valves 94 may be used to direct hydraulic fluid to the desired subsea actuators used to actuate valves 60 , 62 , 64 or other subsea components. The hydraulic, valve manifold pod 186 may be constructed with hydraulic. Manifolds containing the solenoid operated valves and directional control valves. Additionally, the hydraulic valve manifold pod may comprise filters, relief valves, and other components mounted within an oil-filled pressure compensated enclosure. The pressure compensation may be provided by the hydrostatic pressure/temperature compensator 182 . Again, insulation 212 can be secured to the section of the mandrel pipe 174 extending along the subsea electronics module 184 and the hydraulic manifold pod 186 .
[0083] The one or more sections 180 of subsea control module 170 are designed to allow removal and replacement of mandrel 172 . Accordingly, the overall subsea control assembly 164 enables use of an interchangeable mandrel. In some embodiments, for example, the plurality of sections 180 is designed to enable use of mandrels having differing diameters such that the internal mandrel 172 may be interchanged with another mandrel having a larger and/or smaller diameter. As a result, the subsea control assembly 164 may be constructed as a modular assembly in which the mandrel 172 and the control module sections 180 are interchangeable. In one specific example, this allows the mandrel 172 to be interchanged to enable operation of the subsea control module at different operating bore pressures, e.g. 10,000 psi or 15,000 psi operating bore pressures. As a result, the subsea control module 170 is not affected by the bore pressure or contents and thus can be adapted to a variety of bore pressures by interchanging mandrels.
[0084] For special applications and/or to meet specific client requirements, the mandrel 172 is easily changed to accommodate custom pressures and/or materials. This allows one universal subsea control module 170 to be used for a wide range of existing and future well conditions. The mandrel 172 also may be designed with a variety of connector mechanisms at its hubs 176 , 178 to accommodate easy connection into the pipe string 166 . By way of example, hubs 176 , 178 may utilize premium thread connections 190 for make-up to the adjacent tool hubs at either end of the subsea control assembly 164 . The end connections and the interchangeability of mandrel 172 also allow the mandrel to be easily removed for periodic inspection and recoating. Inspection and recoating promotes system longevity by preventing corrosion otherwise caused by wellbore fluids and external completion fluids encountered in deep offshore wells.
[0085] The overall subsea control system 20 may be designed for use in a variety of well applications and well environments. Accordingly, the number, type and configuration of components and systems within the overall system may be adjusted to accommodate different applications. For example, the subsea test tree may include different numbers and types of shut-off valves as well as a variety of connectors, e.g., latch mechanisms, for releasably connecting the upper and lower parts of the subsea test tree. The production control system also may comprise various types and configurations of subsea installation components. Similarly, the control system 32 may rely on various topside and subsea components which enable independent control over the subsea test tree and the blowout preventer. For example, subsea control assemblies may be designed for integration into the pipe string with an interchangeable mandrel and a variety of control module sections selected according to the specific well application.
[0086] in some applications, the control system utilizes surface components which are computer-based to enable easy input of commands and monitoring of subsea functions. As described above, programmable logic controllers also may be employed and used to carry out various sub-functions implemented in emergency shutdown procedures. Various adaptations may be made to accommodate specific environments, types of well equipment, applicable standards, and other parameters which affect a given subsea well application.
[0087] Although only a few embodiments of the present invention have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this invention. Accordingly, such modifications are intended to be included within the scope of this invention as defined in the claims. | A piping system for housing system components for regulating the flow of fluid therethrough is provided. The piping system includes an inner small diameter length of piping through which hot fluids flow, an outer larger diameter length of piping surrounded by cold fluid, and an annulus between the small and larger diameter piping in which the system components are received. Insulation material extends about a predetermined section of the small diameter length of piping for restricting heat transfer therefrom to the system components in the annulus and allowing heat transfer from the system components in the annulus to the outer piping. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates in general to a conveyor system and in particular to an automatic sorting conveyor system which can be arranged in any desired loop configuration and which is capable of automatically and arbitrarily sorting a variety of articles of various sizes being transported.
In a hithertofore known automatic conveyor system, a plurality of single-sheet trays of a size corresponding to that of the articles to be transported has been employed to form an endless conveyor with each of trays being supported tiltably on a bogie having four wheels and locked normally in an untiltable position. The bogies are connected to an endless chain so as to form the endless loop conveyor. Such conventional conveyor system has, however, many drawbacks. For example, in the running of the bogies having four wheels but provided with no differential gear mechanism, there may be slippage between the inside and outside wheels due to a difference in speed therebetween when the bogies are running at a curved portion of the conveyor track. For this reason, restriction is imposed to the curvature of the curved portion of the track in dependence on the size of the bogies as employed and the speed at which they are to run. Additionally, because the conveyor chain used for the coupling of the bogies in the hitherto known conveyor are not of the universal type, the bogie can not run on the track having different vertical levels in the extension thereof, since the coupling chain is not able to bend in the vertical direction. Further, complex and expensive structures are required because of the necessity of the tilting and the locking mechanisms.
SUMMARY OF THE INVENTION
An object of the present invention is, therefore, to eliminate the disadvantages of the conventional conveyor system as above mentioned. To this end, the invention contemplates a novel structure of a conveyor system in which a transporting or carrier structure composed of plural sheets of slats disposed with their end portions being partially superposed to one another are connected to an endless conveyor chain in a loop-like fashion which has links connected to one another through cross pins so that the chain may be bent universally in any direction. Thus, there is provided in accordance with the present invention an improved automatic sorting conveyor system which can employ a conveyor track of a closed loop configuration having curved portions of small curvature and differences in the vertical level and which is provided with carrier or transporting structures each having a simple and reliable tilting and switching mechanisms.
The above and other objects and advantages of the invention will become more apparent from the following detailed description made with reference to the accompanying drawings which show a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic perspective view showing generally an embodiment of the automatic sorting system according to the invention;
FIG. 2 is a side view showing one of carrier structures employed in the conveyor system;
FIG. 3 is a perspective view of the carrier structure with some portions broken away for clarity;
FIG. 4 is a sectional view taken along the line 4--4 in FIG. 3;
FIG. 5 is a sectional view taken along the line 5--5 in FIG. 3;
FIG. 6 is a side elevational view of a switching apparatus shown with portions broken away;
FIG. 7 is an end view of the switching apparatus with some portions shown in section;
FIG. 8 is a perspective view showing a tilted carrier and the switching mechanism with some portions broken away; and
FIG. 9 is a perspective view illustrating the resetting of the tilted carrier structure at the restoring station.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, reference numeral 1 generally indicates a conveyor system according to the present invention which comprises a plurality of supporting legs 11, a frame structure 12 constructed in a desired loop configuration and fixedly secured at a desired height by means of the supporting legs 11, a guide rail structure 14 extending substantially along the longitudinal axis of the supporting frame 12, a plurality of transporting or carrier structures 15 connected to one another in an endless fashion and adapted to be guided by the guide rail 14, and a driving apparatus 16 for driving the carrier structures 15. It will be noted that the supporting frame 12 is stationally disposed so as to form a desired planar closed loop at a predetermined adjustable height by the height-adjustable supporting legs 11 in compliance with the height of a standby conveyor 2 installed at a loading station where articles 3 to be transported and sorted are loaded onto the conveyor 1 as well as the vertical level of sorting chutes 4 at sorting stations. The guide rail structure 14 comprises a center rail 22 (FIGS. 3-9) secured to the supporting frame 12 and extending along the longitudinal axis thereof and a pair of lateral rails 24 disposed at both sides of the center rail 12 spaced therefrom.
Each of the carrier structures 15 is adapted to run along the guide rail structure 14 and to be tilted at desired stations. The carrier structures each include plural sheets of slats 25 (four sheets in the illustrative embodiment in a nonrestrictive sense) which are supported by supporting mechanisms 26, 27, 28 and 29 with the end portions of the slats being partially superposed over one another. The conveyor belt constructed by a plurality of groups each comprising plural sheets of these slats 15 is driven by a driving apparatus 16 in the direction indicated by arrows. The driving apparatus 16 is composed of an electric motor 17 and a drum 18 rotatably driven by the motor 17 and having a spiral groove 19 formed in the peripheral surface thereof. One of wheels 34 of a conveyor chain 31 coupling the carrier structures 15 in the endless manner is engaged in the groove 19 of the drum 18 whereby the conveyor chain and hence the carrier structures are driven forwardly upon the rotation of the drum 18.
In the operation of the automatic sorting conveyor system shown in FIG. 1, when the unloaded or idle carrier structure 15 approaches the standby conveyor 2 on which the articles 3 to be transported and sorted rest, a control apparatus (not shown) is supplied with a command signal from a destination command apparatus 6 provided in the vicinity of the standby conveyor 2, thereby to drive the latter to transfer the articles onto the carrier structure 15. At this time, the control apparatus is applied with another command signal representing the destination station where the articles 3 are to be unloaded or sorted. When the carrier structure 15 thus loaded with the articles 3 reaches at a predetermined sorting station, the carrier structure 15 is tilted whereby the articles slide down upon the chute 4 to be sorted.
The destination command apparatus, the control apparatus and the sorting chutes employed in conjunction with the operation of the automatic conveyor system of the present invention are well known in the art and do not constitute an essential part of the invention. Accordingly, further detailed description of these components will be omitted herein. It will be self-evident to those skilled in the art that the command of destination may be effected by using an electronic computer in place of the destination command apparatus or, alternatively, by employing photocell, or limit switch arrangements with destination identifying cards allotted to the articles or carrier structures. Of course, the sorting chutes at the sorting stations may be replaced by a roller conveyor or a belt conveyor.
Now, the invention will be described with reference to FIGS. 2-9 which show in some detail the carrier structure 15, the guide rail structure 14 and the switching mechanism for the automatic sorting conveyor system according to the invention.
Referring at first to FIGS. 2-5, each of the carrier structures 15 is essentially composed of plural sheets of slats 25 having end portions superposed to one another, supporting mechanisms 26, 27, 28 and 29 and the conveyor chain 31 for coupling the supporting mechanisms 26, 27, 28 and 29 in an endless manner. Although the carrier structure 15 is shown as composed of four sheets of slats 25 in the illustrated embodiment, it should be understood that an arbitrary number of slats 25 may be employed. Slats 25 are fixedly supported by the supporting mechanisms 26, 27, 28 and 29. In more detail, the first slat as viewed in the moving direction of the conveyor is supported by the supporting mechanism 26, while the second, third, and fourth slats are supported by the structures 27, 28 and 29, respectively. Each of these supporting mechanisms is mounted to the individual links 32 of the conveyor chain 31 in a manner shown in the drawings. The supporting structures 26, 27, 28 and 29 are constructed by supporting plates 41, 42, 43 and 44, yoke members 46, 47, 48 and 49, and fork members 51, 52, 53 and 54 which are pivotally connected to the yoke members 46, 47, 48 and 49 by pins 50 and secured to the respective links 32 of the conveyor chain 31 so that the supporting structures may be tilted. In case of the first supporting structure 26, it will be seen that the supporting plate 41 and the yoke member 46 are, respectively, divided into two corresponding members 56:57 and 58:59 so that a half portion of the supporting mechanism 26 may be utilized in the proceeding carrier structure 15. The second, third and fourth supporting plates 42, 43 and 44 have, respectively, slat mounts 62, 63 and 64 extending rearwardly as viewed in the direction of the conveyor movement at the both sides of the supporting plates and additionally have another slat mount 67, 68 and 69 extending forwardly beneath mounts 62, 63 and 64 in supporting contact therewith. In case of the first supporting structure 26, a similar slat mount 61 extends rearwardly from the plate member 57 secured to the yoke member 59, while a slat mount 66 extends forwardly from the plate member 56 secured to the yoke member 58. Secured to the mount plate 56 is a slat member 70 which extends in contact with and beneath the last slat of the proceeding carrier structure. It will be easily appreciated that the same holds true in case of the fourth slat 25.
In the third supporting structure 28 of the carrier structure 15, there are provided a pair of horizontally extending lateral arms 72 each of which has a supporting wheel 73 serving to support normally the carrier structure 15 at the free end portion thereof. These supporting wheels or rollers 73 are adapted to run along the guide rails 24 of the rail structure 14 and tilt the carrier structure 15 at a desired sorting position with the aid of the switching mechanism 80 described hereinafter. The fork members 51, 52, 53 and 54 of the supporting mechanisms 26, 27, 28 and 29 of the carrier structure 15 are connected through respective generally cruciform shape cross pin structures 33 to the associated links 32 of the conveyor chain 31 which are connected easily bendable for any lateral or horizontal movements. The cross pin 33 has four guide wheels or rollers 34 at the respective free ends which wheels are engageable with the guide rail 22 of the rail structure 14. The guide rail 22 is composed of rail members each having a configuration such as shown in FIG. 3 and supported by the supporting member 23. The guide rail is secured to the supporting frame 12. In this manner, the supporting mechanisms 26, 27, 28 and 29 are connected to one another in an endless fashion through the links 32 while the links are interconnected through the cross pins 33. The cross pin structures thus provide a universal joint type of pivotal connection between each of the adjacent links 32 whereby the supporting mechanisms can be moved along a horizontally or vertically curved track as defined by the rail structure. Further, since the four sheets of slats 25 are partially superposed to one another at their end portions, the tilting of the third supporting mechanism 28 as caused by the switching mechanism 80 at a desired sorting location will bring about a simultaneous tilting of all the four slats 25. For this reason it is sufficient to provide a single tilting mechanism comprising the arms 72 and the wheels 73 for one of the four supporting mechanisms 26, 27, 28 and 29, such as, for example, the third supporting structure 28 as is the case of the illustrated embodiment.
The switching mechanism for tilting the carrier structure thereby to sort the articles is provided for in the guide rail 24 at a desired sorting location in a position to be compatible with the sorting chutes 4 or sorting conveyors.
As is shown in FIGS. 6, 7, 8 and 9, the switching mechanism 80 comprises a guide channel member 82 of an inverted C cross section secured to a frame 89 supporting the guide rail 24, a swingable plate 83 pivotally supported by a pin 86 and swingable in a notch 85 formed in the track surface section of channel member 82 and an electro-magnetic solenoid apparatus 84 for actuating the swingable plate 83. Pin 86 is integrally formed in the swingable plate 83 at an end thereof and extends through the bearing portion of channel member 82. A lever 87 is secured to pin 83 at the extending end thereof. The lever 87 in turn has its other end connected to a link of the electro-magnetic solenoid apparatus 84. Upon actuation of the solenoid 84, the swingable plate 83 is caused to rotate around pin 86. When the solenoid apparatus of a selected switching mechanism is energized by an electric signal commanding the sorting of the articles 3 being carried, the swingable plate 83 is rotated upwardly and the notch 85 is thereby opened. When a desired carrier structure 15 has thereafter reached the position of the thus set switching mechanism 80, the corresponding one of wheels 73 mounted on the lateral arms 72 is guided through the notch 85 along the lower side surface of the swingable plate 83, as a result of which the supporting mechanism 28 and hence the whole carrier structure 15 are tilted. Thus, the articles 3 on the carrier structure 15 will slide down onto the chute 4 to be sorted. The carrier structure 15 thus unloaded is moved to a location where a resetting guide rail 91 is provided with the tilted position of the carrier structure being maintained as it is since the center of gravity of the structure is offset from the geometrical center thereof. The resetting guide rail 91 is provided at a location spaced from the sorting station by a suitable distance and serves to restore the tilted position of the carrier structure to the horizontal position (FIG. 9). The tilting angle of the carrier structure 15 is restricted to a predetermined value by means of a projection 74 (FIG. 4) disposed below arm 72 and adapted to strike against the fork member 53 of the supporting structure 28.
It will be evident to those skilled in the art that the electro-magnetic solenoid apparatus 84 of the switching apparatus may be replaced by a pneumatic or hydraulic mechanism. Similarly, a caterpillar drive may be employed in place of the screw drive drum 18 for driving the carrier structure 15.
OPERATION
The operation of the automatic sorting conveyor system according to the present invention having the construction as above described is as follows:
As hereinbefore described with reference to FIG. 1, the automatic sorting conveyor apparatus according to the present invention is installed in a desired closed loop track configuration having curved portions and different heights with the heights of the standby conveyor 2 at the loading station and the sorting chute 4 at the sorting stations being considered. In operation, a command signal representing the sorting station associated with the articles 3 resting on the standby conveyor 2 is supplied to a control apparatus (not shown) from the destination command apparatus 6. When the idle carrier structure 15 is moved near the standby conveyor 2 under the control of the controller not shown, the latter is operated to transfer the articles 3 to the carrier structure 15. When the carrier structure 15 thus loaded with the articles 3 approaches the designated sorting station, the control apparatus in which the corresponding sorting location is stored produces a changing-over command to the switching mechanism 80 upon which the solenoid 84 is energized to actuate the swingable plate 83. The switching of the guide rail thus involved will, in turn, cause the carrier structure 15 to be tilted at the predetermined location whereby the articles 3 will slide down onto the selected sorting chute 4. Thereafter, the carrier structure 15 thus having been unloaded is moved to the resetting location in the tilted state and restored to the horizontal position by the resetting guide rail 91 (FIG. 9).
In this manner, the automatic sorting conveyor system according to the present invention employed in combination with a conventional destination command apparatus and control apparatus will allow an automatic transportation of articles from the standby conveyor to a desired or predetermined sorting location designated by the destination command apparatus under the control of the control apparatus. Further, since in the automatic conveyor system according to the invention the conveyor means includes a plurality of carrier structures each having plural sheets of slats, for example, four sheets of slats, and connected to a conveyor chain in an endless fashion with the individual slats being partially superposed to one another, it is sufficient for the tilting operation of the carrier structure to provide a single supporting wheel assembly for each of the carrier structures. Besides, due to the feature that the links of the conveyor chain are interconnected bendably both in the horizontal and the vertical directions through cross pins having guide wheels at every arm, a loop-like conveyor track may be installed in any desired configuration or arrangement having various heights and laterally curved portions of relatively smaller radii so as to comply with the conditions imposed by the available space. By virtue of the feature that the sorting or unloading operation can be effected by the switching operation of the single supporting wheel assembly provided for each of the carrier structure, the efficiency of the sorting operation is highly improved. In accordance with the disclosed teaching of the invention, the tilting mechanism for the carrier structures, the switching mechanism for the guide rail as well as the conveyor driving apparatus can be realized in simplified and reliable constructions. The inventive conveyor system can be applied to a variety of sorting operations for various articles such as cardboard boxes, small sized articles, bag packages or the like. Because of the arrangement of the slats for each of the carrier structures being partially superposed to one another at the leading and trailing end portions, the slat arrangement may be considered dynamically as an integral structure and therefore the supporting of the articles as loaded as well as the transmission of the force for tilting the individual slats can be effected smoothly. It will be further noted that the individual slats can be slidably moved relative to one another at the curved path. This feature together with the above mentioned universal linkage assures that the inventive system can be satisfactorily employed even under the condition where considerable curved or horizontally bent or inclined paths are required.
Obviously, many modifications and variations of the invention are possible in light of the above teachings and it will be apparent to those skilled in the art that various changes in form and arrangement may be made to suit requirements without departing from the scope of this invention. Accordingly, it is intended that the equivalent arrangements be included unless the following claims by their wording expressly state otherwise. | In an automatic conveyor system, a plurality of independently operable carrier or transport structures are interconnected in closed loop configuration. Each carrier includes plural sheets of overlapping slats, each supported by a carriage which allows the slat to pivot for differential vertical flight level movement and tilting to either side for deposition of articles onto selected receiving stations. A plurality of carriages and slats form an independently operable unit to complement the article size structure with one of the slat supporting carriages in each unit having actuating elements in the form of a horizontal arm to each side with a roller which can be deflected for tilting. The single tilting of this arm causes all of the associated slats in that unit to tilt in unison as a result of their overlapping nature. | 1 |
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to the use of cementing plugs, balls, darts and other elements in the cementing of casing in oil and gas wells. More specifically, the invention relates to the remote controlled injection of cementing plugs into casing and/or drill pipe (hereinafter referred to as well pipe) which is hung in a well prior to the cementing operation and to displacement of cement from the well pipe after the cementing process has been completed. The remotely controlled cementing plug container of this invention is designed to release a bottom cementing plug as an interface between the drilling fluid and the cement by opening an air or hydraulic cylinder valve on a control panel remotely located from the cementing plug container and introducing a suitable fluid into the cementing plug container. The bottom cementing plug wipes the drilling fluid from the walls of the well pipe ahead of the cement slurry, reducing dilution. Upon completion of the cementing operation the cementing plug container is again remotely operated to drop a top cementing plug responsive to manipulation of a second air or hydraulic cylinder valve. The function of this plug is to follow the cement and prevent contamination or channeling of the cement with drilling fluid or other fluid used to displace the cement. The cementing plug container is operated to inject the bottom and top cementing plugs from the container housing into the well pipe at specified time intervals by operation of air or hydraulic cylinders responsive to manipulation of the remotely located air or hydraulic cylinder valves cooperating with the air or hydraulic cylinders. The apparatus of this invention is further characterized by a plug pass indicator which positively and both remotely and mechanically indicates when a plug or plugs have passed from the interior of the cementing plug container housing through the bore of the housing. The cementing plug container is specifically designed to quickly, efficiently and inexpensively inject one or more cementing plugs into a length of well pipe in an oil or gas well, both before and after the well pipe cementing operation and to verify that the plugs have been injected into the well pipe by using a control panel located some distance from the well, in order to minimize the time and cost of cementing the well pipe in the well and to maximize safety during the cementing operation.
Description of the Prior Art
Oil and gas well cementing operations have long been effected by the use of cementing plug containers which are typically designed to contain a single cementing plug for a first injection into the well pipe of the well prior to injecting cement and a second plug to displace the residual cement after the cementing operation. In most prior art operations a first plug is initially inserted in the cementing plug container by removing the dome, or top of the container, placing the plug in the housing and then replacing the dome. After the loading operation is completed, the plug is released by manually removing a retaining pin and is then forced downwardly from the cementing plug container and through the well pipe by pumping cement into the well pipe on top of the plug. The cement is forced through the well pipe and upwardly around the outside wall of the well pipe in the annulus between the well bore and the well pipe to secure the well pipe in position in the well. Subsequently, the dome is again removed and a second cementing plug is placed in the housing and forced through the well pipe to clear the well pipe of residual cement. In some operations it may not be necessary to use a bottom cementing plug and under these conditions, a single top cementing plug is used.
It will be recognized by those skilled in the art that this procedure of removing the dome, placing cementing plugs inside the cementing plug container and subsequently replacing the dome in the sequence described above is expensive, constitutes a safety hazard and is time-consuming. Accordingly, this operation adds time and expense to the cost of cementing and completing wells in oil and gas field operations and has been known to cause accidents. Furthermore, it is sometimes difficult to determine whether or not the plug or plugs have actually been forced from the cementing plug container into the well pipe, since no positive indicating mechanism is generally available to make this determination. Accordingly, it is frequently necessary to remove the dome from the housing in order to be sure that each cementing plug has been forced from the cementing plug container and into the well pipe.
An early patent dealing with the insertion of plugs in well pipe is U.S. Pat. No. 2,615,519, dated Oct. 28, 1952, to C. J. Carr. The Carr apparatus includes a vertically disposed tubular body which is provided with an internal bore for carrying at least one plug and at least one spring-loaded cam mechanism which selectively rotates into the housing bore to maintain the plug inside the bore and from the bore to drop the plug into the well pipe. U.S. Pat. No. 4,317,486, dated Mar. 2, 1982, to M. E. Harris, discloses a "Cementing Head Apparatus and Method of Operation". The cementing head is designed for injecting an omega-type cementing plug into a well pipe and carries the plug inside the hollow bore of the housing. A movable plunger is located above the plug and is actuated by an operating fluid such as hydraulic fluid. A control valve is situated below the plug and when the valve is closed, it prevents accidental downward movement of the plug into the well pipe. Following injection of the cement slurry into the well pipe, the valve is opened and the plunger is moved down to push the plug through the valve and beyond the cement inlet. A fluid such as water is then pumped through the cement inlet to force the plug down the well pipe behind the cement slurry. Another "Cementing Plug Apparatus" is disclosed in U.S. Pat. No. 3,322,197, dated May 30, 1967, to E. E. Baker, et, al. The cementing plug apparatus detailed in this patent includes a plug release device having a sleeve which extends outwardly from the side of a plug container. A plunger is mounted in the sleeve and in its extended position, the plunger prevents a plug in the plug container from passing into the well pipe. In its retracted position, the plunger does not extend into the interior of the plug container, thus the plug is free to pass downwardly into the well pipe. The plunger is locked in extended position by a pair of dogs which are mounted in the sleeve and are movable into and out of a recess in the plunger. A cylindrical body is mounted on the exterior of the sleeve and a counterbore in one end of the body forms a cylinder for receiving a retainer piston which is mounted coaxially on the sleeve. The retainer piston blocks displacement of the dogs out of the plunger recess when the piston is retracted into the cylinder. The piston is urged into the cylinder by a spring. U.S. Pat. No. 3,444,928, dated May 20, 1969, to C. A. Pitts, discloses a "Plug Injector Apparatus" which is characterized by a cylindrically-shaped plug container having a hollow bore for receiving a pair of plugs, which plugs are enclosed in sleeves that drop into place and seat in alignment with the well pipe as the retainer elements are moved to the plug injection position. The plugs are seated on vertically oriented, rotatable rings which are manually rotated into registration with the plug circumference to allow the plugs to drop through the rings and into the well pipe. Other patents which detail cementing heads for releasing plugs into well pipe are noted as follows: U.S. Pat. No. 3,076,509, dated Feb. 5, 1963, entitled "Cementing Head", to E. Burns, et, al; U.S. Pat. No. 3,971,436, dated July 27, 1976, entitled "Cementing Head", to William T. Lee; U.S. Pat. No. 3,616,850, dated Nov. 2, 1971, entitled "Cementing Plug Launching Mandrel", to Lyle B. Scott; U.S. Pat. No. 3,507,325, dated Apr. 21, 1970, entitled "Well Cementing Apparatus", to L. B. Scott; U.S. Pat. No. 3,216,500, dated Nov. 9, 1965, entitled "Plug Injector Apparatus", to T. W. Diehl; U.S. Pat. No. 3,926,253, dated Dec. 16, 1975, entitled "Well Conduit Cementing Adaptor Tool", to John A. Duke; and U.S. Pat. No. 3,863,716, dated Feb. 4, 1975, entitled "Cementing Plug Release Assist Apparatus", to Steven G. Steich. U.S. Pat. No. 4,427,065, dated Jan. 24, 1984, to James S. Watson, discloses a cementing plug container and method of use. This container is characterized by a shaped housing containing one or more plugs, a plug release mechanism for each plug and a plug indicating mechanism for indicating when the plugs move through the saver sub or indicator module after being dropped by the plug release mechanisms.
It is an object of this invention to provide a new, improved and safe cementing plug container and remote control system which is characterized by at least one plug release mechanism that may be remotely or manually operated and serves to release one or more cementing plugs located in the container into the well pipe in a safe, positive and efficient manner without the necessity of removing the dome from the container.
Another object of this invention is to provide a cementing plug container and cementing plug indicating and injection system which is characterized by a plug pass indicator positioned beneath the plug release mechanism and provided with an internal drop bar which is contacted by the cementing plug or plugs as the cementing plugs pass sequentially through the housing to positively indicate, both at the well location and on a remotely positioned control panel, when the cementing plugs have passed from the housing through the cementing plug container bore.
Yet another object of the invention is to provide a new and improved cementing plug container and remote control system which includes a plug release mechanism for supporting and releasing one or more cementing plugs in the container housing and a cementing plug passage indicator device, which plug release mechanism is characterized by a separate air or hydraulic cylinder and a cooperating remotely located release valve for releasing each cementing plug in a specified and controlled sequence. This release is effected by extension of the air or hydraulic cylinder piston with a working fluid responsive to manipulation of the valve. Passage of the plugs through the cementing plug container is indicated by the plug pass indicator device which is positioned beneath the plug release mechanism or mechanisms and is secured to an indicator module mounted in the cementing plug container housing.
Still another object of this invention is to provide a cementing plug container and remote control system for injecting cementing plugs into the well pipe of an oil or gas well, wherein the cementing plug container is fitted with multiple, fluid-operated plug release devices and a plug pass indicating device which are linked to a remote control panel. A pair of lights, light-emitting diodes, or like signal or indicating means are mounted on the control panel, which signal means are electrically wired to a proximity sensor located in the plug pass indicating device to verify sequential passage of the cementing plugs from the container housing into the well pipe.
A still further object of this invention is to provide a new and improved, remotely-operated, fluid-actuated plug release mechanism for supporting and releasing one or more cementing plugs in a cementing plug container apparatus and cementing casing in oil and gas wells. The plug release mechanism includes a support arm for supporting the plugs and the support arm is attached to a release shaft which is carried by a release cam for maintaining the release arm in supporting configuration. The release cam further cooperates with an air or hydraulic cylinder designed to facilitate downward rotation of the release arm by extension of the cylinder piston to allow the cementing plugs to drop in sequence from the upper interior portion of the container housing into the indicator module portion of the container housing for injection into the well pipe. A remote control panel having a valve for pneumatic or hydraulic control of each air or hydraulic cylinder, respectively, in the plug release mechanism is used to operate the plug release mechanism from a remote and safe location outside of the immediate proximity of the cementing plug container.
Another object of the invention is to provide a positive and efficient, mechanically-operated cementing plug container indicator mechanism for determining when one or more cementing plugs have moved from the upper segment of a remotely-operated cementing plug container housing through the indicator module of the housing. The indicator device includes an indicator plate wheel rotatably positioned on a cam clutch carried by a shaft which also supports a drop bar located in the indicator module and extends into the path of the plug or plugs. The shaft rotatably projects through the indicator module and a return spring is secured to a bracket plate which is attached to the shaft for returning the drop bar to an extended position in the indicator module after rotation of the indicator plate wheel responsive to contact between the drop bar and a falling cementing plug. In a most preferred embodiment a proximity sensor located in the indicator mechanism is provided in electrical contact with indicator lights mounted on a remote control panel to indicate when the cementing plugs have sequentially exited the cementing plug container.
Yet another object of this invention is to provide a method for cementing casing in a well by remote control using a cementing plug container, which method includes the steps of providing the cementing plug container with at least one plug release mechanism and a plug indicating mechanism; providing a remote control panel fitted with control means linked in fluid cooperation to the plug release mechanism and in electrical association with the plug indicating mechanism; and operating the control means to manipulate the plug release mechanism and deposit cementing plugs in the well pipe.
Yet another object of this invention is to provide a method for depositing multiple plugs in the well pipe of a well by remote control using a cementing plug container having a removable dome, which method includes the steps of providing the cementing plug container with multiple fluid-operated plug release mechanisms oriented in stacked relationship in the cementing plug housing; locating multiple valves on a remote control panel distanced from the cementing plug container; linking the valves and plug release mechanisms with fluid conduits, respectively; providing an actuator in fluid cooperation with the cementing plug container and actuator control means located on the remote control panel and provided in fluid cooperation with the actuator for delivery of the fluid to the cementing plug container; and providing a plug pass indicator mechanism in the cementing plug container beneath the plug release mechanisms and establishing an electrical connection between the plug pass indicator mechanism and lights provided on the remote control panel to indicate when the plugs have passed from the cementing plug container into the well pipe responsive to operation of the valves and the actuator control means.
SUMMARY OF THE INVENTION
These and other objects of the invention are provided in a new and improved cementing plug container and method for injecting cementing plugs into the well pipe of an oil or gas well using a remote control apparatus. First operational elements in the cementing plug container include a plug release mechanism for each cementing plug, which plug release mechanisms are designed to support and selectively release multiple cementing plugs in the housing. Each cementing plug release mechanism further includes a plug release arm for supporting a cementing plug and the cementing plugs are normally inserted in stacked relationship in an upper segment of the housing. A shaft carrying the plug release arm at one end extends through the housing and is attached to a release cam at the opposite end. A cam lock mechanism is provided in cooperation with an air or hydraulic cylinder and the release cam, whereby energizing of the air or hydraulic cylinder by activation of an air or hydraulic cylinder valve mounted on a control panel effects linear movement of the cam lock mechanism and rotation of the release cam and the support arm to permit each cementing plug to drop in sequence from an initial position in the upper part of the container housing into the housing bore for injection into the well pipe. A plug pass indicator is characterized by a rotating indicator plate wheel positioned outside the cementing plug container housing beneath the plug release mechanism or mechanisms. The indicator plate wheel is carried by a cam clutch mounted on a rotatable shaft which extends through the housing and carries a drop arm which projects into the indicator module bore. The wheel is rotated one-quarter turn responsive to movement of each cementing plug through the housing and indicator module bore as each cementing plug contacts the drop bar and rotates the shaft. A remote control panel is provided with air or hydraulic cylinder valves, an actuator valve, air or hydraulic cylinder supply lines, fittings and a source of electricity such as a battery, as well as indicator lights for pneumatic or hydraulic control of the plug release mechanism at a distance. A proximity sensor located in the plug pass indicator device is electrically connected to indicator lights located in the control panel to remotely indicate when the cementing plugs have exited the cementing plug container.
A method for depositing plugs into a well pipe by remote control using a cementing plug container having a removable dome, which method includes the steps of providing the cementing plug container with at least one plug release mechanism and a plug indicating mechanism; providing a remote control panel with appropriate controls for intorducing fluid into the cementing plug container and operating the plug release mechanism at a distance; and further providing indicating or signal indicia mounted on the remote control panel and associated with the plug indicating mechanism for determining when a cementing plug or plugs exit the cementing plug container and are injected into the well pipe responsive to manipulation of the controls.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood by reference to the accompanying drawings wherein:
FIG. 1 is a front elevation of a first preferred embodiment of the cementing plug container of this invention, more particularly illustrating external elements of the plug release mechanisms and the plug pass indicator mechanism;
FIG. 2 is a right side elevation of the cementing plug container illustrated in FIG. 1;
FIG. 3 is a sectional view taken along line 3--3 of the cementing plug container illustrated in FIG. 2;
FIG. 4 is a front elevation, partially in section, of one of the plug release mechanisms illustrated in FIG. 1;
FIG. 5 is a top elevation of the plug release mechanism illustrated in FIG. 4;
FIG. 6 is a right end elevation of the plug release mechanism illustrated in FIGS. 4 and 5;
FIG. 7 is a perspective view, partially in section, of the cementing plug container illustrated in FIG. 1, with a pair of cementing plugs loaded in the cementing plug container;
FIG. 8 is a perspective view of the indicator module element of the cementing plug container illustrated in FIG. 7, more particularly illustrating the plug pass indicator;
FIG. 9 is a front elevation of the indicator plate wheel element of the plug pass indicator illustrated in FIG. 8;
FIG. 10 is an exploded view of the plug pass indicator illustrated in FIG. 8;
FIG. 11 is a side sectional view of the plug pass indicator illustrated in FIG. 8, with the plug pass indicator positioned in functional orientation in the indicator module.
FIG. 12 is an exploded view of the plug pass indicator illustrated in FIG. 8, more particularly illustrating the relative positions of the drop bar, collar bracket and indicator plate wheel before a cementing plug contacts the drop bar;
FIG. 13 is an exploded progress view of the plug pass indicator illustrated in FIG. 12, more particularly illustrating relative movement of the drop bar, collar bracket and indicator plate wheel when a cementing plug contacts the drop bar;
FIG. 14 is an exploded progress view of the plug pass indicator illustrated in FIGS. 12 and 13, illustrating further relative movement of the drop bar, collar bracket and indicator plate wheel as the cementing plug passes completely through the indicator module bore;
FIG. 15 is a front elevation of an alternative preferred embodiment of the cementing plug container of this invention;
FIG. 16 is a front sectional view of the cementing plug container illustrated in FIG. 15;
FIG. 17 is a front elevation of yet another preferred embodiment of the cementing plug container of this invention;
FIG. 18 is a front sectional view of the cementing plug container illustrated in FIG. 17; and
FIG. 19 is a front elevation of the cementing plug container illustrated in FIG. 1 provided in electrical and pneumatic or hydraulic connection to a remote control panel.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1-3 of the drawings, in a preferred embodiment the cementing plug container of this invention is generally illustrated by reference numeral 1 and includes a dome 20, an upper housing 2 and lower housing 11 and an indicator module 24 extending from the lower housing 11. A top plug chamber 3 and a bottom plug chamber 12 accommodate a pair of cementing plugs, identified as a top plug 33 and bottom plug 35 in FIG. 3, in the hollow interior of the cementing plug container 1 and the dome 20 is provided with a pair of dome flanges 21, fitted with flange apertures 22, for lifting purposes. The upper housing 2 and lower housing 11 are also fitted with inlet castings 29 for introducing cement into the top plug chamber 3 and bottom plug chamber 12, if desired, and a manifold assembly 28, fitted with an indicator module inlet 31, is provided for introducing fluid into the interior of the indicator module 24.
A bottom plug release is generally illustrated by reference numeral 13 and the external component parts of the bottom plug release 13 are mounted on a shaft housing 19 in the lower housing 11, as illustrated in FIG. 2. Among the exterior component parts of the bottom plug release 13 is the bottom cylinder 14, which is characterized by a cylinder piston housing 51 having a front base 46 and a rear base 47, as illustrated. The cylinder piston rod 6 of the bottom cylinder 14 cooperates with a bottom cam lock 16 to slide the bottom cam lock 16 forward with respect to a cam lock release pin 42 and release the bottom plug release cam 15 to drop the bottom plug 35 to the mouth 30 of the indicator module bore 26, as hereinafter described. A top plug release is generally illustrated by reference numeral 4 and is positioned above the bottom plug release 13 on a shaft housing 19, located in the upper housing 2. A top cylinder 5, also having a front base 46 and a rear base 47 connected by a cylinder piston housing 51, is provided with a cylinder piston rod 6 in cooperation with a top cam lock 8 and a cooperating top plug release cam 7. Accordingly, it will be appreciated that energizing of the top cylinder 5 releases the top cam lock 8 from the top plug release cam 7 and allows the top plug 33 to drop from the top plug chamber 3 to the mouth 30 of the indicator module bore 26 after release of the bottom plug 35, as hereinafter described.
As further illustrated in FIGS. 1 and 2 of the drawings, a plug pass indicator, generally illustrated by reference numeral 27, is positioned beneath the bottom plug release 13. In a preferred embodiment of the invention the plug pass indicator 27 is mounted to the indicator module 24 and is designed to indicate when the top plug 33 and bottom plug 35, located in the interior of the plug chamber bore 23 of the upper housing 2 and lower housing 11, respectively, are released from the top plug release 4 and the bottom plug release 13. The well pipe connector 25 which extends from the indicator module 24 is designed to be threaded and attached to the well pipe (not illustrated) in an existing oil or gas well.
Referring again to FIG. 3 of the drawings the cementing plug container 1 is characterized by a hollow interior which is shaped to define a plug chamber bore 23 in the interior of the top plug chamber 3 and bottom plug chamber 12, respectively. In a preferred embodiment of the invention the dome 20 is threadibly attached to the upper housing 2 by means of housing threads 38 and rests on an upper housing shoulder 10 of the upper housing 2. Similarly, the upper housing 2 is attached to the lower housing 11 and rests on a lower housing shoulder 18 and the lower housing 11 is connected to the indicator module 24, respectively, by means of additional housing threads 38. Should entry of fluids into the plug chamber bore 23 be desired, the inlet castings 29 can be drilled and tapped and inlet lines added to the manifold assembly 28, as deemed necessary.
Referring again to FIGS. 1-3, it will be appreciated that the top plug release shaft 9 of the top plug release 4 and the bottom plug release shaft 17 of the bottom plug release 13 each extend through a separate shaft housing 19, respectively, and carry a plug release arm 39, disposed in the top plug chamber 3 and bottom plug chamber 12, respectively. Accordingly, as hereinafter more particularly described, when the top cylinder 5 and bottom cylinder 14 are energized in the proper sequence, each of the respective companion plug release arms 39 are caused to rotate downwardly and sequentially release the top plug 33 and the bottom plug 35, respectively, resting on the plug release arms 39, at the appropriate time. The top plug 33 and bottom plug 35 then drop to the mouth 30 of the indicator module bore 26, which is smaller in diameter than the plug chamber bore 23 and the projecting top plug ribs 34 and bottom plug ribs 36, respectively. Accordingly, both the top plug 33 and bottom plug 35 remain in contact with the top portion or mouth 30 of the indicator module bore 26 until they are forced through the indicator module bore 26 and into the well pipe (not illustrated) by cement or other fluid pressure, as hereinafter described.
As illustrated in FIGS. 1-3, 4, 5 and 6 of the drawings, FIGS. 4-6 of which illustrate the top plug release 4 in detail, it will be appreciated that the top plug release 4 and bottom plug release 13 are identical in mechanical configuration and function. Referring specifically to FIGS. 5 and 6, as heretofore described, the top plug release shaft 9, which carries the top plug release cam 7, rotatably extends through a shaft housing 19, with the plug release arm 39 projecting through the upper housing 2 and into the top plug chamber 3. Accordingly, the top cylinder 5 and its companion cylinder piston rod 6, provided with piston rod threads 45; the piston seal 50, as well as the top plug release cam 7; the top cam lock 8 and cooperating cam lock finger 41; and the cam lock base 44, to which the cylinder piston rod 6 is threadably secured, are all positioned outside of the upper housing 2. Furthermore, the O-ring shoulders 55, which contain a pair of spaced O-rings 56 and the end of the top plug release shaft 9 located opposite the top plug release cam 7, extend inside the shaft housing 19, with a set screw 54 threadably inserted in the wall of the shaft housing 19 and engaging a set screw release groove 53 provided in the release shaft collar 52, to secure the O-ring shoulders 55 and the O-rings 56 in rotatable relationship inside the shaft housing 19. Accordingly, it will be appreicated that since the top plug release shaft 9 is secured to the top plug release cam 7 at one end and since the O-ring shoulders 55 are rotatably located inside the shaft housing 19, the companion plug release arm 39 is free to rotate with the top plug release shaft 9 upon rotation of the plug release cam 7. Referring to FIG. 4, it will be further appreciated that the top cylinder 5 can be energized by injecting air or hydraulic fluid, as appropriate, into the cylinder piston housing 51 through a rear base aperture 49 provided in the rear base 47. This fluid introduction expels air from a front base aperture 48 in the front base 46 and compresses a spring (not illustrated) located in the cylinder piston housing 51, to extend the cylinder piston rod 6 and slidably displace the top cam lock 8 on the cam lock release pin 42, due to the width of the cam lock aperture 43 provided in the top cam lock 8. This forward motion of the top cam lock 8 with respect to the cam lock release pin 42 disengages the cam lock finger 41 from a companion cam slot 40, provided in the top plug release cam 7. Further extension of the cylinder piston rod 6 exerts pressure on the cam lock release pin 42, which is attached to the top plug release cam 7 and causes the top plug release cam 7 and the plug release arm 39 to rotate in the counter-clockwise direction. Rotation of the plug release arm 39 allows the top plug 33 to fall from its position inside the top plug chamber 3 to the mouth 30 of the indicator module bore 26. It will be appreciated that prior to activation of the top plug release 4, the bottom plug 35 would have been previously released from its position on the bottom plug release arm 39 responsive to activation of the bottom cylinder 14 in the manner described above with respect to the top cylinder 5. The cylinder piston rod 6 is retracted by reducing the fluid pressure to the rear base aperture 49 and allowing the spring-loaded top cylinder 5 to retract into the configuration illustrated in FIGS. 4 and 5, as hereinafter described.
Referring now to FIGS. 1, 2 and 7-9 of the drawings the plug pass indicator is generally illustrated by reference numeral 27 and is mounted in the indicator module 24 adjacent to the enlargement 24a. External elements of the plug pass indicator 27 include a flat mount plate 85, which is bolted to a mount plate base 86, mounted on the indicator module 24 and a proximity sensor 81a, attached to the mount plate 85 and provided with a sensor head 89, as illustrated in FIG. 2. An indicator plate 57 is attached to the mount plate 85 by means of two plate mount bolts 75, which register with indicator plate apertures 69 located in the indicator plate 57 and with cooperating threaded apertures (not illustrated) provided in the mount plate 85. As illustrated in FIGS. 9 and 10, an indicator plate wheel 58 is visible through a window provided in the indicator plate 57 and the indicator plate wheel 58 is divided into quadrants which are color-coded. As illustrated in FIG. 9, the quadrants are provided with different colors as follows: A black panel 59 is provided in one quadrant a red panel 60 in the adjacent quadrant, a white panel 61 is provided in the next successive quadrant and a yellow panel 62 marks the fourth, and last quadrant.
Referring now to FIGS. 7-11, in a preferred embodiment of the invention the indicator plate wheel 58 is attached to the indicator module 24 by means of a shaft 63, a portion of which shaft 63 extends inside the indicator module bore 26 and is rotatably sealed across the curved wall of the enlargement 24a in the indicator module 24, by means of a pair of shaft O-rings 70. The drop arm 74 extends from an arm base 72, which is attached to an enlarged shaft collar 73, provided on the shaft 63. The drop arm bracket 71, which includes the shaft collar 73, the arm base 72 and the drop arm 74, is located inside the indicator module bore 26 in the enlarged bore cavity 90 shaped by the enlargement 24a. As illustrated in FIG. 10, a square collar enlargement 84 is positioned on that portion of the shaft 63 which extends outside the indicator module 24 and the inner race 67 of a cam clutch 65 is tightly secured to the projecting end of the shaft 63 against a clutch collar 64, extending from the collar enlargement 84. The outer race 66 of the cam clutch 65 is secured to the indicator plate wheel 58. A ball track 68 is positioned between the inner race 67 and the outer race 66 and carries several ball bearings and cams (not illustrated), which cams allow the indicator plate wheel 58 and the outer race 66 to rotate in the counter-clockwise direction when viewing the indicator plate wheel 58 from the front. However, while the shaft 63, the clutch collar 64 and the inner race 67 are free to rotate in the clockwise direction, the indicator plate wheel 58 and the outer race 66 are maintained in the counter-clockwise rotated position, as hereinafter described. In a preferred embodiment of the invention the cam clutch 65 used in the plug pass indicator 27 is a model KK-17 cam clutch sold under the "Morse" trademark.
As illustrated in FIGS. 10 and 11 of the drawings, the collar enlargement 84 is disposed on the shaft 63 between the collar bracket legs 77 of a collar bracket 76 and the collar bracket legs 77 are secured in this position by means of a collar bracket bolt 79, which is threaded in one of the collar bracket legs 77. A collar bracket base 78 supports the collar bracket legs 77 and one end of a return spring 82 is secured to the projecting end of the collar bracket neck 80 by means of a neck bolt 83, which collar bracket neck 80 extends the collar bracket base 78. As illustrated in FIG. 8, the opposite end of the return spring 82 is seucred to the mount plate 85 by means of a mount plate bolt 87. A sensor plate 81 is secured to the collar bracket neck 80 and is positioned directly adjacent to, but spaced from the sensor head 89 of the proximity sensor 81a, which is attached to a sensor bracket 88, extending from the mount plate 85.
Referring now to FIGS. 15 and 16 of the drawings, in an alternative preferred embodiment of the invention the cementing plug container 1 consists of a dome 20, threadably secured to an upper housing 2 by means of housing threads 38 and an indicator module 24, also connected by means of housing threads 38 directly to the upper housing 2. In this embodiment of the invention the lower housing 11, illustrated in FIGS. 1 and 2, is eliminated under circumstances where a single top plug 33 is provided in the cementing plug container 1 and is used to clean cement residue from the well pipe. A plug pass indicator 27 is provided in the indicator module 24, as described above, with the drop arm bracket 71 located in the bore cavity 90 as illustrated, in order to indicate the passage of the top plug 33 through the indicator module bore 26, as heretofore described.
Referring to FIGS. 17 and 18, in a still further preferred embodiment of the invention the dome 20 can be directly and threadably attached to the indicator module 24 by means of housing threads 38, with a plug pass indicator 27 provided in the indicator module 24, as heretofore described. In this embodiment of the invention, no cementing plugs are inserted inside the dome 20 and the cementing plug container 1 is simply used to inject fluids into the well, as desired. Furthermore, the plug pass indicator 27 is provided in the indicator module 24 simply to demonstrate the versatility of interchanging parts in the cementing plug container 1.
Referring now to FIG. 19 of the drawings in another preferred embodiment of the invention the cementing plug container 1 is operated by controls located on a control panel 91, which can be removed from the immediate vicinity of the cementing plug container 1 and the well to reduce the danger of operating the cementing plug container 1. In a most preferred embodiment the control panel 91 is provided with an outline 92 of the cementing plug container 1 and an actuator valve 93 serves to selectively admit compressed air or hydraulic fluid through the actuator 101 and indicator module inlet 31, into the indicator module 24 of the cementing plug container 1, as hereinafter described. It will be appreciated that the valving and operation of the cementing plug container 1 can be achieved by using many fluids known to those skilled in the art, including gases, such as compressed air and nitrogen, and liquids, such as oil and hydraulic fluid, in non-exclusive particular. Accordingly, a fluid such as compressed air is supplied to the actuator valve 93 from a supply manifold 94, through an actuator valve intake line 94a. The fluid flows into the manifold 94 through a manifold intake line 95 and a pressure regulator 96, from a fluid intake line 97 and is controlled by a fluid inlet control knob 97a by monitoring a fluid pressure gauge 98. Various fluids such as compressed air and hydraulic fluid can be injected into the system through an air supply line 104 and a hydraulic fluid supply line 105, depending upon the selected design of the pressure regulator 96, actuator 101, actuator valve 93, top cylinder valve 99, top cylinder 5, bottom cylinder valve 100 and bottom cylinder 14. Accordingly, it will be recognized that the pressure regulator 96 can be characterized as either a hydraulic or an air-operated regulator to accommodate the chosen working fluid in the system, according to the knowledge of those skilled in the art. The top cylinder valve 99 is provided on the control panel 91 in pneumatic or hydraulic cooperation with the top cylinder 5 by means of a top valve discharge line 106, which extends from the top cylinder valve 99 to connect in the rear base aperture 49 of the rear base 47 located in the top cylinder 5 and the appropriate working fluid is supplied to the top cylinder 5 on demand from the top cylinder valve 99. Similarly, a bottom cylinder valve 100 is provided on the control panel 91 at the appropriate point on the outline 92 and is in pneumatic or hydraulic cooperation with the bottom cylinder 14 in the cementing plug container 1 by means of a bottom valve discharge line 107, which connects to the rear base aperture 49 of the rear base 47 in the bottom cylinder 14. The selected working fluid is supplied to both the top cylinder valve 99 and the bottom cylinder valve 100 through cylinder valve intake lines 108, which communicate with the manifold 94. In yet another most preferred embodiment of the invention a battery 109 is provided in the control panel 91 and battery wiring 110 is extended from one terminal of the battery 109 to a bottom plug light 112, which is wired in series with the battery 109 and with a top plug light 111, by means of plug light wiring 113. The plug light wiring 113 is also connected to the proximity sensor 81a, as illustrated in FIG. 2, in order to illuminate the top plug light 111 and bottom plug light 112 in sequence, upon operation of the plug pass indicator 27. In a most preferred embodiment of the invention a circuit board 114 is mounted on the control panel 91 and is fitted with an electronic circuit that is electrically connected to the plug light wiring 113. The circuit board 114 is designed to facilitate operation of the bottom plug light 112 and top plug light 111, as well as any other plug lights which may be provided in the control panel 91, in sequence from bottom to top, as the proximity sensor 81a operates responsive to passage of the bottom plug 35, top plug 33 and other plugs through the indicator module bore 26, as hereinafter described.
In operation, and referring again to FIGS. 1-3 and 19 of the drawings, under circumstances where the cementing plug container 1 is characterized by a dome 20, an upper housing 2, a lower housing 11 and an indicator module 24, the cementing plug container 1 can be used to inject a top plug 33 and a bottom plug 35 into a well pipe as follows. The well pipe connector 25 is initially threaded and prepared for connection to an existing oil or gas well according to procedures known to those skilled in the art. After the cementing plug container 1 has been connected to the well head, the plug light wiring 113 and battery wiring 110 are connected to the top plug light 111 and bottom plug light 112 and wired to the proximity sensor 81a and the battery 109, as heretofore described. The top valve discharge line 106 is then extended from the top cylinder valve 99 to a connection in the rear base aperture 49 of the top cylinder 5 and the bottom valve discharge line 107 is extended from the bottom cylinder valve 100 to a connection in the rear base aperture 49 of the bottom cylinder 14, to pneumatically or hydraulically connect the cementing plug container 1 to the control panel 91, depending upon the design choice of the actuator 101, actuator valve 93, top cylinder valve 99, top cylinder 5, bottom cylinder valve 100 and bottom cylinder 14. The actuator fluid lines 102 are then installed between the actuator valve 93 and the actuator 101. A compressor or hydraulic fluid pump (not illustrated) is subsequently activated to supply the chosen working fluid to the pressure regulator 96 and supply manifold 94 through the fluid inlet line 97. The dome 20 is subsequently removed from the upper housing 2, the upper plug release arm 39 is rotated downwardly by manipulation of the top cylinder valve 99 from the "RETAIN" position to the "DROP" position in order to energize the top cylinder 5 and the bottom plug 35 is placed on the lower plug release arm 39 in the bottom plug chamber 12 of the lower housing 11, as illustrated in FIG. 3. Subsequently, the upper plug release arm 39 is rotated upwardly by returning the top cylinder valve 99 to the "RETAIN" position and a top plug 33 is placed in position on the upper plug release arm 39. The dome 20 is then threadably replaced on the upper housing 2 and is secured tightly on the housing threads 38 against the upper housing shoulder 10 and the cementing plug container 1 is ready for operation. Alternatively, the cementing plug container 1 can be pre-loaded with the top plug 33 and a bottom plug 35, as desired. When it is desired to begin pumping cement through the cementing plug container 1 and into the well pipe, the bottom plug release 13 is activated by manipulating the bottom cylinder valve 100 from the "RETAIN" to the "DROP" position and compressed air or hydraulic fluid is charged through the bottom valve discharge line 107 to energize the bottom cylinder 14 and extend the companion cylinder piston rod 6. This action also extends the bottom cam lock 16 and cam lock finger 41, which are attached to the cylinder piston rod 6, as illustrated in FIGS. 4-6, to release the cam lock finger 41 from the cam slot 40 of the bottom plug release cam 15, as heretofore described. The bottom plug release cam 15 and companion plug release arm 39 then rotate in the counter-clockwise direction responsive to further extension of the cylinder piston rod 6, causing the bottom plug 35 to drop to the mouth 30 of the indicator module bore 26, where the bottom plug ribs 36 of the bottom plug 35 contact the mouth 30 of the indicator module bore 26 and prevent the bottom plug 35 from moving further downwardly. The actuator valve 93 is then manipulated from the "CLOSED" to the "OPEN" position to allow working fluid to flow through one of the actuator fluid lines 102 and open the actuator 101. Cement or any alternative fluid is then pumped through the actuator 101 and indicator module inlet 31 and into the indicator module 24 through the indicator module inlet 31 of the manifold assembly 28 to secure the well pipe in the well bore and the pressure of the appropriate fluid forces the bottom plug 35 through the indicator module bore 26 and the well pipe to precede the cement into the well pipe. When it is desired to clear the well pipe of residual cement, the top plug release 4 is operated by manipulating the top cylinder valve 99 from the "RETAIN" to the "DROP" configuration, in order to energize the top cylinder 5, extend the companion cylinder piston rod 6 and release the top plug release cam 7 from the cooperating cam lock finger 41, as heretofore described with regard to the bottom plug release 13. Further extension of the cylinder piston rod 6 causes the top plug release cam 7 to rotate in the counter-clockwise direction and moves the upper plug release arm 39 downwardly, causing the top plug 33 to fall to the mouth 30 of the indicator module bore 26. A displacing fluid such as drilling mud, in non-exclusive particular, is then introduced into the actuator 101 and indicator module inlet 31 to force the top plug 33 through the indicator module bore 26 and into the well pipe. As illustrated in FIGS. 1 and 8 of the drawings, in a most preferred embodiment of the invention the indicator module inlet 31 is attached to the indicator module 31 at a tangent instead of at the diameter of the indicator module 31 cross-section. This mechanical arrangement assures the production of a vortex or tornado fluid flow inside the indicator module bore 26 and the resulting vacuum, coupled with the fluid pressure exerted on the plug from above, forces the bottom plug 35 and top plug 33 through the indicator module bore 26.
Referring again to FIGS. 1-14 it will be appreciated that when both the top plug 33 and bottom plug 35 are sequentially forced through the indicator module bore 26, the top plug ribs 34 of the top plug 33 and the bottom plug ribs 36 of the bottom plug 35 contact the drop arm 74 of the plug pass indicator 27 and force the drop arm 74 downwardly against the tension in the return spring 82. As illustrated in FIGS. 11 and 12, when the cementing plug container 1 is loaded with the top plug 33 and the bottom plug 35, the drop arm 74 is in the position indicated in FIGS. 11 and 12. As illustrated in FIGURE 13, when the bottom plug 35 is dropped and enters the indicator module bore 26 and contacts the drop arm 74, the drop arm 74 is forced downwardly in the indicator module bore 26, as indicated by the arrow. This movement of the drop arm 74 causes the shaft 63, indicator plate wheel 58 and the collar bracket 76 to rotate, as illustrated. As the bottom plug 35 continues to move downwardly through the indicator module bore 26 responsive to the fluid pressure differential, the drop arm 74 continues to pivot downwardly and finally pivots into the bore cavity 90, as illustrated in FIG. 14. When the drop arm 74 is in this extreme downward position, the indicator plate wheel 58 is rotated one-fourth of a complete revolution and the red panel 60 is located in the relative position which the white panel 61 occupied when the drop arm 74 was in the position illustrated in FIG. 12. The collar bracket 76 thus extends outwardly of the indicator module 24 against the bias of the return spring 82 and when the bottom plug 35 has moved through the indicator module bore 26 and past the bore cavity 90, the return spring 82 causes the drop arm 74 and collar bracket 76 to return to the original position illustrated in FIGS. 11 and 12. However, as heretofore described, while the shaft 63, clutch collar 64 and the inner race 67 of the cam clutch 65 also return to the respective original positions illustrated in FIGS. 11 and 12 responsive to the bias in the return spring 82, the outer race 66 and indicator plate wheel 58 remain in the one-quarter turn configuration. The plug pass indicator 27 is then in the "READY" position to indicate passage of the top plug 33 through the indicator module bore 26.
Referring again to FIGS. 2, 11 and 12 of the drawings the sensor head 89 of the proximity sensor 81a is separated from the pivoting sensor plate 81 and as long as this relative position of the sensor plate 81 and sensor head 89 exists, the electromagnetic field developed by the proximity sensor 81a is unbroken and neither the top plug light 111 or the bottom plug light 112 located on the control panel 91 are illuminated. However, when the bottom plug 35 forces the drop arm 74 downwardly and the collar bracket 76 outwardly, the sensor plate 81 swings outwardly with the collar bracket 76 and away from the sensor head 89. When the sensor plate 81 moves away from the sensor head 89 in this manner, the electromagnetic field is broken and the proximity sensor 81a sends a signal to the control panel 91 through the plug light wiring 113, which signal illuminates the bottom plug light 112, thereby notifying the operator that the bottom plug 35 has passed through the indicator module bore 26 and into the well. The sequence is orchestrated by the circuit board 114 and is repeated to illuminate the top plug light 111 when the bottom plug 35 is ejected through the indicator module 24.
Referring again to FIGS. 1 and 4-6 of the drawings, it is understood that the top plug release 4 and the bottom plug release 13 can be manually manipulated if desired, by grasping the top cam lock 8 and bottom cam lock 16, unthreading the top cam lock 8 and bottom cam lock 16 from the respective cylinder piston rods 6 and then forcing the top cam lock 8 and bottom cam lock 16 forwardly against the cam lock release pins 42, respectively, to sequentially release the bottom plug 35 and top plug 33. It is further understood that while the upper housing 2, lower housing 11, dome 20, indicator module 24 and well pipe connector 25 can be fabricated of substantially any material, aluminum is a preferred material of construction, in order to reduce weight and enhance the portability of the cementing plug container 1. Steel is another preferred material of construction for certain applications requiring very high operating pressure.
It will be appreciated that the cementing plug container of this invention is characterized by utility, convenience and efficiency, since it can be manually or remotely operated, using one or more cementing plugs of various design. The cementing plug container is designed to use interchangeable housing parts and an appropriate control system, such as the system disclosed herein, utilizing a variety of working fluids, including compressed air, nitrogen, hydraulic fluid and oil, in non-exclusive particular, as the source of power for operating the plug release mechanism or mechanisms. While two cementing plugs are illustrated in the drawings, it will be appreciated that additional plugs of any desired design supported by additional plug release mechanisms can be implemented in a corresponding cementing plug container, as desired.
As heretofore described, in a most preferred embodiment of the invention and referring again to FIG. 19 of the drawings, the control system for the top plug release 4 and the bottom plug release 13, as well as the top plug light 111 and bottom plug light 112, which indicate the passage of the top plug 33 and bottom plug 35 through the indicator module bore 26, are securely mounted on the control panel 91. The control panel 91 can be remotely located from the cementing plug container 1 for ease and safety in monitoring and operating the cementing plug container 1, as described herein. It will be appreciated that by the term "remotely located," it is intended that the control panel 91 can be removed any desired distance from the cementing plug container 1 and the well location, which distance is limited only by the practical length of the working fluid conduit and electrical lines connecting the cementing plug container 1 and the control panel 91. Furthermore, while fluid operation of the cementing plug container 1 is preferred, other means for remotely operating the plug release mechanisms, such as radio control and electric motors, can also be used, according to the knowledge of those skilled in the art.
While the preferred embodiments of the invention have been described above, it will be recognized and understood that various modifications may be made therein and the appended claims are intended to cover all such modifications which may fall within the spirit and scope of the invention. | A cementing plug container and remote control system for enclosing and injecting cementing plugs into the casing and/or drill pipe of an oil or gas well, which includes a shaped housing containing one or more plugs and a plug release mechanism such as an air or hydraulic cylinder for each plug, by operation of appropriate valves located on a control panel remotely located from the cementing plug container. Passage of the plug or plugs from the upper segment of the housing and through the housing assembly bore is registered by a plug pass indicator.
A method for injecting cementing plugs into casing and/or drill pipe in an oil or gas well by remote control using a cementing plug container having a removable dome, at least one remotely controlled plug release mechanism, and a plug pass indicator mechanism. | 4 |
BRIEF DESCRIPTION OF THE INVENTION
This invention relates in general to an optical pellicle and, more particularly, to a pellicle with anti-reflective coatings.
BACKGROUND OF THE INVENTION
Optical pellicles are generally used to seal a photomask or reticle, isolating the photomask surface from particulate contamination and eliminating dust or other particles from the focal plane of the photomask pattern during the fabrication of integrated circuits. The optical characteristics of the pellicle are important since the ultraviolet light, electromagnetic radiation and the like used during the photolithography process passes through the pellicle and photomask before reaching the wafer surface. Transmission losses due to absorption or reflection reduce the amount of usable light reaching the wafer surface to lengthen the exposure time required, reducing efficiency and increasing production costs. Many photolithography processes employ Mercury arc lamps which produce a maximum output at about 365 nm and 436 nm. The wavelengths correspond to the I and G lines, respectively, of a Mercury atomic spectrum. The H-line, corresponding to a wavelength of about 405 nm, is no longer used for many applications. Typically, photolithography equipment use either I-line or G-line wavelengths in the range of 365±4 nm and 436±6 nm. A pellicle in which the peak transmission corresponds to the maximum output of the I and G lines of a Mercury arc lamp is desirable because it can be used with either I-line or G-line photolithography equipment.
Preferably, the pellicle transmittance of the I-line and G-line wavelengths should be greater than 98 percent of the incident or illuminating light. A pellicle having a thickness of about 0.72 μm is disclosed by the Ron Hershell article entitled "Pellicle Protection of IC Masks," SPIE Vol. 275 Semiconductor Microlithography VI (1981). The article states that the disclosed pellicle has a transmission peak which corresponds to a wavelength of 436 nm and claims that the pellicle provides better than 99 percent transmission at wavelengths of 436 nm and 540 nm. U.S. Pat. No. 5,339,197 discloses a pellicle which exhibits peak transmittance characteristics at the G, H and I lines. While the disclosed pellicle has a peak transmission at 365 nm and 436 nm, the I-line and G-line peaks are relatively narrow due to the presence of three peaks within the range of 350 nm and 450 nm. A thinner pellicle which has broader high transmittance characteristics for wavelengths surrounding the I and G lines would improve the process margin by allowing a greater percentage of the available I-line or G-line illumination to be used during the photolithography process.
Various pellicles available in the art employ an anti-reflective coating to improve transmission and reduce the interference effects of the pellicle membrane. The pellicle disclosed in U.S. Pat. No. 5,339,197 includes an optical membrane with a refractive index of about 1.5 covered on both sides with a single-layer anti-reflective coating having an index of refraction of about 1.38. The anti-reflective coating reduces the amount of light which is reflected by the pellicle due to the destructive interferences between air and the anti-reflective coating and between the anti-reflective coating and the membrane. However, partial reflection occurs between maximum transmission wavelengths. Another type of pellicle employs an intermediate anti-reflective layer of materials such as Novalac, poly vinylphenol, or polystyrene and an outer anti-reflective layer of a fluorinated polymer. The high refractive index of the intermediate layer, about 1.68, improves the effectiveness of the anti-reflective material. However, the high index film may degrade under UV illumination, resulting in discoloration or reducing the total transmission. A pellicle having an anti-reflective coating which provides an improved, broad transmission curve is desirable.
OBJECTS AND SUMMARY OF THE INVENTION
it is a primary object of this invention to provide a pellicle for protecting photomasks, reticles and the like from particulate contaminants.
It is a further object of the invention to provide a pellicle having an anti-reflective coating having broad transmission characteristics.
It is another object of the invention to provide a pellicle having a multi-layer anti-reflective coating which minimizes reflection from the pellicle.
It is another object of the invention to provide a pellicle having a peak transmission of at least 98 percent at about 365 nm and 436 nm.
It is yet another object of the invention to provide a pellicle having a peak transmission of 99 percent or more for a substantial amount of the output produced by I-line and G-line Mercury arc lamps.
It is a more general object of the invention to provide a pellicle having high transmission characteristics, minimal interference effects and the ability to withstand film degradation and deterioration over time.
In summary, this invention provides an optical pellicle particularly suitable for protecting photomasks, reticles and the like. The optical pellicle includes a membrane having maximum peak transmissions at 365 nm and 436 nm. The peaks are broad, transmitting 99 percent or more of light having a wavelength corresponding to the maximum output range of 361-369 nm and 430 nm and 440 nm of the Mercury arc lamps. The membrane has a thickness of about 0.61 μm±0.5 μm. An anti-reflective coating is applied to at least one surface of the membrane to improve transmission.
In one modification of the invention, the anti-reflective coating includes an outer layer and at least one intermediate layer between the outer layer and the membrane. The intermediate layer has a refractive index which is less than the index of the membrane and the outer layer has a refractive index which is less than the refractive index of the intermediate layer.
Additional objects and features of the invention will be more readily apparent from the following detailed description and appended claims when taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a top plan view of a pellicle in accordance with the invention, shown mounted to a pellicle frame which is mounted to a photomask.
FIG. 1B is an enlarged, fragmentary cross sectional view taken along line 1B--1B of FIG. 1A.
FIG. 2 is a fragmentary, schematic side elevational view of the pellicle of FIG. 1A.
FIG. 3 is a schematic graph showing transmittance versus wavelength of the pellicle of FIG. 1A.
FIG. 4 is a fragmentary, schematic side elevational view of another embodiment of the invention.
FIG. 5 is a schematic graph showing transmittance versus wavelength of the pellicle of FIG. 4.
FIG. 6 is a fragmentary, schematic side elevational view of still another embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the preferred embodiment of the invention, which is illustrated in the accompanying figures. Turning now to the drawings, wherein like components are designated by like reference numerals throughout the various figures, attention is directed to FIGS. 1A-3.
FIGS. 1A-3 show a pellicle which is particularly suitable for protecting the surface of a photomask or reticle from particulate contamination and removing particles from the focal plane of the photomask pattern. The pellicle 10 is mounted to a frame 12 which is mounted to a photomask or reticle 14, enclosing the photomask pattern (not shown) within the frame 12. The shape of the frame 12, and the pellicle attached to the frame, is subject to considerable variation depending upon the configuration of the photomask and the constraints of the photolithography equipment.
As is shown particularly in FIG. 2, pellicle 10 includes an optical membrane 20. The optical membrane is formed of a material such as nitrocellulose, cellulose acetate or another suitable deep UV film. In the present embodiment, the optical membrane has a wavelength transmission spectrum with two consecutive maximum transmission peaks--the first occurring at a wavelength of 365 nm and the second occurring at a wavelength of 436 nm. Providing a membrane having a peak transmission at both the 365 nm and 436 nm wavelengths allows the user to employ the same pellicle for I-line and G-line photolithography equipment. The peaks are relatively broad due to the thickness of the optical membrane 20. The optical membrane transmits a high percentage of maximum output of I-line and G-line Mercury arc lamps, which typically falls within the ranges of 361 nm to 369 nm and 430 nm to 442 nm.
An anti-reflective coating 22 substantially covers the optical membrane 20. In the preferred embodiment, the coating 22 is applied to both the upper and lower surfaces of the optical membrane 20 as shown in FIG. 2. Although not shown, in other modifications of the invention the anti-reflective coating may be applied to only one surface of the optical membrane if desired. For optimum protection in reducing reflection interference, the coating 22 preferably substantially covers the entire surface of the optical membrane. The anti-reflective coating reduces the reflectivity of the membrane and improves the transmission of the membrane 20. In the present embodiment, the anti-reflective coating is formed of a suitable material such as a fluorinated polymer having an index of refraction of about 1.33-1.40.
As is known in the art, the optical membrane may be formed by spin coating a polymer-solvent mixture onto a rotating surface. The membrane thickness depends upon the viscosity of the polymer-solvent mixture and the speed and acceleration of the rotating surface. Preferably, the membrane thickness is substantially uniform across the entire membrane. For membranes having a thickness of about 0.61 μm±0.5 μm, the polymer-solvent mixture has a relatively low viscosity on the order of 10 cps. The low viscosity of the mixture offers the advantages of greater control over the thickness and uniformity of the membrane and more efficient filtration. Although thicker films are stronger than the 0.56-0.66 μm film, the optical membrane 20 of the present invention is of sufficient strength to withstand normal handling and inspection conditions. Because of the wider peak-to-peak spacing of the transmission spectrum, changes in membrane thickness due to water absorption or other factors will have a minimal effect on the maximum transmittance of the pellicle. The anti-reflective coating is formed by mixing the fluorinated polymer with a fluorinated solvent which will not dissolve the membrane 20 applying the coating to the exposed surface by spin coating. The anti-reflective coating 22 preferably has a thickness of about 730 ű100 Å.
FIG. 3 shows the transmission spectrum for the pellicle 10 of the present invention. As is shown in FIG. 3, the pellicle 10 transmits about 99 percent or more of the light having a wavelength of about 360 nm to 378 nm, and about 99 percent or more of the light having a wavelength of about 420 nm to 444 nm. Thus, maximum output of the I-line and G-line Mercury lamps, which is typically in the range of 361 nm to 369 nm and 430 to 442 nm, is transmitted by the pellicle 10. The pellicle 10 of the present invention significantly improves process margins by transmitting a greater percentage of the usable light produced by both I-line and G-line Mercury arc lamps.
FIGS. 4 and 5 show an embodiment of the present invention in which the pellicle 10a includes a multiple-layer anti-reflective coating to further reduce the reflectivity of the film. As is shown in FIG. 4, the anti-reflective coating 22a includes at least one intermediate layer 34 and an outer layer 36. Although only one intermediate layer is shown in FIG. 4, it will be understood that the multiple layer anti-reflective coating may include two or more intermediate layers if desired.
The materials of the optical membrane 20a and the intermediate layer 34 and outer layer 36 of the anti-reflective coating 22a are selected so that the refractive index decreases from the optical membrane 20a to the ambient air adjacent the outer layer 36. The refractive index of the optical membrane is preferably within the range of 1.4 to 1.6, with a nitrocellulose membrane having an index of 1.5. The intermediate layer is formed of a material having a refractive index of about 1.40 to 1.50, while the outer layer is formed of a material having a refractive index of about 1.33 to 1.40. If more than one intermediate layer is employed, the refractive index of the innermost intermediate layer is preferably higher than the next succeeding layer. When an anti-reflective coating is applied to the optical membrane, partial reflection and refraction occurs at the air-coating interface and the coating-membrane coating because of the differences in the refractive index of the different materials. With the anti-reflective coating 22a of the present invention, the difference in refractive index is divided into several smaller steps, reducing the amount of refraction and reflection at each interface. Using two or more anti-reflective layers with a successively increasing refractive index substantially improves the transmission of pellicle 10a.
Suitable materials for the intermediate layer 34 include silane polymers, siloxane polymers, starch derivative polymers and the like. The polymer is mixed with a solvent of alcohol, water or another suitable solvent base which will not dissolve the membrane 20a and applied to the surface of the optical membrane by spin coating. Unlike the higher index intermediate layers employed in the prior art, the materials used for intermediate layer 34 offers the advantage of substantial stability to UV light due to the absence of un-saturated carbon-carbon double bonds which may absorb near UV radiation and degrade the integrity of the anti-reflective coating. The outer layer 36 is formed of a lower index material such as a fluorinated polymer. The lower index polymer is mixed with a fluorinated solvent which will not dissolve the membrane 20 or the intermediate layer 34 and applied to the exposed surface of the intermediate layer 34 by spin coating. The intermediate layer may have a thickness up to about 2000 Å or the intermediate layer may be omitted as in the previously described embodiment. The thickness of each layer is preferably about 730 ű100 Å. Preferably, the thickness of the intermediate layer 34 and the outer layer 36 is substantially uniform.
FIG. 5 illustrates a schematic graphical illustration showing the transmittance of the pellicle 10 versus wavelength. The pellicle 10a includes an optical membrane 20a with a thickness of about 0.65 μm, an intermediate layer 34 formed of a low refractive index polymer and having a thickness of about 0.06 μm, and an outer later 36 formed of fluorinated polymer and having a thickness of about 0.07 μm. Although an optical membrane thickness of about 0.56 to 0.66 is preferred for its transmission spectrum with broad peaks at 365 nm and 436 nm, it is to be understood that the multiple layer anti-reflective coating 22a may also be of advantage with membranes of other thicknesses. As is shown in FIG. 5, the pellicle 10a has a transmittance greater than 99 percent for wavelengths in the range of 365±10 nm and 436±10 nm. Unlike the pellicles of the prior art, the pellicle 10a of the present invention has a high transmittance over relatively broad peaks corresponding to the wavelengths of 365 nm and 436 nm. The pellicle 10a thereby transmits a high percentage of the light produced by the I-line and G-line Mercury arc lamps, allowing much of the available light to be efficiently used during the photolithography process.
FIG. 6 illustrates another embodiment of the invention. Pellicle 10b generally includes an optical membrane 20b having a thickness of about 0.63 μm±0.5 μm. The membrane 20b is formed of a suitable membrane such as nitrocellulose, cellulose acetate or another suitable deep UV film. One surface of the optical membrane 20b is covered by an anti-reflective coating 22b having at least one intermediate layer 34b and an outer layer 36b. As previously described, the intermediate layer has a lower refractive index than the membrane 20b, and the outer layer 36b has a lower refractive index than the intermediate layer 34b. The anti-reflective coating 22b preferably has a thickness of about 730 Å. As with the previously described embodiment, the membrane 20b and the layers 34b and 36b are formed by spin coating, with the viscosity of the polymer/solvent solution and rotation of the rotating surface being controlled to achieve the desired thickness.
Except as set forth above, the modifications of FIGS. 4-6 resemble those of the preceding modifications and the same reference numerals followed by the letters "a" and "b", respectively, are used to designate corresponding parts.
The present invention provides a pellicle which is particularly suitable for use with photomask patterns which are subjected to I-line and G-line wavelengths during the photolithography process. As is shown by the broad peaks in FIGS. 3 and 5, the pellicle has a transmittance greater than 99 percent for several wavelengths in the range of 365 nm and 436 nm, improving production efficiency by using more of the available light. Reflection and refraction between at the interface between different materials is substantially reduced with the intermediate and outer layers of the anti-reflective coating of the present invention. The multi-layer anti-reflective coating of the present invention also provides more complete protection against reflection. | An optical pellicle and method of forming an optical pellicle. The pellicle includes a membrane and an anti-reflective coating covering at least one of the membrane surfaces. The membrane has a wavelength transmission pattern with consecutive first and second maximum transmission peaks where the first maximum transmssion peak corresponds to a wavelength of 365 nm and the second maximum transmission peak corresponds to a wavelength of 436 nm. The pellicle transits at least 99 percent of light striking said pellicle having a wavelength of about 361 nm to 369 nm and at least 99 percent of light striking said pellicle having a wavelength of about 430 nm to 442 nm. In one embodiment, the anti-reflective coating includes at least one intermediate layer having a refractive index less than the refractive index of the membrane, and an outer layer having a refractive index less than the refractive index of the intermediate layer. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the priority, under 35 U.S.C. §119, of German patent application DE 10 2007 035 350.4, filed Jul. 27, 2007; the prior application is herewith incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to a feed line for a hydraulic system, in particular of a motor vehicle, such as, for example, a power steering system. The invention also pertains to a hydraulic system provided with such a feed line, in particular a hydraulic system for a motor vehicle.
It is known that, under unfavorable conditions, in hydraulic systems the hydrostatic pressure of the hydraulic medium may locally undershoot the vapor pressure of the hydraulic medium at the prevailing temperature, thus often leading to cavitation phenomena or at least to disturbing noises. In specific driving situations, for example when the steering wheel is quickly shifted to the steering stops during parking, the risk of the occurrence of cavitation is increased, because the pressure in the hydraulic steering system of the vehicle abruptly changes locally on account of the stress on the vehicle wheels which is caused by the forces.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a hydraulic feed line and a corresponding hydraulic system which overcome the above-mentioned disadvantages of the heretofore-known devices and methods of this general type and which safely prevent cavitation from occurring.
With the foregoing and other objects in view there is provided, in accordance with the invention, a feed line for a hydraulic system, in particular in a motor vehicle. The hydraulic feed line comprises:
a dimensionally variable body forming the feed line, at least over a part of a longitudinal extent thereof, the dimensionally variable body having an elastically deformable body wall, at least in regions thereof;
wherein, when hydraulic medium flow passes through the dimensionally variable body, a cross section of the dimensionally variable body is varied as a function of a pressure of the hydraulic medium.
In other words, the objects of the invention are achieved in that the feed line is formed, at least over part of its length, by a dimensionally variable body, the body wall of which is elastically deformable, at least in regions. When the hydraulic medium passes through the dimensionally variable body, the cross section of the dimensionally variable body can be varied as a function of the pressure of the hydraulic medium.
The dimensionally variable body may basically be configured as desired, and may be configured, for example, as a flexible, elastically deformable hose body.
In one embodiment of the invention, the dimensionally variable body is surrounded by an outer body.
In a preferred embodiment of the invention, the outer body may basically be formed as desired, for example as an outer hose.
According to a refinement of the invention, the hose body is produced from a comparatively easily expandable material, while the outer body is produced from an only slightly expandable or non-expandable material. The outer body can consequently offer counter-forces to the pressure forces exerted on the inside of the outer body by the expandable hose body and can absorb higher pressure forces, as compared with the hose body.
According to a refinement of the invention, in the position of rest, that is to say without the action of pressure by the hydraulic medium (i.e., substantial pressure equilibrium between the exterior pressure and the pressure of the hydraulic medium), the hose body has, at least over part of its longitudinal extent, an initial cross section of flat shape and/or of approximately oval shape. The flat or oval shape approaches a circular shape during the expansion of the hose body as a result of the increasing action of pressure by the hydraulic medium flowing through the hose body. The term “flat” means in this text that the cross section has an extent appreciably lower (for example, by the factor two) in one direction of space running perpendicularly with respect to the axial direction of the hose body than in the other direction of space running perpendicularly with respect to the axial direction of the hose body.
Advantageously, the hose body may have, at least over part of its length, a substantially wavy or wave-shaped cross section, that is an axial corrugation. In another embodiment of the invention, the hose body has, at least over part of its longitudinal extent, an substantially star-shaped cross section.
Basically any other suitable shapes may, of course, also be considered for the cross-sectional shape of the hose body.
For example, the hose body is produced from a material which comprises rubber. If the hose body is of multilayer form, at least one layer of the hose body is produced from a material which comprises rubber.
For example, the outer hose is produced from a material which comprises an elastomer. If the outer hose is of multilayer form, at least one layer of the outer hose is produced from a material which comprises an elastomer. For example, the elastomer referred to comprises chlorosulfonated polyethylene (CSM).
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in feed line for a hydraulic system and hydraulic system, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a diagrammatic longitudinal section through a portion of a feed line according to the invention;
FIG. 2 is a diagrammatic cross section taken through the hose body of the structure of FIG. 1 in the position of rest;
FIG. 3 is a similar view of the hose body of FIG. 2 in the pressure-loaded, expanded state; and
FIG. 4 is a cross section through a hose body of star-shaped cross section surrounded by an outer hose.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, the diagrammatic illustration shows a section along the longitudinal direction of a feed line 1 according to the invention. The feed line 1 is an integral part of a hydraulic system with a hydraulic volume as an accumulator. A hose body 2 of a first exemplary embodiment (designated below briefly as a “first hose body”) is integrated, pressure-tight, into the feed line 1 . In the position of rest, the first hose body 2 possesses an oval cross-sectional shape. The first hose body 2 is formed from a flexible, elastically deformable material, extends between a first rigid feed line tube 3 (illustrated only partially) and a second rigid feed line tube 4 (likewise illustrated only partially). It is fluidically connected between the two feed line tubes 3 , 4 . The feed line tubes 3 , 4 have in each case a circular cross section.
The hose body is surrounded by an outer hose 5 of circular cross section. The gap formed between the first hose body and the outer hose is filled with air.
The two feed line tubes 3 , 4 are provided, at their ends that are disposed inside the outer hose 5 and facing one another, with a first connection part 30 and with a second connection part 40 , respectively. The two connection parts 30 , 40 are in each case of hollow-cylindrical design. The first hose body 2 , with its first longitudinal end 20 , sealingly surrounds the outer circumference of the first connection part 30 . Correspondingly, the first hose body 2 , with its second longitudinal end 21 , sealingly surrounds the outer circumference of the second connection part 40 .
The first hose body 2 is deformed under the influence of the hydrostatic pressure of the hydraulic medium flowing through the first hose body 2 . In this case, with an increasing pressure, the first hose body 2 expands in the radial direction from an initial shape, which the first hose body 2 assumes in the position of repose, and thus experiences an increase in volume. When the pressure in the hydraulic system falls again, the first hose body 2 contracts and endeavors to resume its original initial shape. During the contraction of the first hose body 2 , hydraulic medium is discharged out of the first hose body 2 into the feed line tubes 3 , 4 , with the result that the undershooting of the vapor pressure in the feed line tubes 3 , 4 is counteracted. To some extent, the first hose body 2 forms an accumulator for a compensating quantity of hydraulic medium for the compensation of pressure fluctuations in the hydraulic system.
A flexible, elastically deformable hose body 2 and a functionally appropriate volume adaptation of the hose body 2 may also be provided in that a twist angle deviating from what is known as the neutral angle is selected for the hose body 2 . The neutral angle amounts to approximately 54.7° for the twist angle. The neutral angle is characterized by a force equilibrium between axial and tangential forces. The twist angle designates the angle between the longitudinal axis of the hose body 2 and the individual fibers of the braiding. A functionally appropriate volume flexibility of the hose body 2 arises in the case of a twist angle of between preferably approximately 38° and 48°. The twist angle may amount, for example, to approximately 43°.
The outer hose 5 disposed coaxially with the two feed line tubes 3 , 4 and with the hose body 2 has a higher pressure loadability and a higher rigidity, as compared with the first hose body 2 . The outer hose 5 can consequently offer counterforces to the radial pressure forces exerted by the expanding hose body on the cylindrical inner wall of the outer body and can absorb higher pressure forces, as compared with the hose body 2 .
FIG. 2 shows a cross section of the first hose body 2 in the position of rest. In the position of rest, the cross section of the first hose body 2 has an oval shape which, as compared with a round cross-sectional shape in the position of rest, gives the hose body 2 particularly more advantageous elastic properties which are effected, for example, in high flexibility during the contraction of the hose body.
FIG. 3 shows a cross section of the first hose body 2 in the expanded state. The cross section then has an approximately circular shape.
FIG. 4 shows a cross section through a second hose body 2 ′ and an outer hose 5 surrounding the latter. The second hose body 2 ′ has a wavy (undulating, corrugated) cross section similar to an accordion bellows shape which gives the second hose body 2 ′ particularly advantageous elastic properties, such as, for example, the ability, even under comparatively low pressures, to react with a relatively high expansion. The longitudinal elevations 6 , in each case arranged, offset to one another, circularly at the same angle, extend in the radial direction outward from the core part 7 and in the axial direction, parallel to one another, over the entire longitudinal extent of the second hose body 2 ′. The core part 7 , having an annular cross section, is delimited inwardly by a cylindrical inner face. The second hose body 2 ′ may also have a star-shaped cross section.
The design variances of the hose body 2 or 2 ′ which are shown in FIGS. 1 to 4 are suitable both for use in conjunction with an outer hose, that is to say in a so-called hose-in-hose variant, and for use as a shaped hose without a corresponding further hose, for example outer hose 5 . | The feed line for a hydraulic system, in particular of a motor vehicle, is formed, at least over part of its longitudinal extent, by a dimensionally variable body. The wall of the dimensionally variable body is elastically deformable, at least in regions, so that, when the flow passes through the dimensionally variable body, the cross section of the dimensionally variable body can be varied as a function of the pressure of the hydraulic medium. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to a process for producing an insulated rectangular (flat) wire by applying an insulating material onto a round conductor, baking the insulating coating, and rolling the insulated wire into a rectangular or flat shape. The present invention relates particularly to a process for producing an insulated rectangular wire having excellent insulating properties that adapt the wire to edgewise winding.
Rectangular insulated wire manufactured by drawing round insulated wire has been extensively used for voice coils of loudspeakers. The range of application of such wire has recently been expanded to include drive motors for computer-associated equipment. Insulated rectangular wires may be wound into a coil flatwise, but more frequently, they are wound edgewise. Rectangular insulated wires for use in coils must meet the following requirements: (1) Each turn of the coil has a smooth and even surface. This requirement imposes a maximum limit of the amount of variation in the width of the flat insulated wire. (2) The insulating coating is crack free and has no part where the conductor is exposed. This means that there should be no breakage of the insulating coating when pressure is applied in the rolling operation, and that surface flaws in the conductor should not cause cracks in the insulating coating due to mechanical stress occurring during the winding of the insulated wire into a coil. (3) The insulating coating adheres sufficiently strongly to the conductor that no separation of the coating occurs while the round insulated wire is shaped into a rectangular form under a very high pressure.
The present inventors previously filed a patent application for a process for producing a rectangular insulated wire having a very high precision in the dimension of width by applying a coating of an insulating material onto a rigid conductor and baking the insulating coating. However, no satisfactory solutions have been proposed for meeting requirements (2) and (3). That is, if a round conductor has a surface flaw, the insulating coating over that flaw may crack during the process of rolling the round wire into a flat shape. Even a very small flaw in the conductor surface can cause such a defect when the rectangular insulated wire is wound into a coil edgewise. That is, the surface area of each turn of the coil facing the outside is expanded during winding so that the insulating coating tends to crack. On the other hand, the surfaces facing the center of the coil shrink in area as the coil is wound, and hence the possibility of cracking the coating is much smaller than in the coating facing outward. Cracks in the insulating coating unavoidably deteriorate the electrical properties of the coil and impair its reliability and service life by an appreciable degree. Therefore, an improved method for producing a rectangular insulated wire having no cracks in the insulating coating has long been desired.
In order to produce a flat insulated wire having a higher width to thickness ratio, the round wire must be rolled at an increased reduction ratio, but then the strength of adhesion of the insulating coating to the underlying conductor is decreased so as to increase the possibility of separation of the insulating coating from the conductor. If the width to thickness ratio of the wire exceeds about five, the round wire must be subjected to at least two roll passes. Doing so, however, further weakens the adhesion of the insulating coating to the conductor and increases the chance of separation of the insulating coating.
In order to solve these problems, the present inventors have made various studies on a process for producing a rectangular insulated wire by rolling a round wire without causing cracks or separation of the insulating coating from the conductor.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a process for producing a rectangular insulated wire of good quality by applying an insulating coating to a round conductor that has been free of surface flaws and deposits, baking the insulating coating, and rolling the round insulated wire into a rectangular shape.
More specifically, the process used a tandem-drawing zone, an electrolytic cleaning apparatus, a coating applicator and a baking chamber. By passing a round conductor through the drawing zone, the conductor is not only reduced in diameter but also free of surface defects such as checks, laps, slivers, cracks and streaks. The drawn conductor is then passed into the electrolytic cleaning section where the wire is cleaned of oil or metal dust that has built up during the drawing operation. Subsequently, the conductor is fed into the applicator zone where the insulating coating is applied to the conductor, and the wire is then passed through the baking chamber. The resulting round insulated wire is then given at least one roll pass, thereby forming a rectangular insulated wire.
The round insulated wire obtained as an intermediate product will cause no cracking in the insulating coating during the subsequent rolling. The final rectangular wire will also cause no cracking even when it is wound into a coil edgewise, and hence is free from the problem of exposing the conductor. As a further advantage, by removing all foreign material such as oil and metal dust from the conductor surface in the electrolytic cleaning step, a rectangular insulated wire having no possibility of separation of the insulating coating from the conductor is provided.
BRIEF DESCRIPTION OF THE DRAWING
The single drawing FIGURE is a schematic diagram illustrating a process for producing a round insulated wire from which a rectangular insulated wire according to the present invention is manufactured.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the processing line shown in the drawing, a round conductor 2 on a supply reel 1 is unwound and fed into a tandem-drawing zone 3. The surface of this conductor has many microscopic flaws that have been introduced in the predrawing steps due either to slippage on the capstan surface or to contact with the barrel or flanges of take-up reels. Upon close analysis, most of these flaws have depths and widths ranging from 3 to 20 μm, and lengths ranging from as small as 2 μm to as large as several meters.
The present inventors have examined the relationship between the size of the conductor surface flaws and the possibility of cracking that occurs in the insulating coating during rolling and found that surface flaws having a depth and width of 3 μm or more increase the chance of subsequent cracking in the insulating coating. With this in mind, the present inventors have made intensive efforts to eliminate surface flaws whose depth and width were 3 μm or larger. Some conductors have surface flaws that exceed 20 μm in deptn and width, but such flaws can be avoided by better workmanship in the predrawing steps.
In order to eliminate the formation of surface flaws whose depth and width are in the range of 3 to 20 μm, the present invention uses a tandem-drawing machine 3 which has a single die 5 through which the round conductor is passed once. The wire is subsequently forwarded to the next stage by means of a capstan 6. When the wire, which has an initial diameter of D 1 , is drawn down to a size of D 2 by being passed through the single die, the reduction ratio is given by:
(D.sub.1.sup.2 -D.sub.2.sup.2)/D.sub.1.sup.2 ×100.
Elimination of surface flaws ranging in size from 3 to 20 μm requires careful control over the reduction ratio. For example, if one wants to draw three copper wires (0.60 mm.sup.φ) having surface flaws in the conductor of depths of 5, 10 and 20 μm, respectively, and obtain products where the maximum flaw size is less than 3 μm, it is necessary to perform a single drawing operation to provide wire diameters of about 0.585, 0.560 and 0.550 mm. These correspond to reduction ratio of 5, 13 and 16%. A higher reduction ratio is effective in removing larger flaws. However, for the process of the present invention (which features a single drawing operation) a reduction ratio higher than 25% should be avoided because this requires an excessively great drawdown force, which increases the chance of formation of further surface flaws in the conductor as it is guided in contact with the capstan.
The present invention uses only one drawing die 5 in order to avoid slippage of the conductor 2 with respect to the capstan 6 which may result in the formation of further surface flaws on the conductor. If two or more dies are used, a capstan is necessary between each die; however, it is very difficult to otain complete agreement between the peripheral speed of the capstan and the linear speed of the conductor, the latter being determined by the diameter of the die orifice. If there is a difference between the linear speed of the conductor and the peripheral speed of the capstan, the conductor will slip on the capstan surface, which may cause further flaws to develope in the conductor surface. Therefore, the process of the present invention uses a single die for drawing the conductor.
Another feature of the drawing operation effected in the present invention is that a lubricant oil containing no metal dust is applied to the conductor. This is accomplished by providing a lubricating oil applicator 4 upstream of the die 5 with which clean lubricating oil free of metal dust is supplied to the conductor 2, thereby ensuring smooth passage of the conductor through the die. If recycled lubricating oil that contains the metal particles produced during the drawing operation is used the particles build up in the oil and may cause damage the surface of the conductor being drawn through the die. In order to prevent this, the conductor must be continuously supplied with clean lubricating oil containing no metal dust.
The material of the capstan 6 for guiding the conductor 7 coming out of the die is another important feature of the present invention. A particularly important point here is the hardness of the part of the capstan which contacts the running conductor. If that part of the capstan is made of a material harder than the conductor, the force acting between the two members, coupled with the hardness and surface roughness of the capstan, may cause development of further microscopic flaws on the conductor surface depending upon the amount and size of metal particles that build up on the conductor. According to experiments conducted by the present inventors, this problem can be avoided by using a capstan which is made of a material softer than the conductor.
Any practical material that is softer than the conductor to be drawn may be used for the capstan 6. Suitable examples include general and engineering plastics such as styrene resins, polyvinyl chloride, polyethylene, polypropylene, nylon 6, nylon 66, nylon 12, polyacetal, polycarbonate, polysulfone, phenoxy resins, phenolic resins, melamine resins, silicone resins, urethane resins, epoxy resins, polyester resins, urea resins and fluorine resins, as well as mixture or composites of these plastics. They may be filled with suitable additives. Other suitable capstan materials are synthetic rubbers such as silicone rubber, fluorine rubber, urethane rubber, acrylic rubber, polybutadiene, butadiene-styrene rubber, polychloroprene, polyisobutylene, and isobutylene-isoprene rubber.
These plastics and rubbers may be directly processed into the desired shape of the capstan. Alternatively, they may be used as the lining of the surface of a capstan made of another material so as to protect the area which contacts the drawn conductor. The capstan may be made of any metal that is softer than the conductor. Needless to say, the surface of the capstan wears over time and must be renewed when a certain amount of wear has occurred.
Yet another important requirement of the present invention is that the surface of the conductor be kept clean. The conductor 7 emerging from the die 5 always carries on its surface a film of lubricating oil used in the drawing operation, and in addition, metal particles produced during the drawing step also build up on the conductor surface. Such as deposit of metal dust or lubricating oil may be reduced to some extent by eliminating flaws on the conductor surface, but this alone is not sufficient to eliminate such deposits completely. If an insulating coating is applied to a conductor surface which is not entirely free of metal dust or lubricating oil film, when the resulting insulating coating is baked, the coating will not adhere sufficiently strongly to the conductor and may separate therefrom during the subsequent rolling procedure.
In order to eliminate all deposits of metal dust and lubricating oil from the conductor surface, the present inventors have tried various methods of cleaning the conductor, and have found that electrolytic cleaning is the simplest and most effective method. Organic solvents, ultrasonic waves, alkalis or acids used independently or in combination proved less efficient than electrolytic means in cleaning the surface of the conductor. By applying electrolytic cleaning, the conductor surface can be completely cleaned of any deposit of lubricating oil and metal particles, and as a result, the adhesion of the insulating coating to the conductor is increased to such a level that very few areas occur where the insulating coating separates from the conductor, even if the round insulated wire is subjected to more than one roll passes. For the purpose of the present invention, the minimum current density at the conductor surface is 5 mA/mm 2 . Needless to say, the proper current density can be set at a value to suit the desired degree of cleaning.
After electrolytic cleaning, excess electrolyte on the conductor surface is washed away with warm water, and the conductor is subjected to the application and baking of an insulating coating. The so-prepared round insulated wire can be rolled into a rectangular shape without causing cracking in or separation of the insulating coating. Furthermore, the completed rectangular insulated wire can be wound into a coil edgewise without causing separation of the insulating coating from the conductor.
The process of the present invention is effective not only for producing a rectangular insulated wire by subjecting round insulated wire to one roll pass, but also for production using more than one roll pass. For example, the invention is particularly effective in producing rectangular insulated wire having a width to thickness ratio of five or more by subjecting round insulated wire to more than one roll pass.
The insulating coating used in the present invention is typically required to endure a heat treatment intended for softening the conductor. For this purpose, an insulating coating capable of resisting temperatures of 200° C. or higher may be prepared from a single layer of polyimide, polyamideimide, polyesterimide, polyesteramideimide or polyhydantoin, or a composite layer made of a combination of these polymers. If the conductor of the finished rectangular insulated wire need not be softened, insulating coating made of less heat-resistant (<200° C.) polymers such as polyester, polyurethane, polyvinyl formal and epoxy resins may also be used.
The present invention will hereunder be described in greater detail with reference to working and comparative examples, to which the scope of the invention is by no means limited.
COMPARATIVE EXAMPLE 1
A copper conductor (0.6 mm.sup.φ) was coated with a polyamideimide film which was baked to provide an insulating coating of a thickness of 0.015 mm. The resulting round insulated wire was rolled into a rectangular cross section (0.22 mm×1.00 mm), which was then passed through a softening chamber (450° C.). The rectangular insulated wire thus obtained was wound around a mandrel (50 mm.sup.φ) edgewise 50 turns, and then checked for cracking in the insulating coating with a magnifying glass (50×). Thereafter, the wire was subjected to a uniformity test (JIS C 3003) to determine the number of defective points for a sample length of 30 m. The wire was also checked for the occurrence of separation of the insulating coating from the conductor. The results are shown in Table 1.
COMPARATIVE EXAMPLE 2
A copper conductor (0.66 mm.sup.φ) was passed through a tandem-drawing machine containing a single die (orifice diameter: 0.60 mm). The reduction ratio was 17.4%. Before entering the die, the conductor was supplied with fresh lubricating oil. The drawn wire was guided out of the drawing machine by a ceramic capstan and fed into an electrolytic cleaning zone where the wire was cleaned of excess metal particles and lubricating oil. The electrolyte was a 1% aqueous solution of NaHCO 3 , and the voltage and current density were 30 volts and 5.5 mA/mm 2 , respectively. Excess electrolyte was washed from the conductor with warm water and a polyamideimide coating was applied to the cleaned conductor and baked. The so-prepared round wire with an insulating coating 15 μm thick was rolled into a rectangular shape (0.22 mm×1.00 mm). The wire was passed through a softening chamber (450° C.). The rectangular insulated wire thus obtained was wound around a mandrel (50 mm.sup.φ) edgewise 50 turns, and then checked for cracks in the insulating coating with a magnifying glass (50×). Thereafter, the wire was subjected to a uniformity test (JIS C 3003), and the number of defective points that occurred for a sample length of 30 m was determined. The wire was also checked for the occurrence of separation of the insulating coating from the conductor. The results are shown in Table 1.
COMPARATIVE EXAMPLE 3
An aluminum conductor (0.5 mm.sup.φ) was coated with a polyimide film which was baked to provide an insulating coating of a thickness of 0.012 mm. The resulting round insulated wire was rolled into a rectangular cross section (0.21 mm×0.86 mm), and subsequently passed through a softening chamber (450° C.). The rectangular insulated wire thus obtained was wound around a mandrel (50 mm.sup.φ) edgewise 50 turns, and then checked for cracks in the insulating coating with a magnifying glass (50×). Thereafter, the wire was subjected to a uniformity test (JIS C 3003), and the number of defective points that occurred in a sample length of 30 m was counted. The wire was also checked for the occurrence of separation of the insulating coating from the conductor. The results are shown in Table 1.
COMPARATIVE EXAMPLE 4
An aluminum conductor (0.54 mm.sup.φ) was passed through a tandem-drawing machine containing a single die (orifice diameter: 0.50 mm). The reduction ratio was 14.3%. Before entering the die, the conductor was supplied with fresh lubricating oil. The drawn wire was guided out of the drawing machine by a stainless steel capstan thermal-spray coated with METCO 444 (product of Daiichi Metco Co. of Japan) and fed into an electrolytic cleaning bath where the wire was cleaned of excess metal particles and lubricating oil. The electrolyte was a 1% aqueous solution of NaHCO 3 , and the voltage and current density were 30 volts and 5.5 mA/mm 2 , respectively. Excess electrolyte was washed from the conductor with warm water, and a polyimide coating was applied to the cleaned conductor and baked. The so-prepared round wire with an insulating coating of a thickness of 12 μm was rolled into a rectangular cross section (0.21 mm×0.86 mm), and the resulting wire was passed through a softening chamber (450° C.). The rectangular insulated wire thus obtained was wound around a mandrel (50 mm.sup.φ) edgewise 50 turns, and then checked for cracks in the insulating coating with a magnifying glass (50×). Thereafter, the wire was subjected to a uniformity test (JIS C 3003), and the numer of defective points that occurred in a sample length of 30 m was counted. The wire was also checked for the occurrence of separation of the insulating coating from the conductor. The results are shown in Table 1.
COMPARATIVE EXAMPLE 5
A rectangular insulated aluminum wire with a polyimide insulating coating was prepared as in Comparative Example 4, except that the capstan for guiding the conductor out of the drawing machine was made of stainless steel with a hard chromium plating. The characteristics of the soprepared rectangular wire are shown in Table 1.
EXAMPLE 1
A rectangular insulated copper wire with a polyamideimide coating was prepared as in Comparative Example 2, except that a copper conductor (0.62 mm.sup.φ) was drawn down at a reduction ratio of 6.3% and the capstan for guiding the conductor out of the drawing machine was made of polyvinyl chloride. The characteristics of the so-prepared rectangular wire are shown in Table 2.
EXAMPLE 2
A rectangular insulated copper wire with a polyamideimide coating was prepared as in Comparative Example 2, except that the capstan was made of steel with a urethane rubber lining. The characteristics of the so-prepared rectangular wire are shown in Table 2.
EXAMPLE 3
A rectangular insulated copper wire with a polyamideimide coating was prepared as in Comparative Example 2, except that the capstan was made of nylon 66. The characteristics of the so-prepared rectangular wire are shown in Table 2.
EXAMPLE 4
A rectangular insulated copper wire with a polyamideimide coating was prepared as in Comparative Example 2, except that the capstan was made of an epoxy resin. The characteristics of the so-prepared rectangular wire are shown in Table 2.
EXAMPLE 5
A rectangular insulated copper wire with a polyamideimide coating was prepared as in Comparative Example 2, except that the capstan was made of a melamine resin. The characteristics of the so-prepared rectangular wire are shown in Table 2.
EXAMPLE 6
A rectangular insulated copper wire with a polyamideimide coating was prepared as in Comparative Example 4, except that the capstan was made of polyvinyl chloride. The characteristics of the so-prepared rectangular wire are shown in Table 2.
EXAMPLE 7
A rectangular insulated copper wire with a polyamideimide coating was prepared as in Comparative Example 4, except that an aluminum conductor (0.55 mm.sup.φ) was drawn down at a reduction ratio of 17.4%, and the capstan was made of an ABS resin. The characteristics of the so-prepared rectangular wire are shown in Table 2.
EXAMPLE 8
A rectangular insulated copper wire with a polyamideimide coating was prepared as in Comparative Example 4, except that an aluminum conductor (0.55 mm.sup.φ) was drawn down at a reduction ratio of 17.4%, and the capstan was made of steel with a silicone rubber lining. The characteristics of the so-prepared rectangular wire are shown in Table 2.
EXAMPLE 9
A rectangular insulated copper wire with a polyamideimide coating was prepared as in Comparative Example 4, except that an aluminum conductor (0.55 mm.sup.φ) was drawn down at a reduction ratio of 17.4%, and the capstan was made of polyacetal. The characteristics of the so-prepared rectangular wire are shown in Table 2.
In Comparative Examples 1 and 3, rectangular insulated wires were prepared by rolling and softening round insulated wires according to the prior art method. These wires had cracks in the insulating coating, which separated from the conductor. In the uniformity test, as many as 110 defective points were found in the respective wires. These results were in sharp contrast with those of Examples 1 to 9 wherein rectangular insulated wire fabricted according to the present invention had no cracks in the insulating coating and no separation thereof from the conductor was observed. Furthermore, the number of defective points found in the uniformity test was very small and ranged from only 3 to 12. In Comparative Examples 2, 4 and 5, rectangular wires were prepared generally according to the scheme of the present invention. However, owing to the use of capstans harder than the conductor, many microscopic flaws developed in the conductor surface, causing cracks in the insulating coating though no separation of the insulating coating from the conductor occurred. The number of defective points found in the uniformity test ranged from 90 to 100, and was by no means smaller than that of the defective points found in Comparative Examples 1 and 3.
TABLE 1______________________________________ Comparative Example No. 1 2 3 4 5______________________________________Conductor exposed yes yes yes yes yesdue to cracking ininsulating coatingNo. of defective 100 100 90 95 90points found inuniformity test(30 V a.c. in3% aq. Na.sub.2 SO.sub.4)Separation of yes no yes no noinsulating coatingfrom conductor______________________________________
TABLE 2______________________________________ Example No. 1 2 3 4 5 6 7 8 9______________________________________Conductor exposed no no no no no no no no nodue to cracking ininsulating coatingNo. of defective 10 9 5 8 12 3 5 6 3points found inuniformity test(30 V a.c. in3% aq. Na.sub.2 SO.sub.4 )Separation of no no no no no no no no noinsulating coatingfrom conductor______________________________________ | A process for producing an insulated rectangular wire adapted for edgewise winding. A round wire of copper, copper alloy, aluminum or aluminum alloy is drawn through a die in a tandem-extrusion apparatus. The drawn wire is then electrolytically cleaned, following which an insulating coating is applied to the cleaned surface. The insulating coating is baked, and finally the insulated wire is subjected to at least one cycle of rolling. Preferably, the drawing is done with a single die and capstan to thereby remove any surface defects in the conductor having a size of 3 μm or greater. The capstan should be made of a material softer than the material of the conductor. Further, it is preferred that fresh lubricating oil containing no metal dust be applied to the surface of the conductor during the drawing process. | 1 |
RELATED APPLICATION
[0001] This application is a continuation of copending U.S. patent application Ser. No. 11/037,548 entitled “Devices, Systems and Methods for Treating Disorders of the Ear, Nose and Throat” filed on Jan. 18, 2005 which is a continuation-in-part of 1) U.S. patent application Ser. No. 10/829,917 entitled “Devices, Systems and Methods for Diagnosing and Treating Sinusitis and Other Disorders of the Ears, Nose and/or Throat” filed on Apr. 21, 2004, 2) U.S. patent application Ser. No. 10/912,578 entitled “Implantable Device and Methods for Delivering Drugs and Other Substances to Treat Sinusitis and Other Disorders” filed on Aug. 4, 2004 and 3) U.S. patent application Ser. No. 10/944,270 entitled “Apparatus and Methods for Dilating and Modifying Ostia of Paranasal Sinuses and Other Intranasal or Paranasal Structures” filed on Sep. 17, 2004, the entire disclosure of each such parent application being expressly incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to medical devices, systems and methods and more particularly to minimally invasive devices, systems and methods for treating sinusitis and other ear, nose & throat disorders.
BACKGROUND OF THE INVENTION
[0003] Surgical treatments for sinusitis and other disorders of the ear, nose and throat have evolved slowly over the years. In current clinical practice, functional endoscopic sinus surgery (FESS) is often used to treat sinusitis or other disorders where drainage of mucous is impaired and/or chronic infections are present. In FESS, an endoscope is inserted into the nose and, under visualization through the endoscope, the surgeon may remove diseased or hypertrophic tissue or bone and may enlarge the ostia of the sinuses to restore normal drainage of the sinuses. FESS procedures can be effective in the treatment of sinusitis and for the removal of tumors, polyps and other aberrant growths from the nose. Other endoscopic intranasal procedures have been used to remove pituitary tumors, to treat Graves disease (i.e., a complication of hyperthyroidism which results in protrusion of the eyes) and surgical repair of rare conditions wherein cerebrospinal fluid leaks into the nose (i.e., cerebrospinal fluid rhinorrhea).
[0004] In some instances, sinus and ENT surgery has been performed with the assistance of electronic navigation devices (i.e., “image-guided FESS”). In such image guided surgical procedures, integrated anatomical information is supplied through CT-scan images or other anatomical mapping data taken before the operation. Data from a preoperative CT scan or other anatomical mapping procedure is downloaded into a computer and special sensors known as localizers are attached to the surgical instruments. Thus, using the computer, the surgeon can ascertain, in three dimensions, the precise position of each localizer-equipped surgical instrument at any given point in time. This information, coupled with the visual observations made through the standard endoscope, can help the surgeon to carefully position the surgical instruments to avoid creating CSF leaks and to avoid causing damage to nerves or other critical structures.
[0005] Although FESS continues to be the gold standard therapy for severe sinuses, it has several shortfalls. Often patients complain of the post-operative pain and bleeding associated with the procedure, and a significant subset of patients remain symptomatic even after multiple surgeries. Since FESS is considered an option only for the most severe cases (those showing abnormalities under CT scan), a large population of patients exist that can neither tolerate the prescribed medications nor be considered candidates for surgery. Further, because the methodologies to assess sinus disease are primarily static measurements (CT, MRI), patients whose symptoms are episodic are often simply offered drug therapy when in fact underlying mechanical factors may play a significant role. To date, there is no mechanical therapy offered for these patients, and even though they may fail pharmaceutical therapies, no other course of action is indicated. This leaves a large population of patients in need of relief, unwilling or afraid to take steroids, but not sick enough to qualify for surgery.
[0006] Some experimental or investigational procedures have also been performed in an effort to treat sinusitis by methods that are less invasive and/or less damaging to ancillary tissues than FESS. For example, European physicians have reported the use of a hydrophilic guidewire and standard PTCA balloon catheter to treat restenosis of surgically created openings in diseased frontal sinuses and stenotic nasal conae. Göttmann, D., Strohm, M., Strecker, E. P., Karlsruhe, D. E., Balloon dilatation of Recurrent Ostial Oclusion of the Frontal Sinus, Abstract No. B-0453, European Congress of Radiology (2001); Strohm, M., Göttmann, D., Treatment of Stenoses of Upper Air Routes by Balloon Dilation, Proceeding of the 83 rd Annual Convention of the Association of West German ENT Physicians (1999). The interventions described in this abstract were conducted only on frontal sinuses that had previously been surgically modified and nasal conae. These techniques were not reported to be ueable for the treatment of sinus ostia that has not previously been surcically altered or ostia of sinuses other than the easily accessible frontal sinuses. Also, in these these reported cases, standard vascular guidewires and angioplasty balloon catheters were used. The techniques described in these publications have not been widely adopted by ENT surgeons, possibly due to the fact that they lacked important novel improvements and modifications as described in this patent application and prior U.S. patent application Ser. Nos. 10/829,917, 10/912,578 and 10/944,270, of which this application is a continuation-in-part.
[0007] Other methods and devices for sinus intervention using dilating balloons have been disclosed in U.S. Pat. No. 2,525,183 (Robison) and United States Patent Publication No. 2004/0064150 A1 (Becker). For example, U.S. Pat. No. 2,525,183 (Robison) discloses an inflatable pressure device which can be inserted following sinus surgery and inflated within the sinus. The patent does not disclose device designs and methods for flexibly navigating through the complex nasal anatomy to access the natural ostia of the sinuses. The discussion of balloon materials is also fairly limited to thin flexible materials like rubber which are most likely to be inadequate for dilating the bony ostia of the sinus.
[0008] United States patent publication number 2004/0064150 A1 (Becker) discloses balloon catheters formed of a stiff hypotube to be pushed into a sinus. The balloon catheters have a stiff hypotube with a fixed pre-set angle that enables them to be pushed into the sinus. In at least some procedures wherein it is desired to position the balloon catheter in the ostium of a paranasal sinus, it is necessary to advance the balloon catheter through complicated or tortuous anatomy in order to properly position the balloon catheter within the desired sinus ostium. Also, there is a degree of individual variation in the intranasal and paranasal anatomy of human beings, thus making it difficult to design a stiff-shaft balloon catheter that is optimally shaped for use in all individuals. Indeed, rigid catheters formed of hypotubes that have pre-set angles cannot be easily adjusted by the physician to different shapes to account for individual variations in the anatomy. In view of this, the Becker patent application describes the necessity of having available a set of balloon catheters, each having a particular fixed angle so that the physician can select the appropriate catheter for the patient's anatomy. The requirement to test multiple disposable catheters for fit is likely to be very expensive and impractical. Moreover, if such catheter are disposable items (e.g., not sterilizable and reusable) the need to test and discard a number of catheters before finding one that has the ideal bend angle could be rather expensive.
[0009] The prior art has not provided catheters, devices, systems and methods that are optimal for minimally invasive treatment of sinusitis, mucocysts, tumors, infections, hearing disorders, fractures, choanal atresia or other conditions of the paranasal sinuses, Eustachian tubes, Lachrymal ducts and other ear, nose, throat or mouth structures.
SUMMARY OF THE INVENTION
[0010] In general, the present invention provides methods, devices and systems for diagnosing and/or treating sinusitis, mucocysts, tumors, infections, hearing disorders, fractures, choanal atresia or other conditions of the paranasal sinuses, Eustachian tubes, (lachrymal ducts, ducts of salivary glands and other ear, nose, throat or mouth structures.
[0011] In accordance with the present invention, there are provided methods wherein one or more flexible catheters or other flexible elongate devices as described herein are inserted in to the nose, nasopharynx, paranasal sinus, Eustachian tubes, middle ear, lachrymal ducts, ducts of salvary glands or other anatomical passageways of the ear, nose, throat or mouth to perform an interventional or surgical procedure. Examples of procedures that may be performed using these flexible catheters or other flexible elongate devices include but are not limited to: delivering contrast medium; performing an imaging study, delivering a therapeutically effective amount of a therapeutic substance; implanting a stent or a tissue remodeling device, substance delivery implant or other therapeutic apparatus; cutting, ablating, debulking, cauterizing, heating, dilating or otherwise modifying tissue such as nasal polyps, abberant or enlarged tissue, abnormal tissue, etc.; grafting or implanting cells or tissue; reducing, setting, affixing or otherwise treating a fracture; delivering a gene or gene therapy preparation; cutting, ablating, debulking, cauterizing, heating, freezing, lasing, forming an osteotomy or trephination in or otherwise modifying bony or cartilaginous tissue within paranasal sinus, nasopharynx, Eustachian tube, middle ear, Lachrymal duct or elsewhere within the ear, nose, throat or mouth; remodeling or changing the shape, size or configuration of a sinus ostium or other anatomical structure that affects drainage from one or more paranasal sinuses; removing puss or aberrant matter from the paranasal sinus or elsewhere within the nose; scraping or otherwise removing cells that line the interior of a paranasal sinus; removing all or a portion of a tumor; removing a polyp; delivering histamine, an allergen or another substance that causes secretion of mucous by tissues within a paranasal sinus to permit assessment of drainage from the sinus etc.
[0012] Still further in accordance with the invention, there are provided novel access, stabilizing and occluding devices. They may be used to facilitate insertion of working devices such as endoscopes, guidewires, catheters (e.g. balloon catheters), tissue cutting or remodeling devices, sizing devices, biopsy devices, image-guided devices containing sensors or transmitters, electrosurgical devices, energy emitting devices, devices for injecting diagnostic or therapeutic agents, devices for implanting devices such as stents, substance eluting devices, substance delivery implants, etc. into the paranasal sinuses and other structures in the ear, nose, throat or mouth for performing some or all of the procedures described herein.
[0013] Still further in accordance with the invention, there are presented several modalities for navigation and imaging of the interventional devices within the nose, nasopharynx, paranasal sinuses, Eustachian tubes, middle ear, lachrymal ducts, ducts of salvary glands or other anatomical passageways of the ear, nose, throat or mouth using endoscopic, fluoroscopic, radiofrequency localization, electromagnetic and other radiative energy based imaging and navigation modalities. These imaging and navigation technologies may also be referenced by computer directly or indirectly to pre-existing or simultaneously created 3-D or 2-D data sets which help the doctor place the devices within the appropriate region of the anatomy.
[0014] Still further in accordance with the invention, there are provided methods for improving drainage from a paranasal sinus that has a natural ostium that has not previously been surgically altered, said method comprising the steps of: A) providing an elongate guide (e.g., a wire, rod, probe, guidewire, flexible member, malleable member, tube, cannula, catheter, stylets, etc.) and a dilator (e.g., a dilation catheter, balloon catheter, expandable member, etc.); B) advancing the elongate guide to a position within or near the ostium; C) using the elongate guide to advance the dilatior to a position where the dilator is within the ostium; and D) using the dilator to dilate the natural ostium. The dilation of the natural ostium may, in at least some cases, result in breaking or rearrangement of bone that underlies the mucosa of the ostium.
[0015] Still further in accordance with the invention, there is provided a method for treating a mucocyst or other or other flowable-substance-containing structure located within a paranasal sinus, said method comprising the steps of A) providing a penetrator that is useable to form an opening in the mucocyst or other flowable-substance-containing structure; B) providing a compressor useable to compress the mucocyst or other flowable-substance-containing structure after an opening has been formed therein by the penetrator such that its contents will be forced out of the opening formed by the penetrator; C) advancing the penetrator into the paranasal sinus and using the penetrator to form an opening in the mucocyst or other flowable-substance-containing structure; and D) positioning the compressor in the paranasal sinus and using the compressor to compress the mucocyst or other flowable-substance-containing structure such that its contents will be forced out of the opening formed by the penetrator.
[0016] Still further in accordance with the invention, there is provided a method for dilating a Eustachian tube in a human or animal subject, said method domprising the steps of: A) providing a a guide member (e.g., a guidewire) that is insertable through the nose and is advanceable into the Eustachian tube through the pharyngeal ostium of the Eustachian tube and a dilator that is advanceable over the guidewire and useable to dilate the Eustachian tube; B) inserting the guidewire into the Eustachian tube; C) advancing the dilator over the guide member and into the Eustachian tube; and D) using the dilator to dilate the Eustachian tube. In some embodiments of this method, the guide member (e.g., guidewire) may have an anchor (e.g., a balloon) for holding the guide member in a substantially fixed position within the Eustachian tube, thereby guarding against inadvertent advancement of the guide member or dilation catheter into the middle ear as may injure the bones of the middle ear. In some embodiments, marker(s) such as radiopaque markers may be provided on the guide memner and/or may be inserted into the adjacent ear canal next to the tympanic membrane to allow the operator to clearly view the location at which the Eustachian tube enters the middle ear, thereby further guarding against inadvertent advancement of the device(s) into the middle ear.
[0017] Still further in accordance with the invention, there is provided a method for modifying a bony structure within the nose or paranasal sinus human or animal subject, said method comprising the steps of: A) providing a direct viewing apparatus (e.g., a scope, rigid scope, flexible scope, camera, video camera, intranasal camera similar to an intraoral camera but sized for insertion into the nares or nasal cavity); B) inserting the direct viewing apparatus into the nose; C) advancing a guide device to a first location within the nasal cavity or paranasal sinus under direct viewing using the direct viewing apparatus; D) providing an indirect viewing apparatus (e.g., an imaging device, fluoroscope, fluoroscope with C-arm, magnetic resonance imaging device, tomographic device, CT scanner, electromagnetic navigational and/or guidance system, PET scanner, combination CT/PET scanner and optical coherence tomography device, etc.); E) advancing a working device (e.g., an endoscope, wire, probe, needle, catheter, balloon catheter, dilation catheter, dilator, balloon, tissue cutting or remodeling device, suction or irrigation device, imaging device, sizing device, biopsy device, image-guided device containing sensor or transmitter, electrosurgical device, energy emitting device such as laser, rf, etc., device for injecting diagnostic or therapeutic agent, device for implanting other articles such as stents, substance eluting or delivering device, implant, etc.) over the guide device to a second location location within the nasal cavity or paranasal sinus, under indirect viewing using the direct viewing apparatus; and F) using the working device to perform a therapeutic or diagnostic procedure.
[0018] Still further in accordance with the invention, there is provided a method for determining the position of a device within the body of a human or animal subject, said method comprising the steps of A) providing a device having an electromagnetic element (e.g., a sensor or electromagnetic coil) thereon; B) providing a plurality of fiducial markers which emit electromagnetic energy and an attachment substance or apparatus for removably attaching the fiducial markers to teeth, bones or other anatomical structures; C) using the attachment substance or apparatus to removably attach the fiducial markers to teeth, bones or other anatomical structures of the subject's body; D)performing an imaging procedure to obtain an image of a portion of the subject's body including the fiducial markers; and, thereafter, E) advancing the device into the subject's body and detecting the electromagnetic element on the device as well as the electromagnetic energy emitted by the fiducial markers; and F) using the image obtained in Step D and the information dectected in Step E to determine the current position of the device within the subject's body.
[0019] Further aspects, details and embodiments of the present invention will be understood by those of skill in the art upon reading the following detailed description of the invention and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 shows a schematic diagram of the general working environment of an example of a system for catheter-based minimally invasive sinus surgery being used to perform a sinus surgery on a human patient.
[0021] FIG. 1A shows a magnified view of region 1 A of FIG. 1 showing a system for catheter-based minimally invasive sinus surgery of a human patient.
[0022] FIG. 1B shows a perspective view of a treatment tray for catheter-based minimally invasive sinus surgery of a human patient.
[0023] FIG. 2A shows a portion of a stabilizing device comprising a stabilizing member.
[0024] FIGS. 2B-2D show various alternate embodiments of stabilizing member of FIG. 2A .
[0025] FIG. 2E-2G show perspective views of various embodiments of inflatable occluding devices.
[0026] FIGS. 3 A- 3 D′ show embodiments of stabilizing members comprising an adhesive element.
[0027] FIGS. 4A and 4B show perspective views of an occluding device in deflated and inflated states respectively.
[0028] FIG. 5 shows a perspective view of a guide catheter comprising a plastically deformable (malleable) region.
[0029] FIG. 6 shows a perspective view of a guide catheter comprising a lubricious layer.
[0030] FIG. 6A shows a crossectional view of the guide catheter of FIG. 6 through the plane 6 A- 6 A.
[0031] FIG. 7 shows perspective view of an embodiment of a guide catheter comprising a straight hypotube.
[0032] FIG. 7A shows a crossection of the guide catheter of FIG. 7 through plane 7 A- 7 A.
[0033] FIG. 8 shows perspective view of a second embodiment of a guide catheter comprising a straight hypotube.
[0034] FIG. 8A shows a crossection of the guide catheter of FIG. 8 through plane 8 A- 8 A.
[0035] FIG. 8B shows a crossection of the guide catheter of FIG. 8 through plane 8 B- 8 B.
[0036] FIG. 8C shows a perspective view of an embodiment of a guide catheter comprising a curved or bent hypotube to facilitate access to the frontal sinuses.
[0037] FIG. 8D shows a perspective view of a second embodiment of a guide catheter comprising a curved or bent hypotube to facilitate access to the sphenoid sinuses.
[0038] FIG. 8E shows a perspective view of an embodiment of a guide catheter comprising two bent or angled or curved regions to facilitate access to the maxillary sinuses.
[0039] FIG. 8F shows a perspective view of a second embodiment of a guide catheter comprising two bent or angled or curved regions and a hypotube to facilitate access to the maxillary sinuses.
[0040] FIG. 8G shows a coronal section of the paranasal anatomy showing a method of accessing a maxillary sinus ostium using the guide catheter of FIG. 8F .
[0041] FIG. 8H shows a sagittal section of the paranasal anatomy showing the method of FIG. 8G to access a maxillary sinus ostium using the guide catheter of FIG. 8F .
[0042] FIG. 8I shows a perspective view of an example of a guide catheter comprising a common proximal portion and a plurality of detachable distal tips.
[0043] FIG. 9 shows a perspective view of a set of devices to dilate or modify ostia or other openings in the ear, nose, throat or mouth structures.
[0044] FIG. 10 shows a perspective view of a probing device.
[0045] FIGS. 10A-10C show various steps of a method of using the probing device shown in FIG. 10 to access an anatomical region.
[0046] FIG. 11A shows a perspective view of a first embodiment of a dual balloon catheter that can be used to perform a diagnostic or therapeutic procedure.
[0047] FIG. 11B shows a perspective view of a second embodiment of a dual balloon catheter that can be used to perform a diagnostic or therapeutic procedure.
[0048] FIGS. 11C-11E show perspective views of third, fourth and fifth embodiments respectively of dual balloon catheters for dilating an anatomical region.
[0049] FIGS. 11F-11J show the various steps of a method of dilating an anatomical region using the catheter of FIG. 11D .
[0050] FIGS. 12A-12C show the various steps of a method of deploying a stent in the ear, nose, throat or mouth using a working catheter comprising a locating mechanism.
[0051] FIGS. 12D-12H show the various steps of a method of dilating an anatomical opening in the ear, nose, throat or mouth using a combination of a dilating device and an anchoring device.
[0052] FIG. 13 shows a perspective view of a dilating device comprising an electrode element to reduce restenosis.
[0053] FIG. 14 shows a perspective view of an embodiment of a balloon catheter comprising a sizing balloon and a dilating balloon.
[0054] FIG. 14A shows a crossectional view through the plane 14 A- 14 A of FIG. 14 .
[0055] FIGS. 14B-14D show the various steps of dilating an anatomical opening using the balloon catheter in FIG. 14 .
[0056] FIG. 15 shows a perspective view of a balloon catheter comprising a sleeve for delivering diagnostic or therapeutic agents.
[0057] FIG. 15A shows a crossectional view through plane 15 A- 15 A of FIG. 15 .
[0058] FIG. 16 shows a perspective view of a balloon catheter comprising one or more agent delivery reservoirs.
[0059] FIG. 16A shows a crossectional view through plane 16 A- 16 A of FIG. 16 .
[0060] FIG. 17 shows a perspective view of a balloon catheter comprising a balloon comprising one or more micropores.
[0061] FIG. 17A shows a crossectional view through the plane 17 A- 17 A of FIG. 17 .
[0062] FIG. 18 shows a balloon catheter comprising a balloon having an outer coating of diagnostic or therapeutic agents.
[0063] FIGS. 18A-18C show the steps of a method of using the balloon catheter of FIG. 18 to dilate an anatomical region.
[0064] FIG. 19A shows a perspective view of a lavage catheter.
[0065] FIG. 19B shows a crossectional view through the plane 19 B- 19 B of FIG. 19A .
[0066] FIG. 19C shows the method of operation of lavage catheter of FIG. 19A to lavage an anatomical region.
[0067] FIG. 20A shows a perspective view of the distal end of a second embodiment of a lavage catheter.
[0068] FIG. 20B shows a perspective view of the distal end of the lavage catheter of FIG. 20A introduced in an anatomical region.
[0069] FIG. 20C shows an embodiment of the lavage cattheter of FIG. 20A being used to lavage an anatomical region.
[0070] FIG. 20D shows a sagittal section of a human head showing the general working environment of the lavage devices of FIGS. 20A-20C .
[0071] FIG. 21 shows a perspective view of a cutting device comprising cutting jaws.
[0072] FIG. 21A shows a perspective view of the distal region of the cutting device of FIG. 21 wherein the cutting jaws are closed as seen from the distal end of the cutting device.
[0073] FIG. 21B shows a perspective view of one embodiment of the cutting jaws of the cutting device of FIG. 21 .
[0074] FIG. 21C shows a crossectional view of the cutting device in FIG. 21 through cutting plane 21 C- 21 C.
[0075] FIG. 22A shows a perspective view of an alternate embodiment of a device comprising cutting or gripping jaws.
[0076] FIG. 22B shows a perspective view of the device of FIG. 22A wherein the cutting or gripping jaws of the cutting device are in a closed configuration.
[0077] FIGS. 23A-23C show the various steps of a method of puncturing an anatomical region using a flexible, rotating drill shaft.
[0078] FIG. 23D shows a sectional view of an embodiment of a drilling device.
[0079] FIGS. 24A-24C show a sagittal section of an Ethmoid sinus showing various methods of treating Ethmoid sinus diseases by a minimally invasive approach.
[0080] FIGS. 24 A′- 24 A″″ show a method of creating drainage channels for sinus secretions in Ethmoid sinus.
[0081] FIG. 25A shows a perspective view of an embodiment of an ostium enlarger and/or microshaver.
[0082] FIG. 25B shows one embodiment of the device of FIG. 25A being used to remove tissue or matter.
[0083] FIG. 25C shown another embodiment of the device of FIG. 25A being used to shave tissue or matter.
[0084] FIG. 25D is an exploded view of the device of FIG. 25C .
[0085] FIGS. 26A-26C show various steps of a method of treating a mucocyst by a puncturing needle and a balloon catheter.
[0086] FIGS. 27A-27B show various steps of a method of treating a mucocyst by a balloon catheter comprising a deployable puncturing needle.
[0087] FIGS. 28A-28C show various embodiments of catheters comprising agent delivery needles.
[0088] FIG. 29A illustrates an embodiment of a displacement catheter to displace and remove secretions in an anatomical region.
[0089] FIG. 29B shows a sectional view of an anatomical region showing a method of displacing secretions by the displacement catheter of FIG. 29A .
[0090] FIG. 30 shows a perspective view of an embodiment of an ultrasonic drilling device.
[0091] FIGS. 30A-30B show a sectional view of an anatomical region showing a method of expanding an anatomical opening using the drilling device of FIG. 30 .
[0092] FIG. 31 shows a sectional view of an embodiment of a catheter for providing an internal cast for fractured bony cavities.
[0093] FIG. 31A shows a crossection through the outer balloon in the catheter of FIG. 31 through plane 31 A- 31 A.
[0094] FIGS. 31B-31D show various steps of a method of providing an internal cast for a fractured bony cavity using the catheter shown in FIG. 31
[0095] FIG. 32 shows an embodiment of a surgical navigation system comprising electromagnetic sensors.
[0096] FIG. 32A shows an enlarged view of region 32 A in FIG. 32 .
[0097] FIG. 33 shows a section of the anatomical region around a Eustachian tube (ET) showing a diagnostic or therapeutic procedure being performed by devices inserted through the pharyngeal ostium of the Eustachian tube.
[0098] FIG. 33A shows an enlarged view of region 33 A in FIG. 33 .
[0099] FIG. 33B shows a front view of a human head with a portion of the face removed to show an embodiment of a method of introducing a guidewire into a Eustachian tube.
[0100] FIGS. 34A-34D illustrate various examples of working elements that could be located on the diagnostic or therapeutic device in FIG. 33 .
[0101] FIG. 35 shows a perspective view of an embodiment of a guidewire comprising a sensor used for surgical navigation.
[0102] FIG. 35A shows an enlarged view of an embodiment of a low profile proximal region of the guidewire in FIG. 35 .
[0103] FIG. 35B shows a perspective view of a method of advancing a diagnostic or therapeutic device over the guidewire in FIG. 35 .
[0104] FIG. 35C shows a perspective view of an embodiment of a guidewire comprising a sensor having a diagnostic or therapeutic device preloaded on the guidewire.
[0105] FIG. 35D shows a perspective view of a second embodiment of a guidewire comprising a sensor having a diagnostic or therapeutic device preloaded on the guidewire.
DETAILED DESCRIPTION
[0106] The following detailed description, the accompanying drawings and the above-set-forth Brief Description of the Drawings are intended to describe some, but not necessarily all, examples or embodiments of the invention. The contents of this detailed description, the accompanying drawings and the above-set-forth Brief Description of the Drawings do not limit the scope of the invention in any way.
[0107] A number of the drawings in this patent application show anatomical structures of the ear, nose and throat. In general, these anatomical structures are labeled with the following reference letters:
Nasal Cavity NC Nasopharynx NP Frontal Sinus FS Frontal Sinus Ostium FSO Ethmoid Sinus ES Ethmoid Air Cells EAC Sphenoid Sinus SS Sphenoid Sinus Ostium SSO Maxillary Sinus MS Maxillary sinus ostium MSO Mucocyst MC Eustachian tube ET Cochlea Tympanic cavity TC Middle turbinate MT Inferior turbinate IT Uncinate UN
[0125] FIG. 1 shows a schematic diagram of the general working environment of an example of a system for catheter-based minimally invasive sinus surgery being used to perform a sinus surgery on a human patient. The human patient is treated by a working device 10 . Working device 10 may be connected to one or more auxiliary devices located on a treatment tray 12 . A C-arm fluoroscope 14 provides fluoroscopic visualization of anatomical regions during the procedure. An instrument console 16 comprising one or more functional modules 18 may also be present. Examples of functional modules that can be used with the invention are:
1. Suction pump for delivering a controlled amount of negative pressure or vacuum to a suction device, 2. Irrigation pump to deliver saline, antibiotic solution or other suitable irrigation medium, 3. Power module to supply power to drills or other electrical devices, 4. Storage modules for storing instruments, medications etc., 5. Energy delivery module to provide radiofrequency, laser, ultrasound or other therapeutic energy to a surgical device, 6. Fluoroscope, MRI, CT, Video, Endoscope or Camera or other imaging modules to connect or interact with devices used during various diagnostic or therapeutic procedures, 7. Display module e.g. a LCD, CRT or Holographic screen to display data from various modules such as an endoscope, fluoroscope or other data or imaging module, 8. Remote control module to enable an operator to control one or more parameters of one or more functional modules 18 , 9. Programmable Microprocessor that can store one or more operation settings for one or more functional modules 18 etc., and 10. Stabilization device for holding various apparatuses during the procedure which may include a stabilization arm, table, clip, intranasal or extranasal inflatable support or robotically controlled apparatus, 11. Rotary drive module for rotating rotatable device such as a drill or auger (e.g., a motor having a rotation drive shaft or drive cable attached thereto.
[0137] One or more functional modules 18 may be connected to the working device 10 . Instrument console module 16 can be controlled by console control means 20 , e.g. a foot pedal controller, a remote controller etc. Instrument console 16 may be fitted with wheels to enable an operator to change the position of the instrument console 16 in an operating area. In one embodiment, instrument console module 16 and C-arm fluoroscope 14 are integrated in a single unit.
[0138] FIG. 1A shows a magnified view of region 1 A of FIG. 1 showing a system for catheter-based minimally invasive sinus surgery of a human patient. In FIG. 1A , a balloon catheter is used as an example of working device 10 . Working device 10 has attachments for a variety of auxiliary devices such as a balloon inflation syringe 22 , a guidewire 24 and a suction or irrigation tube 26 . Working device 10 and the auxiliary devices may be detachably attached to treatment tray 12 . Treatment tray 12 may comprise one or more treatment tray controllers 28 to control one or more treatment parameters. Treatment tray 12 may comprise one or more storage modules to store devices used during a surgery e.g. irrigation bottles, swabs etc.
[0139] FIG. 1B shows a perspective view of a treatment tray for catheter-based minimally invasive sinus surgery of a human patient. Treatment tray 12 comprises one or more device holders 30 to detachably hold devices during the surgery. In one embodiment, device holders 30 are detachably attached to device holder slots 32 on treatment tray 12 . Thus the position of device holders 30 on treatment tray 12 can be changed by removing a device holder 30 from a device holder slot 32 and transferring to a new device holder slot 32 .
[0140] FIG. 2A shows a portion of a stabilizing device 100 comprising a stabilizing member 102 . Stabilizing member 102 comprises a lumen through which working device 10 can be introduced. In this example, stabilizing member 102 is located in a nostril. Alternatively, stabilizing member 102 may be located in other suitable regions of the head e.g. the nasal passages.
[0141] Stabilizing member 102 may be oriented to stabilizing device 100 in a variety of orientations. Also, the stabilizing member can be used to stabilize more than one working device. FIGS. 2B-2D show various alternate embodiments of stabilizing member 102 of FIG. 2A . FIG. 2B shows an embodiment of a radially symmetrical stabilizing member 104 , wherein the axis 106 of stabilizing member 104 is substantially parallel to the axis 110 of stabilizing device 100 . FIG. 2C shows an embodiment of a radially symmetrical stabilizing member 112 . The axis 114 of stabilizing member 112 is substantially non-parallel to the axis 116 of stabilizing device 100 . FIG. 2D shows an embodiment of a stabilizing member 118 , wherein stabilizing member 118 comprises two lumens enclosing a first stabilizing device 120 and a second stabilizing device 122 . Suitable materials that can be used for constructing the stabilizing members are:
Foam materials such as polyurethane foam, polyvinyl chloride foam, Thermal-Reactive Foam™ etc., Inflatable members such as compliant or non-compliant balloons, Moldable materials such as silicone rubber or wax, Metals such as stainless steel or super-elastic or shape memory metals such as Nitinol Thermoplastic elastomers such as block copolymers e.g. styrene-butadiene-styrene (SBS) rubber or ionomers etc.
[0147] The stabilizing members may be pre-molded to a predefined shape.
[0148] FIGS. 2E-2G show perspective views of various embodiments of inflatable occluding devices. FIG. 2E shows a partial view of an occluding device 124 comprising an inflatable occluding member 126 . Inflatable occluding member 126 may be made of compliant materials e.g. silicone rubber, or non-compliant materials e.g. polyethylene terephthalate (PET). Inflatable occluding member 126 can be inflated through an inflation port 127 located on the occluding device 124 . Occluding device 124 can have one or more device insertion ports. The device insertion ports can be used to insert a variety of diagnostic or therapeutic devices such as endoscopes, guidewires, catheters etc. In this example, occluding device 124 has a first device insertion port 128 and a second device insertion port 130 . The device insertion ports may comprise one or more flush ports. In this example, occluding device 124 comprises a first flush port 132 located on first device insertion port 128 and a second flush port 134 located on second device insertion port 130 . Such an occluding device may be used for occluding one or two nostrils to provide a gas-tight or liquid-tight seal against the nostril or to stabilize devices that are passed through the device insertion ports on the occluding device.
[0149] The inflatable occluding member may be made of variety of shapes. FIG. 2F shows an occluding device 136 comprising an inflatable occluding member 138 of an elongated shape wherein the diameter of the inflatable occluding member 138 tapers along the length of occluding device 136 . Inflatable occluding member 138 may also be spherical, disk shaped, cylindrical, conical etc.
[0150] The inflatable occluding member may comprise a variety of surface features. For example, FIG. 2G shows an occluding device 140 comprising an inflatable occluding member 142 . Inflatable occluding member comprises a series or parallel circular ribs on its surface. Other surface features such as coatings (e.g. friction increasing coatings, abrasion resisting coatings, puncture resisting coatings, conductive coatings, radiopaque coatings, echogenic coatings, thrombogenicity reducing coatings and drug releasing coatings etc.), braids, grooves etc. may also be present on inflatable occluding member 142 .
[0151] FIGS. 3 A- 3 D′ show embodiments of stabilizing members comprising an adhesive element. FIG. 3A shows front view of an embodiment of a stabilizing member 200 comprising a pair of upper wings 202 and a pair of lower wings 204 . In this embodiment, upper wings 202 are larger than lower wings 204 . Stabilizing member 200 further comprises one or more orifices 206 through which one or more working devices can be introduced. Stabilizing member 200 is made of a light weight, flexible material that conforms to the contours of the patient's body. Examples of such materials are woven and non-woven fabrics, plastic films (e.g. polyvinylchloride films, polypropylene films etc.), cellulose, paper etc. Stabilizing member 200 may have a porous structure for increased transmission of water vapor produced in perspiration from the skin under stabilizing member 200 . One surface of stabilizing member 200 is coated with an adhesive to enable stabilizing member 200 to adhere to a surface on a patient's body. A non-allergenic adhesive is used to minimize skin irritation. Examples of such adhesives are non-allergenic pressure-sensitive adhesives such as silicone pressure sensitive adhesives, rubber pressure sensitive adhesives and acrylic or hydrogel pressure sensitive adhesives. Stabilization member 200 may also be lubricated with a silicone or other biocompatible lubricant at the orifice to allow easier introduction and removal of devices.
[0152] Stabilizing member 200 may be used to stabilize one or more working devices. FIG. 3B shows a front view of stabilizing member 200 of FIG. 3A with two working devices: a first working device 208 and a second working device 210 . FIG. 3C shows a front view of the stabilizing member 200 of FIG. 3A with a single working device 212 .
[0153] FIG. 3D shows a side view of stabilizing member 200 of FIG. 3A attached to a patient's body. Upper wings 202 are attached on the nose of the patient. Lower wings 204 are attached above the upper lip of the patient. A working device 10 is introduced through the orifice 206 into the patient's nose. FIG. 3 D′ shows a front view of stabilizing member 200 of FIG. 3A attached to a patient's body.
[0154] FIGS. 4A and 4B show perspective views of an occluding device in deflated and inflated states respectively. Occluding device 300 comprises a shaft 302 and an inflatable balloon 304 located on distal region of shaft 302 . Shaft 302 has a diameter D.sub.1 and inflatable balloon 304 has a diameter D.sub.2 in the deflated state, wherein D.sub.2 is greater then D.sub.1. Inflatable balloon 304 can be made of compliant materials e.g. polyurethane, silicone etc. or non-compliant materials e.g. polyethylene terephthalate etc. Inflatable balloon 304 can be inflated through balloon inflation port 306 located on proximal region of occluding device 300 . The inflated diameter D.sub.3 of the inflatable balloon is greater than D.sub.2 and is particularly suitable for occluding the Nasopharynx. Occluding device 300 further comprises a series of aspiration ports 308 located proximal to inflatable balloon 304 . Aspiration ports 308 are connected to an aspiration lumen 310 to aspirate contents proximal to inflatable balloon 304 .
[0155] Any diagnostic or therapeutic device disclosed herein may comprise one or more malleable regions. For example, FIG. 5 shows a perspective view of a guide catheter comprising a plastically deformable (malleable) region. Guide catheter 400 comprises a shaft 402 comprising a malleable region 404 located on distal region of shaft 402 . Shaft 402 may comprise stiffening elements e.g. a braid, hypotube etc. Malleable region 404 may comprise malleable metallic tubes, rods (e.g. rods embedded in shaft 402 etc.), wires etc. Examples of metals that can be used for constructing malleable region 404 are malleable stainless steel, fully annealed stainless steel, copper, aluminum etc. Guide catheter 400 further comprises a threaded luer 406 located on proximal end of shaft 402 . In this example, malleable region 404 is located on distal end of guide catheter 400 . Malleable region 404 can also be located on proximal region or any other intermediate region on shaft 402 . Shaft 402 may also comprise more than one malleable regions. Such a design comprising one or more malleable regions can be used for any of the devices mentioned herein such as catheters with working elements, guide catheters, guide catheters with a pre-set shape, steerable guide catheters, steerable catheters, guidewires, guidewires with a pre-set shape, steerable guidewires, ports, introducers, sheaths or other diagnostic or therapeutic devices.
[0156] FIG. 6 shows a perspective view of a guide catheter comprising a lubricious layer. Guide catheter 500 comprises a shaft 502 comprising a threaded luer 504 located on the proximal end of the shaft 502 . FIG. 6A shows a crossectional view of the guide catheter of FIG. 6 through the plane 6 A- 6 A. Shaft 502 comprises a braid 506 embedded in the shaft. Shaft 502 further comprises a lubricious layer 508 located on the inner surface of shaft 502 . Lubricious layer 508 may be made of suitable materials such as Teflon liners, Teflon coatings or Teflon sheaths. Such a design comprising one or more lubricious layers can be used for any of the devices mentioned herein such as catheters with working elements, guide catheters, guide catheters with a pre-set shape, steerable guide catheters, steerable catheters, guidewires, guidewires with a pre-set shape, steerable guidewires, ports, introducers, sheaths or other diagnostic or therapeutic devices.
[0157] FIG. 7 shows perspective view of an embodiment of a guide catheter comprising a straight hypotube. Guide catheter 600 comprises a tubular element 602 and a hypotube 604 attached to the external surface of tubular element 602 . Suitable materials for constructing hypotube 604 are Stainless Steel 304, Nitinol etc. In one embodiment, hypotube 604 is annealed to the external surface of tubular element 602 . Tubular element 602 can be made from a variety of materials including Pebax, HDPE etc. Tubular element 602 may comprise a braid or a jacket. In an embodiment, tubular element 602 comprises a lubricious coating 605 on its inner surface. The lubricious coating 605 can be made of suitable lubricious materials such as Teflon. In an embodiment, tubular element 602 comprises a bent or angled region near the distal end of tubular element 602 . The bent or angled region may enclose an angle from 0 degrees to 180 degrees. Further this bent or angled region may be further bent out of plane to present a compound three-dimension end shape. Hypotube 604 can be malleable or substantially stiff. A malleable hypotube can be used in situations where the guide catheter 600 has to be bent or distorted to optimize its shape to conform to a patient's anatomy. Examples of materials that can be used to make a malleable hypotube are malleable stainless steel, fully annealed stainless steel, copper, aluminum etc. A substantially stiff hypotube can be used in situations where extra support is needed for introduction or removal or devices through guide catheter 600 . Examples of materials that can be used to make a substantially stiff hypotube are Stainless Steel 304, Nitinol etc. Hypotube 604 may be bent to a two-dimensional or three-dimensional shape. Distal tip of tubular element 602 may comprise a radio-opaque marker 606 e.g. a standard radio-opaque marker band. The proximal region of tubular element 602 comprises a threaded luer.
[0158] FIG. 7A shows a crossectional view of guide catheter 600 of FIG. 7 through plane 7 A- 7 A. The crossection of guide catheter 600 shows an outer hypotube 604 enclosing a tubular member 602 which in turn comprises a lubricious coating 605 located on the inner surface of tubular member 602 .
[0159] FIG. 8 shows a perspective view of a second embodiment of a guide catheter comprising a straight hypotube. Guide catheter 700 comprises a hypotube 702 . Proximal end of hypotube 702 may comprise a threaded luer 704 . Hypotube 702 encloses a tubular liner 706 that protrudes from the distal end of hypotube 702 . Suitable materials for constructing tubular liner 706 are PTFE, Nylon, PEEK etc. Distal region of tubular liner 706 is covered with a tubular element 708 . Tubular element 708 may be constructed of suitable materials such as Pebax, HDPE, Nylon etc. and may comprise a braid. Proximal end of tubular element 708 may be bonded to distal end of hypotube 702 or may overlap distal region of hypotube 702 . In one embodiment, distal region of tubular element 708 comprises a bent or angled region. In another embodiment, stiffness of tubular element 708 varies along the length of tubular element 708 . Tubular element 708 may comprise a radio-opaque marker band 710 near distal end of tubular element 708 . FIG. 8A shows a crossectional view of guide catheter 700 of FIG. 8 through plane 8 A- 8 A showing hypotube 702 and tubular liner 706 . FIG. 8B shows a crossectional view of guide catheter 700 of FIG. 8 through plane 8 B- 8 B showing tubular element 708 and tubular liner 706 .
[0160] The hypotubes disclosed above may be malleable or non-malleable. They may also comprise one or more bent or angled regions. For example, FIG. 8C shows a perspective view of an embodiment of a guide catheter comprising a curved or bent hypotube to facilitate access to the frontal sinuses. Guide catheter 712 comprises a hypotube 714 comprising a threaded luer 716 at the proximal end of hypotube 714 . Hypotube 714 may comprise one or more bent or angled regions. In this embodiment, the bent or angled region encloses an angle ranging from 60 degrees to 180 degrees. Hypotube 714 may be malleable or non-malleable. In this example, hypotube 714 encloses a tubular element 718 . Tubular element 718 may be constructed of suitable materials such as Pebax, HDPE etc. The distal region of tubular element 718 comprises a bent or angled region. In this embodiment, the bent or angled region encloses an angle ranging from 60 degrees to 170 degrees to facilitate access to the frontal sinuses using guide catheter 712 . Distal region of tubular element 718 may comprise a radio-opaque marker 720 .
[0161] FIG. 8D shows a perspective view of a second embodiment of a guide catheter comprising a curved or bent hypotube to facilitate access to the sphenoid sinuses. The catheter construction is similar to the catheter in FIG. 8C except the bent or angled region of hypotube 714 encloses an angle ranging from 90 degrees to 180 degrees and the bent or angled region of tubular element 718 encloses an angle ranging from 120 degrees to 180 degrees.
[0162] FIG. 8E shows a perspective view of an embodiment of a guide catheter comprising two bent or angled or curved regions to facilitate access to the maxillary sinuses. Guide catheter 740 comprises a tubular element 742 comprising a threaded luer 744 at the proximal end of tubular element 742 . Tubular element 742 further comprises a proximal bent, curved or angled region 746 enclosing an angle ranging from 90 degrees to 180 degrees and a distal bent, curved or angled region 748 enclosing an angle ranging from 90 degrees to 180 degrees. Tubular element 742 can be constructed from a variety of biocompatible materials such as Pebax, HDPE, Nylon, PEEK etc. and may comprise a braid. The inner surface of tubular element 742 may comprise a lubricious layer e.g. a Teflon layer. A curved region 750 is attached to the distal end of tubular element 742 . Curved region 750 may enclose an angle ranging from 75 degrees to 180 degrees. The stiffness of curved region 750 is more than the stiffness of tubular element 742 so that there is no significant change to the shape of curved region 750 during the operation of guide catheter 740 . The distal end of curved region 750 comprises a soft, atraumatic tip 752 . The distal end of curved region 750 may also comprise a radioopaque marker. Guide catheter 740 may be further bent out of plane to present a compound three-dimension end shape. FIG. 8F shows a perspective view of a second embodiment of a guide catheter comprising two bent or angled or curved regions and a hypotube to facilitate access to the maxillary sinuses. The construction of guide catheter 754 is similar to guide catheter 740 in FIG. 8E except that guide catheter 754 further comprises a hypotube 756 on the outer surface of the proximal region of guide catheter 754 .
[0163] FIG. 8G shows a coronal section of the paranasal anatomy showing a method of accessing a maxillary sinus ostium using guide catheter 754 of FIG. 8F . Guide catheter 754 is introduced through a nostril and advanced in the paranasal anatomy such that atraumatic tip 752 is located inside or adjacent to a maxillary sinus ostium MSO. Proximal bent, curved or angled region 746 allows guide catheter 754 to be positioned around the inferior turbinate IT. Similarly, distal bent, curved or angled region 748 allows guide catheter 754 to be positioned around the middle turbinate MT. A guidewire or a suitable diagnostic or therapeutic device may then be introduced through the lumen of guide catheter 754 into the maxillary sinus MS. FIG. 8H shows a sagittal section of the paranasal anatomy showing the method of FIG. 8G to access a maxillary sinus ostium using guide catheter 754 of FIG. 8F .
[0164] FIG. 8I shows a perspective view of an example of a guide catheter comprising a common proximal portion and a plurality of detachable distal tips. Distal end of common proximal portion 760 attaches to proximal end of a first detachable tip 762 by an attachment mechanism. First detachable tip 762 comprises an angled, curved or bent region enclosing an angle of 80-110 degrees suitable for access to the frontal and ethmoid sinuses. Similarly, distal end of common proximal portion 760 attaches to proximal end of a second detachable tip 764 by an attachment mechanism. Second detachable tip comprises two angled, curved or bent regions enclosing angles of 80-110 degrees and 80-110 degrees respectively. Such a design is suitable for access to the maxillary sinuses. Examples of attachment mechanisms are screw mechanisms, snap fitting mechanisms, slide fit mechanisms etc. Distal end of first detachable tip 762 and second detachable tip 764 may comprise a radioopaque marker such as a radioopaque band. Such a design comprising detachable distal regions can be used in a variety of diagnostic or therapeutic devices discloses herein. It can be used for easy access to one or more anatomical regions in the ear, nose, throat or mouth by using multiple detachable distal tips, wherein each detachable tip is optimized for access to a particular anatomical region.
[0165] FIG. 9 shows a perspective view of a set of devices to dilate or modify ostia or other openings in the ear, nose, throat or mouth structures. Guide catheter 800 comprises a shaft 802 comprising a threaded luer 804 at proximal end of shaft 802 . Distal end of shaft 802 comprises a radio-opaque marker band MB to enable the physician to identify the tip of shaft 802 in a fluoroscopic image. The distal end of shaft 802 may be substantially straight or may comprise one or more bent or angled regions. One or more distance markings DM may also be located on the shaft 802 . An optional subselective catheter 806 may also be present in the set of devices. Subselective catheter 806 comprises a shaft 808 comprising a threaded luer 810 at the proximal end of shaft 808 . Inner diameter of shaft 808 is smaller than inner diameter of shaft 802 . Distal end of the shaft 808 comprises a radio-opaque marker band MB to enable the physician to identify the tip of shaft 808 in a fluoroscopic image. Distal end of shaft 808 may be substantially straight or may comprise one or more bent or angled regions. One or more distance markings DM may also be located on the shaft 808 . Working device 812 comprises a shaft 814 comprising a working element 816 located on distal region of shaft 814 and a threaded luer 818 located on proximal end of shaft 814 . In this example, the working element 816 is a dilating balloon. Other examples of working elements include dilating stents, suction or irrigation devices, needles, polypectomy tools, brushes, brushes, energy emitting devices such as ablation devices, laser devices, image-guided devices containing sensors or transmitters, endoscopes, tissue modifying devices such as cutters, biopsy devices, devices for injecting diagnostic or therapeutic agents, drug delivery devices such as substance eluting devices, substance delivery implants etc. The distal end of shaft 814 may be substantially straight or may comprise a bent or angled region. One or more distance markings DM may also be located on shaft 814 . The set of devices further comprises a guidewire 820 . Guidewire 820 may be substantially straight or may comprise a bent or angled region. One or more distance markings DM may also be located on guidewire 820 . In one embodiment of a method using the abovementioned set of devices, guide catheter 800 is introduced into a patient's body so that distal end of guide catheter 800 is in the vicinity of an anatomical opening (e.g. an ostium) of an anatomical region (e.g. a paranasal sinus). Thereafter, guidewire 820 is introduced through guide catheter 800 into the anatomical region e.g. the paranasal sinus. If necessary, guide catheter 800 may be removed and the smaller subselective catheter 806 may be introduced over guide wire 820 into the paranasal sinus. Thereafter, working device 812 is introduced over guidewire 820 into the paranasal sinus and a diagnostic or therapeutic procedure is performed by working device 812 . In another embodiment of a method using the abovementioned set of devices, subselective catheter 806 is introduced into a patient's body so that distal end of subselective catheter 806 is in the vicinity of an anatomical opening (e.g. an ostium) of an anatomical region (e.g. a paranasal sinus). Thereafter, guidewire 820 is introduced through subselective catheter 806 into the anatomical region e.g. the paranasal sinus. Thereafter, subselective catheter 806 is removed. Larger guide catheter 800 is then introduced over guide wire 820 . Working device 812 is then introduced over guidewire 820 into the paranasal sinus and a diagnostic or therapeutic procedure is performed by working device 812 . This method embodiment enables a user to introduce larger working device 812 in the anatomical region.
[0166] FIG. 10 shows a perspective view of a probing device. The probing device 900 comprises a probing element 902 and a detachable handle 904 . Probing element 902 comprises an atraumatic tip 906 located on the distal end of probing element 902 . In one embodiment, atraumatic tip 906 is spherical. Probing element 902 can be made from a variety of biocompatible materials such as metals (e.g. stainless steel, titanium, Nitinol etc.) or polymers (e.g. Pebax, polyethylene etc.). Probing element 902 may be rigid or flexible or malleable. In the embodiment shown in FIG. 10 , the distal region of the probing element 902 is malleable. This enables a physician to adjust probing device 900 for a patient's unique anatomy. Probing element 902 may comprise one or more curved or angled regions. Length of probing element 902 can range from 10 centimeters to 30 centimeters. Detachable handle can be attached to the probing element 902 by a variety of attachment mechanisms including screw arrangement, clipping mechanism etc. The tip of the probing element may further be modified to include a marker, sensor or transmitter capable of being tracked using one or more imaging modalities, such as x-ray, electromagnetic, radio-frequency, ultrasound, radiation, optics, and/or similar modalities.
[0167] FIGS. 10A-10C show various steps of a method of using the probing device shown in FIG. 10 to access an anatomical region. In FIG. 10A , probing device 900 is advanced in to a patient's frontal sinus ostium through the nasal cavity. Atraumatic tip 906 prevents the probing device 900 from perforating and damaging healthy tissues. Thereafter, in FIG. 10B , detachable handle 904 is detached from probing element 902 . Thereafter, in FIG. 10C , a working device 908 e.g. a catheter is advanced over the probing element 902 into the patient's frontal sinus ostium. Working device 908 can then be used to perform a diagnostic or therapeutic procedure or introduce other devices. In this example, probing device 900 was used to access the patient's frontal sinus ostium. Other anatomical locations in the patient's body e.g. ostia of other paranasal sinuses, ostia of lachrymal ducts, regions in the Eustachian tube, ducts of salvary glands, etc. may be accessed by similar methods. It is also possible that working device 908 may be preloaded over probing element 902 and maintained in a retracted position relative to the probing element until distal portion of the probing element 902 is introduced into a desired location. Further, multiple working devices may be inserted within working device 908 or over working device 908 once it is properly positioned.
[0168] FIG. 11A shows a perspective view of a first embodiment of a dual balloon catheter that can be used to perform a diagnostic or therapeutic procedure. Catheter 1000 comprises a catheter shaft 1002 and a proximal balloon 1004 and a distal balloon 1006 located on catheter shaft 1002 . A variety of diagnostic or therapeutic modules may be located in the inter-balloon region 1008 located between proximal balloon 1004 and distal balloon 1006 . Examples of such diagnostic or therapeutic modules are dilating or occluding balloons, dilating stents, suction or irrigation devices, needles, polypectomy tools, energy emitting devices like ablation devices, laser devices, image-guided devices containing sensors or transmitters, imaging devices, endoscopes, tissue modifying devices like cutters, biopsy devices, devices for injecting diagnostic or therapeutic agents, lavage devices, drug delivery devices such as substance eluting devices, substance delivery implants etc. etc. A catheter hub 1010 is located on the proximal end of catheter shaft 1002 . Catheter hub 1010 comprises a balloon inflation port 1012 that can be used to inflate both proximal balloon 1004 and distal balloon 1006 .
[0169] FIG. 11B shows a perspective view of a second embodiment of a dual balloon catheter that can be used to perform a diagnostic or therapeutic procedure. The catheter 1014 shown in this embodiment further comprises a second balloon inflation port 1016 . Balloon inflation port 1012 is used to inflate proximal balloon 1004 and second balloon inflation port 1016 is used to inflate distal balloon 1006 . In one embodiment of a method using catheter 1014 , distal balloon 1006 is inflated before proximal balloon 1004 .
[0170] FIGS. 11C-11E show perspective views of third, fourth and fifth embodiments respectively of dual balloon catheters for dilating an anatomical region. In FIG. 11C , catheter 1020 comprises a catheter shaft 1022 comprising a catheter hub 1024 at the proximal end of catheter shaft 1022 . The distal region of catheter shaft 1022 comprises a proximal balloon 1026 and a distal balloon 1028 . Proximal balloon 1026 and distal balloon 1028 can be made from compliant or non-compliant materials. Catheter shaft 1022 further comprises a dilating balloon 1030 located between proximal balloon 1026 and distal balloon 1028 . Dilating balloon 1030 is constructed from suitable non-compliant materials such as Polyethylene terephthalate etc. The balloons are inflated through three balloon inflation ports located on catheter hub 1024 . A first balloon inflation port 1032 is used to inflate proximal balloon 1026 , a second balloon inflation port 1034 is used to inflate distal balloon 1028 and a third balloon inflation port 1036 is used to inflate dilating balloon 1030 . FIG. 11D shows a perspective view of catheter 1020 in FIG. 11C further comprising a stent 1038 disposed on dilating balloon 1030 . Several types of stent designs can be used to construct stent 1038 such as metallic tube designs, polymeric tube designs, chain-linked designs, spiral designs, rolled sheet designs, single wire designs etc. These designs may have an open celled or closed celled structure. A variety of fabrication methods can be used for fabricating stent 1038 including but not limited to laser cutting a metal or polymer element, welding metal elements etc. A variety of materials can be used for fabricating stent 1038 including but not limited to metals, polymers, foam type materials, plastically deformable materials, super elastic materials etc. Some non-limiting examples of materials that can be used to construct stent 1038 are Nitinol, stainless steel, titanium, polyurethane, gelfilm, polyethylene and silicones e.g. silastic. A variety of features can be added to stent 1038 including but not limited to radiopaque coatings, drug elution mechanisms etc. FIG. 11E shows a perspective view of catheter 1020 in FIG. 11C wherein proximal balloon 1026 and distal balloon 1028 are conical. Dual balloon catheters may also be used to deploy self-expanding stents at a target anatomical region.
[0171] FIGS. 11F-11J show the various steps of a method of dilating an anatomical region using the catheter of FIG. 11D . In FIG. 11F , catheter 1020 is introduced into an anatomical region to be dilated. In one embodiment, catheter 1020 is introduced over a guidewire 1040 . In FIG. 11G , distal balloon 1028 is inflated through second balloon inflation port 1034 . Thereafter, catheter 1020 is pulled in the proximal direction till distal balloon 1028 gets lodged in the anatomical region to be dilated. Thereafter in FIG. 11H , proximal balloon 1026 is inflated through first balloon inflation port 1032 . This enables catheter 1020 to be securely lodged in the anatomical region to be dilated. Thereafter in FIG. 11I , dilating balloon 1030 is inflated through third balloon inflation port 1036 . Inflated dilation balloon 1030 exerts an outward force on the anatomical region and causes it to dilate. This step also deploys stent 1038 . Thereafter in FIG. 11J , proximal balloon 1026 , distal balloon 1028 and dilating balloon 1030 are deflated and catheter 1020 is removed by pulling catheter 1020 in the proximal direction.
[0172] FIGS. 12A-12C show the various steps of a method of deploying a stent in the ear, nose, throat or mouth using a working catheter comprising a locating mechanism. In this example, the locating mechanism is a locator balloon. A working device 1100 is provided that comprises a locator balloon 1104 and a stent 1106 located on a stent deploying balloon 1108 located on a catheter shaft 1110 . Locator balloon 1104 is located on the distal region of the catheter shaft 1110 and stent 1106 is located proximal to the locator balloon 1104 . In FIG. 12A , the working device 1100 is inserted into an anatomical region through an anatomical opening 1111 such that the locator balloon 1104 is located distal to anatomical opening 1111 . Examples of the anatomical region are paranasal sinuses, Eustachian tubes, lachrymal ducts and other structures in the ear, nose, throat or mouth etc. Examples of anatomical opening 1111 are ostia of paranasal sinuses, ostia of lachrymal ducts etc. In FIG. 12B , locator balloon 1104 is inflated. The inflated diameter of the locater balloon is greater than the diameter of the anatomical opening.
[0173] Working device 1100 is then pulled in the proximal direction such that locator balloon 1104 presses against the anatomical opening 1111 . This enables stent 1106 to be positioned accurately in a desired location relative to anatomical opening 1111 . In FIG. 12C , stent deploying balloon 1108 is inflated to deploy stent 1106 . Thereafter, stent deploying balloon 1108 and locator balloon 1104 are deflated and the working device 1100 is removed by pulling it out in the proximal direction. Similar working catheters comprising locating mechanisms can also be used to deploy self-expanding stents.
[0174] In this example, the locating mechanism was a locator balloon. Other examples of locating device are deployable elements such as wire meshes, radially projecting wires, deployable devices located on guidewires (e.g. balloons, wire meshes etc.), devices deployed on pull-elements (e.g. radially expandable elements etc.) etc.
[0175] FIGS. 12D-12H show the various steps of a method of dilating an anatomical opening in the ear, nose, throat or mouth using a combination of a dilating device and an anchoring device. In this example, the dilating device is a dilating balloon catheter and the anchoring device is an anchoring balloon catheter. In FIG. 12D , an anchoring balloon catheter 1120 comprising a catheter shaft 1122 and an anchoring balloon 1124 is inserted over a guidewire GW into an anatomical opening. In one embodiment, shaft 1122 of anchoring balloon catheter 1120 is coated with a lubricious coating such as Teflon. In this example the anatomical opening is the sphenoid sinus ostium SSO of a sphenoid sinus SS. In FIG. 12E , anchoring balloon 1124 is inflated. The inflated diameter of anchoring balloon 1124 is greater than the diameter of the anatomical opening. Thereafter, anchoring balloon catheter 1120 is pulled in the proximal direction so that anchoring balloon 1124 is anchored in the anatomical opening. In FIG. 12F , a dilating balloon catheter 1126 comprising a shaft 1128 and a dilating balloon 1130 is advanced in the proximal direction over shaft 1122 of anchoring balloon catheter 1120 . Dilating balloon catheter 1126 is advanced till the distal portion of dilating balloon catheter 1126 touches anchoring balloon 1124 . This design accurately positions dilating balloon 1130 in a target location in the anatomical opening. Thereafter, in FIG. 12G , dilating balloon 1130 is inflated to dilate the anatomical opening. Thereafter, in FIG. 12H , the dilating balloon 1130 and anchoring balloon 1124 are deflated and dilating balloon catheter 1126 and anchoring balloon catheter 1120 are withdrawn from the anatomical opening by pulling them in the proximal direction. Dilating balloon 1130 can be made of suitable non-compliant materials e.g. polyethylene terephthalate etc. Anchoring balloon 1124 can be made of suitable compliant materials e.g. polyurethane, silicone etc. or non-compliant materials e.g. polyethylene terephthalate etc. Examples of anchoring devices are catheters comprising balloons, deployable elements such as wire meshes, radially projecting wires; deployable devices located on guidewires (e.g. balloons, wire meshes etc.); devices deployed on pull-elements (e.g. radially expandable elements etc.) etc.
[0176] Such a combination of an anchoring device and a working device inserted along the anchoring device can be used for a variety of other methods and devices disclosed herein for treating anatomical openings such as ostia of paranasal sinuses, ostia of lachrymal ducts, ducts of salvary glands, Eustachian tubes and other ear, nose, throat or mouth structures etc.
[0177] FIG. 13 shows a perspective view of a dilating device comprising an electrode element to reduce restenosis. Dilating device 1200 comprises a shaft 1202 and a dilating element 1204 located on the distal region of shaft 1202 . Examples of dilating elements are non-compliant dilating balloons, mechanically expandable elements etc. Dilating device 1200 further comprises an electrode element 1206 located on dilating element 1204 . Electrode element 1206 in combination with one or more surface electrodes attached to a surface of a patient's body delivers electrical energy to an anatomical region to be dilated. The electrical energy causes a controlled destruction of the adjacent anatomical region thereby reducing the risk to restenosis of the dilated region. Electrode element 1206 may have a variety of configurations including meshes, wires wound in a spiral configuration, wires wound in a sinusoidal configuration etc. Electrode element 1206 can be constructed from a variety of biocompatible metallic materials such as platinum-iridium alloys (e.g. 90% platinum/10% iridium) etc. Dilating device 1200 may further comprise an insulating layer between electrode element 1206 and dilating element 1204 . In one embodiment, electrode element 1206 is located on a sheath that can be advanced over dilating device 1200 such that electrode element 1206 is located above dilating element 1204 .
[0178] FIG. 14 shows a perspective view of an embodiment of a balloon catheter comprising a sizing balloon and a dilating balloon. A portion of the sizing balloon has been removed to show the dilating balloon underneath the sizing balloon. Balloon catheter 1300 comprises a shaft 1302 and a dilating balloon 1304 located on distal region of shaft 1302 . Dilating balloon 1304 can be made of suitable non-compliant materials e.g. polyethylene terephthalate, Nylon etc. Dilating balloon 1304 is inflated through a first balloon inflation opening 1305 . Balloon catheter 1300 further comprises a sizing balloon 1306 located around dilating balloon 1304 . Sizing balloon 1306 is made from a compliant or semi-compliant material such as crosslinked polyethylene or other polyolefins, polyurethane, flexible polyvinylchloride, Nylon etc. Sizing balloon 1306 is inflated through a second balloon inflation opening 1307 . Dilating balloon 1304 and sizing balloon 1306 enclose an inter-balloon volume 1308 . FIG. 14A shows a crossection of the balloon catheter in FIG. 14 through plane 14 A- 14 A. Shaft 1302 comprises a guidewire lumen 1310 , a first inflation lumen 1312 that terminates distally in first balloon inflation opening 1305 of FIG. 14 , and a second inflation lumen 1314 that terminates distally in second balloon inflation opening 1307 of FIG. 14 .
[0179] FIGS. 14B-14D show the various steps of dilating an anatomical opening using the balloon catheter in FIG. 14 . In FIG. 14B , balloon catheter 1300 is introduced over a guidewire GW into an anatomical opening 1316 to be dilated. Examples of the types of anatomical openings 1316 that may be dilated by this invention include ostia of paranasal sinuses, Eustachian tubes, ostia of lachrymal ducts, etc. Thereafter, in FIG. 14C , sizing balloon 1306 is inflated using an imageable inflating medium. Examples of suitable imageable inflating media are saline with a radioopaque contrast agent, carbon dioxide gas etc. Distal region of balloon catheter 1300 is subsequently imaged using a suitable imaging modality such as fluoroscopy or X-rays. This enables an operator to accurately estimate the size of anatomical opening 1316 . Such a balloon catheter is also suited for estimating the diameter of the narrowest region in a tubular anatomical region e.g. a Eustachian tube prior to performing a diagnostic or therapeutic procedure such as balloon dilation. On the basis of information obtained during step 14 C, balloon catheter 1300 may be repositioned and step 14 C repeated if necessary. Thereafter, in step 14 D, sizing balloon 1306 is deflated. Also in step 14 D, dilating balloon 1304 is inflated to dilate a target region in anatomical opening 1316 . Thereafter, dilating balloon 1304 is deflated and balloon catheter 1300 is withdrawn from anatomical opening 1316 . In one embodiment, sizing balloon 1306 may be reinflated after a balloon dilation procedure to obtain feedback about the performance of the balloon dilation procedure.
[0180] FIG. 15 shows a perspective view of a balloon catheter 1400 for delivering diagnostic or therapeutic agents. This balloon catheter 1400 comprises a catheter shaft 1402 which may be flexible, malleable or rigid, and a dilating balloon 1404 located on the distal region of shaft 1402 . Dilating balloon 1404 can be made of any suitable compliant or non-compliant materials (e.g. polyethylene terephthalate etc.). An outer balloon or sheath 1406 covers the dilating balloon 1404 , as shown in the cut-away view of FIG. 15 . Sheath 1406 can be made of suitable non-compliant materials e.g. polyethylene terephthalate etc. or compliant or semi-compliant materials such as crosslinked polyethylene or other polyolefins, polyurethane, flexible polyvinylchloride, Nylon etc. Sheath 1406 comprises one or more pores 1408 through which diagnostic or therapeutic agents can be delivered to the surrounding anatomy. Pores 1408 may have a pore size ranging from sub-micron to a few microns. Dilating balloon 1404 is inflated by a balloon inflation lumen 1410 . The diagnostic or therapeutic agents can be delivered to the region between sheath 1406 and dilating balloon 1404 by an agent delivery lumen 1412 . In this particular embodiment, sheath 1406 is attached to shaft 1402 . FIG. 15A shows a crossection through the plane 15 A- 15 A of FIG. 15 showing shaft 1402 comprising balloon inflation lumen 1410 , agent delivery lumen 1412 and a guidewire lumen 1414 .
[0181] FIG. 16 shows a perspective view of a balloon catheter comprising one or more agent delivery reservoirs. Balloon catheter 1500 comprises a shaft 1502 and a balloon 1504 located on the distal region of shaft 1502 . Balloon 1504 may be made from suitable compliant or semi-compliant material such as crosslinked polyethylene or other polyolefins, polyurethane, flexible polyvinylchloride, Nylon, etc., or from non-compliant materials such as polyurethane, etc. Balloon catheter 1500 further comprises one or more agent delivery reservoirs 1506 located on balloon 1504 . Agent delivery reservoirs 1506 contain one or more diagnostic or therapeutic agents absorbed in a matrix. Examples of diagnostic or therapeutic agents are contrast agents, pharmaceutically acceptable salt or dosage form of an antimicrobial agent (e.g., antibiotic, antiviral, anti-parasitic, antifungal, etc.), a corticosteroid or other anti-inflammatory (e.g., an NSAID), a decongestant (e.g., vasoconstrictor), a mucous thinning agent (e.g., an expectorant or mucolytic), an anesthetic agent with or without vasoconstrictor (e.g., Xylocalne with or without epinephrine, Tetracaine with or without epinephrine), an analgesic agent, an agent that prevents of modifies an allergic response (e.g., an antihistamine, cytokine inhibitor, leucotriene inhibitor, IgE inhibitor, immunomodulator), an allergen or another substance that causes secretion of mucous by tissues, anti-proliferative agents, hemostatic agents to stop bleeding, cytotoxic agents e.g. alcohol, biological agents such as protein molecules, stem cells, genes or gene therapy preparations etc. When balloon 1504 is inflated to dilate an anatomical region, it exerts pressure on agent delivery reservoirs 1506 . This pressure squeezes out the one or more diagnostic or therapeutic agents absorbed in the matrix and causes them to be released into the anatomical region. In one embodiment, agent delivery reservoirs 1506 comprise diagnostic or therapeutic agents absorbed in a porous matrix formed of a porous material such as a flexible or rigid polymer foam, cotton wadding, gauze, etc. Examples of biodegradable polymers that may be foamed or otherwise rendered porous include polyglycolide, poly-L-lactide, poly-D-Iactide, poly(amino acids), polydioxanone, polycaprolactone, polygluconate, polylactic acid-polyethylene oxide copolymers, modified cellulose, collagen, polyorthoesters, polyhydroxybutyrate, polyanhydride, polyphosphoester, poly(alpha-hydroxy acid) and combinations thereof. Examples of non-biodegradable polymers that may be foamed or otherwise rendered porous include polyurethane, polycarbonate, silicone elastomers etc. FIG. 16A shows a crossection view through plane 16 A- 16 A of FIG. 16 showing shaft 1502 comprising a balloon inflation lumen 1508 and a guidewire lumen 1510 .
[0182] FIG. 17 shows a perspective view of a balloon catheter comprising a balloon comprising one or more micropores or openings. Balloon catheter 1600 comprises a shaft 1602 comprising a dilating balloon 1604 located on the distal region of shaft 1602 . Dilating balloon 1604 can be made of suitable non-compliant materials e.g. polyethylene terephthalate etc. Dilating balloon 1604 comprises one or more micropores 1606 of a pore size ranging from submicron (e.g. 0.5 micron) to a few microns. Micropores 1606 can be formed on material of dilating balloon 1604 by various processes including mechanical punching, mechanical drilling, irradiation e.g. directing a laser beam or an ion or electron beam at the balloon material etc. Dilating balloon 1604 is inflated using an inflating medium comprising one or more diagnostic or therapeutic agents to be delivered to a target anatomical region such as ostia of paranasal sinuses, ostia of lachrymal ducts, ducts of salvary glands, Eustachian tubes etc. Examples of diagnostic or therapeutic agents are contrast agents, pharmaceutically acceptable salt or dosage form of an antimicrobial agent (e.g., antibiotic, antiviral, anti-parasitic, antifungal, etc.), an anesthetic agent, an analgesic agent, a corticosteroid or other anti-inflammatory (e.g., an NSAID), a decongestant (e.g., vasoconstrictor), a mucous thinning agent (e.g., an expectorant or mucolytic), an agent that prevents of modifies an allergic response (e.g., an antihistamine, cytokine inhibitor, leucotriene inhibitor, IgE inhibitor, immunomodulator), an allergen or another substance that causes secretion of mucous by tissues, anti-proliferative agents, hemostatic agents to stop bleeding, cytotoxic agents e.g. alcohol, biological agents such as protein molecules, stem cells, genes or gene therapy preparations etc. When dilating balloon 1604 is inflated, a portion of the inflating medium seeps out of dilating balloon 1604 through micropores 1606 and thus is delivered to the adjacent anatomical regions. Thus dilation and agent delivery can be achieved in a single step. FIG. 17A shows a crossectional view through the plane 17 A- 17 A of FIG. 17 showing shaft 1602 comprising a guidewire lumen 1608 and a balloon inflation lumen 1610 .
[0183] FIG. 18 shows a balloon catheter comprising a balloon having an outer coating of diagnostic or therapeutic agents. Balloon catheter 1700 comprises a shaft 1702 and a dilating balloon 1704 located on the distal region of shaft 1702 . Dilating balloon 1704 can be made of suitable non-compliant materials e.g. polyethylene terephthalate etc. Dilating balloon 1704 comprises a coating 1706 of one or more diagnostic or therapeutic agents on the outer surface of dilating balloon 1704 . Coating 1706 may comprise diagnostic or therapeutic agents located in a suitable carrier medium. In one embodiment, the carrier medium is a hydrogel. In another embodiment, the carrier medium is a solid having the consistency of wax e.g. sterile bone wax.
[0184] In another embodiment, the carrier containing the agents can be deposited on the outer surface of dilating balloon 1704 just before balloon catheter 1700 is used for performing a diagnostic or therapeutic procedure. Coating 1706 may be present on the surface of dilating balloon 1704 in a variety of configurations. In one embodiment, coating 1706 is in the form of parallel strips of a carrier medium comprising one or more diagnostic or therapeutic agents. The coating may also be in the form of an annular layer, a plurality of discrete spots etc. When dilating balloon 1704 is inflated to dilate an anatomical region, coating 1706 comes into contact with the adjacent anatomical region. A portion of coating 1706 is deposited on the adjacent anatomical region which delivers the diagnostic or therapeutic agents to the adjacent anatomical region. Thus dilation and agent delivery can be achieved in a single step. In one embodiment, coating 1706 comprises a hemostatic material with a consistency of bone-wax.
[0185] FIGS. 18A-18C show the steps of a method of using the balloon catheter of FIG. 18 to dilate an anatomical region. In FIG. 18A , balloon catheter 1700 is introduced in an anatomical region 1708 . Balloon catheter 1700 is positioned such dilating balloon 1704 is located in the target region to be dilated. Thereafter, in FIG. 18B , dilating balloon 1704 is inflated. This dilates anatomical region 1708 and deposits a portion of coating 1706 on the dilated region. Thereafter, in FIG. 18C , dilating balloon 1704 is deflated and balloon catheter 1700 is withdrawn from anatomical region 1708 leaving behind a deposited layer 1710 of coating 1706 on the dilated anatomical region 1708 .
[0186] FIG. 19A shows a perspective view of a lavage catheter. Lavage catheter 1800 comprises a shaft 1802 and an occluding balloon 1804 located on the distal region of shaft 1802 . Occluding balloon 1804 can be made of suitable compliant materials e.g. polyurethane, silicone etc. or non-compliant materials e.g. polyethylene terephthalate etc. Lavage catheter 1800 further comprises a flushing tip 1806 and an aspiration tip 1808 located on the distal end of shaft 1802 . In FIG. 19A , lavage catheter 1800 is introduced over a guidewire GW into an anatomical region e.g. a sphenoid sinus SS through an anatomical opening e.g. a sphenoid sinus ostium SSO. FIG. 19B shows a crossectional view through the plane 19 B- 19 B of FIG. 19A . Shaft 1802 comprises an aspiration lumen 1810 , a flushing lumen 1812 and a guidewire lumen 1814 . Distal end of aspiration lumen 1810 opens at the distal end of aspiration tip 1808 and distal end of flushing lumen 1812 opens at the distal end of flushing tip 1806 .
[0187] FIG. 19C shows the method of operation of lavage catheter 1800 of FIG. 19A to lavage an anatomical region. In FIG. 19C , occluding balloon 1804 is inflated and lavage catheter 1800 is pulled in the proximal direction till occluding balloon occludes the anatomical opening e.g. sphenoid sinus ostium SSO. Thereafter, a flushing medium introduced in the anatomical region through flushing tip 1806 . The flushing medium may be introduced in lavage catheter 1800 from a flushing medium container 1816 e.g. a saline bag connected to the proximal region of lavage catheter 1800 . The flushing medium is aspirated from the anatomical region through aspiration tip 1808 . The proximal end of lavage catheter 1800 may be connected to a collection vessel 1818 to collect the aspirated flushing medium. In one embodiment, collection vessel 1818 is further connected to wall suction.
[0188] FIG. 20A shows a perspective view of the distal end of a second embodiment of a lavage catheter. Lavage catheter 1900 comprises a tubular member 1902 comprising a one or more openings 1904 located on the distal region of tubular member 1902 . Tubular member 1902 may be made from a variety of materials such as silicone elastomers, Pebax, HDPE etc. Distal region of tubular member 1902 may comprise a curved or bent region. Tubular member 1902 comprises a first lumen connected to openings 1904 . Suitable diagnostic or therapeutic fluids can be introduced or removed through openings 1904 . Examples of such fluids are saline, pharmaceutically acceptable salt or dosage form of an antimicrobial agent (e.g., antibiotic, antiviral, anti-parasitic, antifungal, etc.), a corticosteroid or other anti-inflammatory (e.g., an NSAID), a decongestant (e.g., vasoconstrictor), a mucous thinning agent (e.g., an expectorant or mucolytic), an agent that prevents of modifies an allergic response (e.g., an antihistamine, cytokine inhibitor, leucotriene inhibitor, IgE inhibitor, immunomodulator), an allergen or another substance that causes secretion of mucous by tissues, a contrast agent, an anesthetic agent with or without vasoconstrictor (e.g., Xylocalne with or without epinephrine, Tetracaine with or without epinephrine), an analgesic agent, hemostatic agents to stop bleeding, anti-proliferative agents, cytotoxic agents e.g. alcohol, biological agents such as protein molecules, stem cells, genes or gene therapy preparations etc. In one embodiment, tubular member 1902 comprises a second lumen that acts as a guidewire lumen.
[0189] FIG. 20B shows a perspective view of the distal end of the lavage catheter of FIG. 20A introduced in an anatomical region. In this example, the anatomical region is a maxillary sinus MS comprising a maxillary sinus ostium MSO. Lavage catheter 1900 may be introduced into the anatomical region by an over-the-wire method, through a cannula, or by a variety of methods disclosed in this patent application and in the patents documents incorporated herein by reference. Other examples of anatomical regions that can be treated using lavage catheter 1900 are other paranasal sinuses, lachrymal ducts, Eustachian tubes, and other hollow organs in the ear, nose, throat or mouth.
[0190] FIG. 20C shows an embodiment of the lavage catheter of FIG. 20A being used to lavage an anatomical region. In this embodiment, lavage catheter 1900 further comprises an outer sheath 1910 comprising an occluding balloon 1912 located on the distal region of outer sheath 1910 . Occluding balloon 1912 may be made from suitable compliant or semi-compliant material such as crosslinked polyethylene or other polyolefins, polyurethane, flexible polyvinylchloride, Nylon etc. or from non-compliant materials such as polyurethane etc. Outer sheath 1910 covers tubular member 1902 such that outer sheath and tubular member 1902 enclose a suction lumen 1914 between them. Tubular member 1902 is used to introduce a lavage fluid 1916 into the anatomical region through openings 1904 . Suction lumen 1914 is used to remove lavage fluid 1916 from the anatomical region.
[0191] FIG. 20D shows a sagittal section of a human head showing the general working environment of the lavage devices of FIGS. 20A-20C . Distal end of lavage catheter 1900 is introduced into an anatomical region such as Ethmoid air cell EAC. Lavage catheter 1900 may be introduced into the EAC by an over-the-wire method, through a cannula, or by a variety of methods disclosed in this patent application and in the patents documents incorporated herein by reference. Proximal end of lavage catheter 1900 is detachably connected to a irrigation and suction apparatus 1918 . Irrigation and suction apparatus 1918 provides lavage fluid 1916 to lavage catheter 1900 and also provides suction to remove lavage fluid 1916 from the EAC. Lavage catheter 1900 may similarly be used to diagnose or treat other paranasal sinuses, lachrymal ducts, ducts of salvary glands, Eustachian tubes, and other hollow organs in the ear, nose, throat or mouth.
[0192] FIG. 21 shows a perspective view of a cutting device comprising cutting jaws. Cutting device 2000 comprises a shaft 2002 comprising an upper jaw 2004 and a lower jaw 2006 located on the distal end of shaft 2002 . Proximal region of shaft 2002 comprises a scissor-like device with handles or other suitable control apparatus 2008 that is useable to control the movement of upper jaw 2004 and/or lower jaw 2006 . Upper jaw 2004 and lower jaw 2006 are hinged together so that they can be opened or closed by scissor handles 2008 to bite, grip or cut tissue. In one embodiment, the edges of upper jaw 2004 and lower jaw 2006 are provided with a series of cutting teeth. Alternately, the edges of upper jaw 2004 and lower jaw 2006 may be provided with sharp edges, blunt gripping teeth etc. Shaft 2002 comprises a lumen 2010 . This enables cutting device 2000 to be advanced over an access device such as a guidewire to access a target anatomical region. Examples of materials that can be used to construct cutting device 2000 are stainless steel 304, stainless steel 316, titanium, titanium alloys etc.
[0193] FIG. 21A shows a perspective view of the distal region of the cutting device of FIG. 21 wherein the cutting jaws are closed.
[0194] FIG. 21B shows a perspective view of one embodiment of the jaws of the cutting device of FIG. 21 . Upper jaw 2004 comprises an upper jaw notch 2012 . In one embodiment, upper jaw notch 2012 is semicircular in shape. Similarly, lower jaw 2006 comprises a lower jaw notch 2014 . In one embodiment, lower jaw notch 2014 is semicircular in shape. This design enables a guidewire to pass through a gap in the distal end of the cutting device 2000 even when upper jaw 2004 and lower jaw 2006 are closed. In another embodiment, a guidewire passes through an opening located on either upper jaw 2004 or lower jaw 2006 . Upper jaw 2004 and lower jaw 2006 can also be square, ovoid, trapezoidal or circular in shape.
[0195] FIG. 21C shows a crossectional view of the cutting device in FIG. 21 through plane 21 C- 21 C. Shaft 2002 of cutting device 2000 comprises a lumen 2010 for an access device such as a guidewire. Shaft 2002 further comprises one or more pull wires 2016 that connect upper jaw 2004 and lower jaw 2006 to control apparatus 2008 . When the control apparatus 2008 is moved, pull wires 2016 transmit the movement to upper jaw 2004 and lower jaw 2006 causing them to open or close.
[0196] FIG. 22A shows a perspective view of an alternate embodiment of a device comprising cutting or gripping jaws. Cutting device 2100 comprises a shaft 2102 . Distal end of cutting device 2100 comprises an upper jaw 2104 and a lower jaw 2106 that are hinged together at a first hinge 2108 . Proximal end of upper jaw 2104 comprises a first elongate member 2110 and proximal end of second jaw 2106 comprises a second elongate member 2112 . The proximal end of first elongate member 2110 is connected to a second hinge 2114 which in turn is connected to a third elongate member 2116 . Proximal end of second elongate member 2112 is connected to a third hinge 2118 which in turn is connected to a fourth elongate member 2120 . The proximal ends of third elongate member 2116 and fourth elongate member 2120 are connected by a fourth hinge 2122 to pull wire 2124 that passes through shaft 2102 . FIG. 22A shows cutting device 2100 wherein the upper jaw 2104 and lower jaw 2106 are in an open configuration. When pull wire 2124 is pulled in the proximal direction, fourth hinge 2122 is pulled inside shaft 2102 . This causes the distal ends of third elongate member 2116 and fourth elongate member 2120 to come closer to each other. This in turn causes the proximal ends of first elongate member 2110 and second elongate member 2112 to come closer to each other. This in turn causes upper jaw 2104 and lower jaw 2106 close. Similarly, pushing pull wire 2124 in the distal direction causes upper jaw 2104 and lower jaw 2106 to open. In one embodiment, cutting device 2100 comprises a spring mechanism located between pull wire 2124 and shaft 2102 that biases upper jaw 2104 and lower jaw 2106 in an open or closed configuration.
[0197] FIG. 22B shows a perspective view of the device of FIG. 22A wherein the jaws of the cutting device are in a closed configuration.
[0198] FIGS. 23A-23C show the various steps of a method of puncturing an anatomical region using a flexible, rotating drill shaft. In FIG. 23A , an access catheter 2200 is introduced through a nostril to a location adjacent to an anatomical region 2202 to be punctured. In this example, anatomical region 2202 is a maxillary sinus having a maxillary sinus ostium 2204 . Other examples of the types of anatomical regions 2202 are other paranasal sinuses, lachrymal ducts, bony structures in the ear, nose, throat or mouth etc. Access catheter 2200 can be made of suitable biocompatible materials having a sufficient stiffness such as malleable stainless steel tubes; titanium tubes; fully annealed stainless steel tubes; copper tubes; aluminum tubes; tubular elements made of Pebax, HDPE etc. comprising a hypotube; etc. One or more regions of access catheter 2200 may be shapeable or malleable to allow a user to adjust the shape of access catheter 2200 to a patient's unique anatomy. A substantially stiff access catheter 2200 can be used in situations where extra support is needed for introduction or removal or devices through access catheter 2200 . In an embodiment, a lubricious coating e.g. a Teflon coating is present on the inner surface of access catheter 2200 . The lubricious coating can be made of suitable lubricious materials such as Teflon. In FIG. 23B , a flexible drill shaft 2206 is introduced through access catheter 2200 . Access catheter 2200 helps to align flexible drill shaft 2206 in the anatomical region 2202 in a desired orientation. Flexible drill shaft 2206 can be designed for efficient transfer of unidirectional or bidirectional torque. Flexible drill shaft 2206 can be made from a suitable material having a high torsional stiffness such as heat treated spring steel. Proximal end of flexible drill shaft 2206 is connected to a reversible drive motor that is used to rotate flexible drill shaft 2206 at a desired angular velocity. Flexible drill shaft 2206 comprises a drill bit 2208 located on the distal end of flexible drill shaft 2206 . Drill bit 2208 can range from 0.5 mm-5 mm in diameter. Drill bit 2208 may be made from suitable materials such as tungsten carbide, carbon steel, diamond powder coated metal etc. Drill bit 2208 can have a drill bit design such as twist drill bit, masonry drill bit, spur point bit, step drill bit etc. Flexible drill shaft 2206 is introduced through access catheter 2202 till drill bit 2208 ntouches a target location on anatomical region 2202 to be punctured. In
[0199] FIG. 23C , flexible drill shaft 2206 is rotated so that drill bit 2208 punctures anatomical region 2202 . Such a method and device can be used for a minimally invasive puncturing of suitable anatomical regions for drainage, aeration, introduction of diagnostic or therapeutic devices etc. Such a device and method can also be used for enlarging or clearing natural or artificial openings in anatomical regions. After a desired opening is created or enlarged, access catheter 2200 and flexible drill shaft 2206 are withdrawn from the anatomy. In one embodiment, flexible drill shaft 2206 is a non-rotating shaft having high column strength and comprising a puncturing tip at the distal end of flexible drill shaft 2206 . In another embodiment, flexible drill shaft 2206 acts as an ultrasonic drill by connecting the proximal end of flexible drill shaft to an ultrasonic generator. In another embodiment, access catheter 2200 comprises one or more bearings that reduce friction between access catheter 2200 and flexible drill shaft 2206 .
[0200] FIG. 23D shows a sectional view of an embodiment of a drilling device. Drilling device 2220 comprises a shaft 2222 comprising a proximal rigid portion 2224 and a distal rigid portion 2226 . Shaft 2222 may comprise a deformable (e.g., corrugated, plastically deformable, malleable, etc.) portion 2228 between proximal rigid portion 2224 and distal rigid portion 2226 . Plastically deformable region 2228 allows the shape of drilling device 2220 to be adjusted to facilitate advancement of the device through tortous anatomy, to access to a target anatomical location and/or to achieve a desired positioning or attitude of the bit 2230 within the subject's body. Proximal rigid portion 2224 , distal rigid portion 2226 and plastically deformable or malleable region 2228 can be made of suitable biocompatible materials such as stainless steel e.g. fully annealed stainless steel, copper, aluminum etc. Drilling device 2220 further comprises a rotating drill bit 2230 located at distal end of a rotatable drive member of shaft 2222 . Rotating drill bit 2230 can be made from suitable materials such as tungsten carbide, carbon steel, diamond powder coated metal etc. Rotating drill bit 2230 can be an abrasive coated spherical ball or a twist (e.g., helical) drill bit, masonry drill bit, spur point bit, step drill bit etc. Proximal region of rotating drill bit 2230 is in contact with distal end of shaft 2222 . In order to reduce friction between rotating drill bit 2230 and shaft 2222 , the contact surfaces between rotating drill bit 2230 and shaft 2222 comprise a lubricious coating e.g. a Teflon coating. Proximal region of rotating drill bit 2230 is also attached to a flexible drive shaft 2232 that supplies torque to the rotating drill bit 2230 . In one embodiment, flexible drive shaft 2232 comprises a coil assembly with high torsional stiffness and column strength. In another embodiment, flexible drive shaft 2232 comprises a heat treated spring steel cable. Proximal end of flexible drive shaft 2232 is connected to a reversible drive motor. In one embodiment, rotating drill bit 2230 and flexible drive shaft 2232 comprise a coaxial lumen to enable drilling device 2220 to be introduced over a guidewire into a target anatomy. Such a device can be used for a minimally invasive puncturing of suitable anatomical regions for drainage, aeration, introduction of diagnostic or therapeutic devices etc. Such a device can also be used for enlarging or clearing natural or artificial openings in anatomical regions. It will be appreciated by those of skill in the art that, although this device 2220 is referred to herein as a “drilling device” it may be used for numerous purposes other than “drilling.” For example, this device 2220 may be used to cut, grind, polish or create grooves or depressions in bone, cartilage or other tissue and/or may be used as a screw driver. Thus, in some applications, this drilling device 2220 may alternatively be aptly referred to as a cutter, grinder, rotating rasp, rotating brush, dremmel, polisher, burnisher, boring tool, grooving tool, etc. Also, in some embodiments, the bit may comprise a drive bit that is useable to drive a permanent or resorbable bone screw or other type of screw or anchor. Also, the bit 2230 may be interchangeable and a variety of different bits 2220 may be provided to accomplish various different applications (e.g., grinding, polishing, burnishing, grooving, boring, rasping, debulking, forming indentations or depressions, driving screws, etc.). FIGS. 24A-24C show a sagittal section of an Ethmoid sinus showing various methods of treating Ethmoid sinus diseases by a minimally invasive approach. FIG. 24A shows a sagittal section of an Ethmoid sinus comprising an anterior Ethmoid air cell 2300 , a posterior Ethmoid air cell 2302 and an intermediate Ethmoid air cell 2304 located between anterior Ethmoid air cell 2300 and posterior Ethmoid air cell 2302 . A guide catheter 2306 is introduced to a region inferior to the basal lamella of a middle turbinate. Guide catheter 2306 may comprise a design selected from the various guide catheter designs disclosed herein and in the patent documents incorporated herein by reference. Thereafter, an introducer needle 2308 is introduced through guide catheter 2306 . Introducer needle 2308 comprises a lumen through which devices such as guidewires can be introduced. Introducer needle 2308 can be made of suitable biocompatible materials such as Stainless steel, Nitinol, polymers, polymer-metal composites etc. Introducer needle 2308 is advanced through guide catheter 2306 such that the distal tip of introducer needle 2308 punctures a wall of an Ethmoid air cell e.g. anterior Ethmoid air cell 2300 and enters the Ethmoid air cell. Thereafter, a guidewire 2310 is introduced through introducer needle 2308 into the Ethmoid air cell e.g. anterior Ethmoid air cell 2300 . Thereafter, introducer needle 2308 is removed from the anatomy. In FIG. 24B , a working device is introduced over guidewire 2310 into the Ethmoid air cell. An example of a working device is a balloon catheter 2312 comprising a dilating balloon 2314 . Thereafter, the working device is used to perform a diagnostic or therapeutic procedure e.g. balloon dilation of the introducer needle puncture site to create a drainage channel for sinus secretions. Similarly, other working devices such as dilating or occluding balloons, dilating stents, suction or irrigation devices, needles, polypectomy tools, brushes, energy emitting devices such as ablation devices, laser devices, image-guided devices containing sensors or transmitters, imaging devices, endoscopes, tissue modifying devices such as cutters, biopsy devices, devices for injecting diagnostic or therapeutic agents, lavage devices, drug delivery devices such as substance eluting devices, substance delivery implants etc. may be used to perform diagnostic or therapeutic procedures. The method shown in FIGS. 24A-24B may also be used to create an opening of a suitable diameter to facilitate insertion of other working devices into the Ethmoid air cells. For example, FIG. 24C shows a method of treating Ethmoid sinus diseases by a rongeur. In this method, rongeur 2316 having a distal cutting tip 2318 is introduced through guide catheter 2306 into an Ethmoid air cell via the introducer needle puncture site. Thereafter, rongeur 2316 is used to remove tissue from the Ethmoid air cell.
[0201] FIGS. 24 A′- 24 A″″ show a method of creating drainage channels for sinus secretions in Ethmoid sinus. In FIG. 24 A′, guide catheter 2306 is introduced to a region inferior to the basal lamella of a middle turbinate. Thereafter, introducer needle 2308 is advanced through guide catheter 2306 such that the distal tip of introducer needle 2308 punctures a wall of an Ethmoid air cell e.g. an intermediate Ethmoid air cell 2304 and enters the Ethmoid air cell. In FIG. 24 A″, introducer needle is used to create internal channels in the Ethmoid sinus by puncturing walls of adjacent Ethmoid air cells e.g. anterior Ethmoid air cell 2300 , posterior Ethmoid air cell 2302 etc. In FIG. 24 A′″, introducer needle 2308 and guide catheter 2306 are removed leaving behind internal channels that allow drainage of sinus secretions through the introducer needle puncture site in the intermediate Ethmoid air cell 2304 . Sinus secretions from anterior Ethmoid air cell 2300 or posterior Ethmoid air cell 2302 flow into intermediate Ethmoid air cell 2304 from which they flow out of the Ethmoid sinus. The internal channels as well as the introducer needle puncture site in the intermediate Ethmoid air cell 2304 may be dilated using a balloon catheter as shown in FIGS. 24A-24B . In FIGS. 24 A′- 24 A′″, introducer needle 2308 was introduced into the Ethmoid sinus through intermediate Ethmoid air cell 2304 . Similar procedures may be performed by introducing introducer needle 2304 into the Ethmoid sinus through anterior Ethmoid air cell 2300 or posterior Ethmoid air cell 2302 . In one embodiment, anterior Ethmoid air cell 2300 , posterior Ethmoid air cell 2302 and intermediate Ethmoid air cell 2304 are punctured separately through the basal lamella of a middle turbinate to create separate drainage channels for each Ethmoid air cell as shown in FIG. 24 A″″.
[0202] FIG. 25A shows a perspective view of an embodiment of a microshaver or ostium enlarger device 2400 . Device 2400 comprises a proximal portion 2402 and a distal portion 2403 . Proximal portion 2402 is hollow and comprises a proximal cutting surface 2404 e.g. sharp cutting teeth etc. located on the distal end of proximal portion 2402 . Distal portion 2403 comprises a distal cutting surface 2406 e.g. sharp cutting teeth etc. located on the proximal end of distal portion 2403 . Distal portion 2403 is further connected to a pull shaft 2408 that encloses a guidewire lumen 2410 . Guidewire lumen 2410 allows microshaver 2400 to be introduced over a guidewire GW into a target anatomy. The region between pull shaft 2408 and proximal portion 2402 encloses a suction lumen 2412 . Suction lumen 2412 can be used to remove solid debris or liquids from the target anatomy by suction. Proximal portion 2402 , distal portion 2403 and pull shaft 2408 can be made of suitable biocompatible materials such as stainless steel.
[0203] FIG. 25B shows a crossection of a paranasal sinus showing one way in which the device 2400 of FIG. 25A may be used to remove tissue or matter. The device 2400 is introduced over a guidewire GW into paranasal sinus 2414 . The device 2400 is then positioned such that the tissue or matter is located between proximal cutting surface 2404 and distal cutting surface 2406 . Thereafter, in this embodiment, pull shaft 2408 is pulled in the proximal direction. This causes movement of distal region 2403 in the proximal direction with respect to proximal portion 2402 . This in turn forces cylindrical distal cutter 2406 to be retracted into the interior of the cylindrical proximal cutter 2404 , thereby cutting off or breaking tissue or matter that is captured therebetween. Optionally, in this embodiment, the cylindrical distal cutter 2406 cylindrical proximal cutter 2404 may be rotated relative to the other to further cut or shave tissue. Also, optionally in this embodiment, suction lumen 2412 can be used to remove any solid debris or liquids generated during the procedure.
[0204] FIGS. 25C and 25D show an example of another way in which the device 2400 may be used—i.e., to shave tissue or matter. Examples of anatomical structures that may be shaved by this device 2400 include bone, cartilage and soft tissues of Eustachian tubes, turbinates, lachrymal ducts, anatomical openings such as ostia of paranasal sinuses, ostia of lachrymal ducts, etc. and other regions in the ear, nose, throat or mouth. As shown in FIG. 25C , in this embodiment, there need not be a proximally moveable pull shaft 2408 , but rather the distal cutting surface 2406 may remain positioned within the cylindrical proximal cutting surface 2404 . The cutting surfaces are positioned adjacent to the tissue or matter to be shaved and the cylindrical distal cutter 2406 and/or cylindrical proximal cutter 2404 is/are rotated to shave the tissue or matter. Suction may be applied through lumen 2412 to draw the tissue or matter into slots 2409 such that it will be shaved by the rotating proximal cutter 2404 .
[0205] FIGS. 26A-26C show a device and method for treating a mucocyst of other flowable substance-containing structure (e.g., cyst, hematoma, pustule, etc.) located within a paranasal sinus, ear, nose or throat. In general, the device comprises an elongate shaft 2500 , a penetrator such as a needle 2502 that is advanceable from and retractable into the shaft 2500 to form an opening in the mucocyst or other structure, and a compressor such as a balloon 2506 that is useable to compress the mucocyst or other structure to force its contents to flow out of the opening created by the needle 2502 or other penetrator. Specifically, as shown in the example of FIG. 26A , a guide catheter 2500 is introduced into an anatomical region through an anatomical opening. The outer diameter of guide catheter 2500 is less than the inner diameter of the anatomical opening. In FIGS. 26A-26C , frontal sinus FS is used as an example of an anatomical region. Other examples of anatomical regions are other paranasal sinuses, lachrymal passages, Eustachian tubes and other structures in the ear, nose, throat or mouth etc. Guide catheter 2500 may comprise a design selected from the various guide catheter designs disclosed herein and in the patent documents incorporated herein by reference. A puncturing needle 2502 is then introduced through guide catheter 2500 into the frontal sinus FS. Puncturing needle 2502 has a sharp distal tip and can be made from a variety of materials such as hardened tool steel, stainless steel etc. Puncturing needle 2502 is navigated through the frontal sinus FS such that the distal tip of puncturing needle 2502 punctures a mucocyst 2503 in the frontal sinus FS. Thereafter, puncturing needle 2502 is withdrawn. In FIG. 26B , a guidewire GW is introduced into the frontal sinus FS. Thereafter, a balloon catheter 2504 comprising a balloon 2506 is introduced over guidewire GW into the frontal sinus FS. Balloon 2506 can be made of suitable compliant or semi-compliant materials such as crosslinked polyethylene or other polyolefins, polyurethane, flexible polyvinylchloride, Nylon, etc. Balloon 2506 is then inflated. Inflated balloon 2506 compresses the punctured mucocyst 2503 . This causes drainage of mucocyst secretions into the frontal sinus FS. In FIG. 26C , balloon 2506 is inflated further so that it occupies a volume in the frontal sinus FS and displaces the mucocyst secretions from the frontal sinus FS out through the frontal sinus ostium FSO.
[0206] FIGS. 27A-27B show various steps of a method of treating a mucocyst by a balloon catheter comprising a deployable puncturing needle. In FIG. 27A , a guide catheter 2600 is introduced into an anatomical region through an anatomical opening. The outer diameter of guide catheter 2600 is less than the inner diameter of the anatomical opening. In FIGS. 27A-27B , frontal sinus FS is used as an example of an anatomical region. Other examples of anatomical regions are other paranasal sinuses, lachrymal passages, Eustachian tubes, other ear, nose, throat and mouth structures etc. Guide catheter 2600 may comprise a design selected from the various guide catheter designs disclosed herein and in the patent documents incorporated herein by reference. A balloon catheter 2602 comprising a balloon 2604 and a deployable puncturing needle 2606 is then introduced through guide catheter 2600 into the frontal sinus FS. Balloon 2604 can be made of suitable compliant or semi-compliant materials such as crosslinked polyethylene or other polyolefins, polyurethane, flexible polyvinylchloride, Nylon, etc. Deployable puncturing needle 2606 can be made from a variety of materials such as hardened tool steel, stainless steel etc. Balloon catheter 2604 is oriented in a desired orientation and deployable puncturing needle 2606 is advanced such that the distal tip of deployable puncturing needle 2606 punctures the mucocyst MC. Thereafter, deployable puncturing needle 2606 is withdrawn into balloon catheter 2602 . In FIG. 27B , balloon 2604 is inflated. Inflated balloon 2604 compresses the punctured mucocyst MC. This causes drainage of mucocyst secretions into the frontal sinus FS. Balloon 2604 is then inflated further so that it occupies a volume in the frontal sinus FS and displaces the mucocyst secretions from the frontal sinus FS out through the frontal sinus ostium FSO. In one embodiment, deployable puncturing needle 2606 is located in a needle lumen. Deployable puncturing needle 2606 may be advanced or withdrawn by advancing or withdrawing deployable puncturing needle 2606 through the needle lumen.
[0207] FIGS. 28A-28C show various embodiments of catheters comprising agent delivery needles. In FIG. 28A , catheter 2700 comprises a shaft 2702 having a guidewire lumen. Catheter 2700 further comprises a deployable injecting needle 2704 made from suitable biocompatible materials such as stainless steel. Deployable injecting needle 2704 comprises a lumen for injecting one or more diagnostic or therapeutic agents 2706 into the adjacent anatomy. Deployable injecting needle 2704 is deployed at any suitable angle to the longitudinal axis of shaft 2702 , for example such angle may range from 0 degrees to 135 degrees. In one embodiment, deployable injecting needle 2704 is located in a needle lumen. Deployable injecting needle 2704 is deployed or withdrawn by relative motion of deployable injecting needle 2704 with respect to shaft 2702 . In another embodiment, deployable injecting needle 2704 can be deployed or withdrawn by inflating or deflating a deploying balloon. The deploying balloon can be made from suitable materials such as polyimide, parylene (e.g. C,D,N), silicone, polyurethane, polyethylene terephthalate etc. Catheter 2700 is introduced into a target anatomy and deployable injecting needle 2704 is deployed. Deployable injecting needle 2704 penetrates into the adjacent anatomy. One or more diagnostic or therapeutic agents 2706 are then injected into the adjacent anatomy. In one embodiment, catheter 2700 may be introduced in an anatomical region through a guide catheter 2708 . FIG. 28B shows a perspective view of catheter 2700 of FIG. 28A wherein catheter 2700 further comprises a second deployable injecting needle 2710 . Second deployable injecting needle 2710 comprises a lumen for injecting one or more diagnostic or therapeutic agents 2712 into the adjacent anatomy. In one embodiment, diagnostic or therapeutic agents 2712 are the same as diagnostic or therapeutic agents 2706 . FIG. 28C shows a perspective view of catheter 2700 of FIG. 28A wherein catheter 2700 further comprises a balloon 2714 . In one embodiment, balloon 2714 is a dilating balloon made of suitable non-compliant materials e.g. polyethylene terephthalate etc. This embodiment can be used for both balloon dilation and agent delivery. In another embodiment, balloon 2714 is an anchoring balloon made of suitable non-compliant materials e.g. polyethylene terephthalate etc. or suitable compliant or semi-compliant materials such as crosslinked polyethylene or other polyolefins, polyurethane, flexible polyvinylchloride, Nylon etc. The anchoring balloon can be used to stabilize the position and orientation of catheter 2700 before agent delivery.
[0208] Examples of diagnostic or therapeutic agents that can be delivered by the catheters in FIGS. 28A-28C are pharmaceutically acceptable salt or dosage form of an antimicrobial agent (e.g., antibiotic, antiviral, anti-parasitic, antifungal, etc.), an anesthetic agent with or without a vasoconstriction agents (e.g. Xylocalne with or without Epinephrine, Tetracaine with or without epinephrine, etc.), an analgesic agent, a corticosteroid or other anti-inflammatory (e.g., an NSAID), a decongestant (e.g., vasoconstrictor), a mucous thinning agent (e.g., an expectorant or mucolytic), an agent that prevents of modifies an allergic response (e.g., an antihistamine, cytokine inhibitor, leucotriene inhibitor, IgE inhibitor, immunomodulator), an allergen or another substance that causes secretion of mucous by tissues, hemostatic agents to stop bleeding, anti-proliferative agents, cytotoxic agents e.g. alcohol, biological agents such as protein molecules, stem cells, genes or gene therapy preparations, viral vectors carrying DNA, proteins or mRNA coding for important therapeutic functions or substances etc. Catheters in FIGS. 28A-28C can be used to diagnose or treat anatomical regions such as paranasal sinuses, regions in the Eustachian tubes, lachrymal ducts, ducts of salvary glands, anatomical openings such as ostia of paranasal sinuses, ostia of lachrymal ducts, other regions in the ear, nose, throat or mouth etc.
[0209] FIG. 29A illustrates an embodiment of a displacement catheter to displace and remove secretions in an anatomical region. Displacement catheter 2800 comprises an outer sheath 2802 that encloses a balloon catheter 2804 . Outer sheath 2802 may be flexible or substantially rigid. Outer sheath 2802 may be made of suitable materials such as Pebax, HDPE etc. Outer sheath 2802 may comprise a hypotube made of suitable biocompatible materials such as stainless steel, Nitinol etc. Balloon catheter 2804 comprises a catheter shaft 2806 and a balloon 2808 located on the distal region of catheter shaft 2806 . Catheter shaft 2806 may be made of suitable materials such as Pebax, HDPE etc. Balloon 2808 may be made from suitable compliant or semi-compliant material such as crosslinked polyethylene or other polyolefins, polyurethane, flexible polyvinylchloride, Nylon etc.
[0210] FIG. 29B shows a sectional view of an anatomical region showing a method of displacing secretions by the displacement catheter of FIG. 29A . Displacement catheter 2800 is introduced in an anatomical region. In FIG. 29B , a Maxillary sinus MS is used as an example of an anatomical region. Other examples of anatomical regions that can be treated using displacement catheter 2800 are other paranasal sinuses, lachrymal passages, Eustachian tubes etc. Displacement catheter 2800 can be advanced into an anatomical region through natural openings e.g. ostia of sinuses or artificially created openings. In this example, displacement catheter 2800 is advanced into the Maxillary sinus through a natural opening such as a maxillary sinus ostium MSO such that the distal end of displacement catheter is near the distal region of Maxillary sinus MS. Outer diameter of outer sheath 2802 is less than inner diameter of Maxillary sinus ostium MSO. Thereafter, outer sheath 2802 is withdrawn gradually by pulling outer sheath 2802 in the proximal direction over balloon catheter 2804 . Simultaneously, balloon 2808 is inflated by a suitable inflating medium such as saline mixed with radiographic contrast. This causes distal region of balloon 2804 to inflate before the proximal region of balloon 2804 . Balloon 2804 gradually begins to occupy available volume in the Maxillary sinus MS and thus displaces secretions 2810 out of the Maxillary sinus MS through the Maxillary sinus ostium MSO. In one embodiment of balloon 2804 , distal region of balloon 2804 has a higher compliance than proximal regions of balloon 2804 . In another embodiment, balloon 2804 comprises multiple compartments such that each compartment can be inflated independently of other compartments. Balloon 2804 may be detachably connected to catheter shaft 2806 to enable permanent occlusion of the anatomical region. Balloon 2804 may also comprise a variety of drug delivery mechanisms including drug eluting coatings, drug eluting pores for eluting a drug dissolved in the inflating medium etc.
[0211] FIG. 30 shows a perspective view of an embodiment of an ultrasonic drilling device. Drilling device 2900 comprises a rigid or flexible drilling shaft 2902 . Drilling shaft 2902 can be made of suitable materials such as tungsten carbide flexible wire. The proximal end of drilling shaft 2902 is connected to a piezoelectric crystal 2904 such as a quartz (SiO2) or barium titanate (BaTiO3) crystal. Piezoelectric crystal 2904 may have a layer of backing material 2906 on the proximal surface of piezoelectric crystal 2904 . Piezoelectric crystal 2904 is connected by electrodes 2908 to an electric power source 2910 . Electric power source 2910 delivers a suitable current via electrodes 2908 to piezoelectric crystal 2904 to cause piezoelectric crystal 2904 to vibrate at an ultrasonic frequency. The vibration of piezoelectric crystal 2904 is transmitted to drilling shaft 2902 . In one embodiment, drilling shaft 2902 is connected to piezoelectric crystal 2904 by a coupler 2912 .
[0212] FIGS. 30A-30B show a sectional view of an anatomical region showing a method of enlarging a natural or artificially created anatomical opening using the drilling device of FIG. 30 . The drilling device may also be used to create new openings in an anatomical region. Distal part of drilling device 2900 comprising drilling shaft 2902 of diameter D.sub.2 is positioned such that the distal end of drilling shaft 2902 touches an anatomical opening e.g. a sphenoid sinus ostium SSO to be dilated. The anatomical opening has an initial diameter D.sub.1. Thereafter, current from electric power source 2910 is switched on, which in turn causes drilling shaft 2902 to vibrate in the axial direction. The vibration of drilling shaft 2902 causes distal tip of drilling shaft 2902 to impact the anatomical opening. In FIG. 30B , the impact of drilling shaft 2902 causes dilation of the anatomical opening from an initial diameter D.sub.1 to a diameter D.sub.2.
[0213] Similarly, other embodiments of drilling devices may be used to puncture, remodel or change the shape, size or configuration of anatomical structures such as paranasal sinuses, Eustachian tubes, middle ear, nasopharynx, Lachrymal ducts or other anatomical regions in the ear, nose, throat or mouth. Such drilling devices may comprise for example elements for ablation or delivery of energy such as laser, RF, thermal shock waves etc.
[0214] FIG. 31 shows a sectional view of an embodiment of a catheter for providing an internal cast for fractured bony cavities. Catheter 3000 comprises a shaft 3002 comprising a plurality of inflating elements e.g. inflating balloon in the distal region of shaft 3002 . In the example shown in FIG. 31 , catheter 3000 comprises a proximal interior balloon 3004 , a distal interior balloon 3006 and an intermediate interior balloon 3008 located between proximal interior balloon 3004 and distal interior balloon 3006 . Catheter 3000 further comprises an intermediate balloon 3010 covering proximal interior balloon 3004 and intermediate interior balloon 3008 as shown in FIG. 31 . Catheter 3000 further comprises an outer balloon 3012 that covers intermediate balloon 3010 and a portion of distal interior balloon 3006 as shown in FIG. 31 . The balloons on catheter 3000 can be inflated independently of each other. For example proximal interior balloon 3004 can be inflated by a proximal interior balloon lumen 3014 , distal interior balloon 3006 can be inflated by a distal interior balloon inflation lumen 3016 and intermediate interior balloon 3008 can be inflated by an intermediate balloon inflation lumen 3018 . The balloons on catheter 3000 may be made from suitable compliant or semi-compliant material such as crosslinked polyethylene or other polyolefins, polyurethane, flexible polyvinylchloride, Nylon etc. or from suitable non-compliant materials e.g. polyethylene terephthalate etc. The balloons on catheter 3000 may be coated with a variety of coatings including lubricious coatings, drug eluting coatings etc. FIG. 31A shows a crossection through the outer balloon 3012 in the catheter 3000 of FIG. 31 through plane 31 A- 31 A. Outer balloon 3012 comprises a balloon material 3020 made from suitable compliant or semi-compliant material such as crosslinked polyethylene or other polyolefins, polyurethane, flexible polyvinylchloride, Nylon etc. or from suitable non-compliant materials e.g. polyethylene terephthalate etc. A coating 3022 is located on the outer surface of balloon material 3020 . Examples of materials that can be used in coating 3022 are contrast agents, pharmaceutically acceptable salt or dosage form of an antimicrobial agent (e.g., antibiotic, antiviral, anti-parasitic, antifungal, etc.), an anesthetic agent with or without a vasoconstriction agents (e.g. Xylocalne with or without Epinephrine, Tetracaine with or without epinephrine, etc.), an analgesic agent, a corticosteroid or other anti-inflammatory (e.g., an NSAID), a decongestant (e.g., vasoconstrictor), a mucous thinning agent (e.g., an expectorant or mucolytic), an agent that prevents of modifies an allergic response (e.g., an antihistamine, cytokine inhibitor, leucotriene inhibitor, IgE inhibitor, immunomodulator), an allergen or another substance that causes secretion of mucous by tissues, hemostatic agents to stop bleeding, anti-proliferative agents, cytotoxic agents e.g. alcohol, biological agents such as protein molecules, stem cells, genes or gene therapy preparations etc.
[0215] FIGS. 31B-31D shows various steps of a method of providing an internal cast for a fractured bony cavity using the catheter shown in FIG. 31 . In FIGS. 31B-31D , Maxillary sinus MS is used as an example of bony cavity that can be treated using catheter 3000 . FIG. 31B shows a patient with a fractured bony cavity e.g. a fractured Maxillary sinus MS having one or more fractured bones 3024 . In FIG. 31C , catheter 3000 is introduced into the Maxillary sinus MS through a natural opening e.g. an ostium or an artificially created opening. In FIG. 31D , one or more balloons on catheter 3000 are sequentially inflated to push fractured bones 3024 into their original un-fractured configuration. Catheter 3000 may then be left in place for a desired period ranging from a few minutes to several days during which fractured bones 3024 begin to heal in their original un-fractured configuration. After catheter 3000 has been left in place for the desired period, catheter 3000 is removed by deflating the balloons and withdrawing catheter 3000 from the anatomy. Thus, catheter 3000 provides an internal cast for a fractured bony cavity. Various embodiments of catheter 3000 may be used for crating internal casts for fractured paranasal sinuses, lachrymal passages, Eustachian tubes, other structures in the ear, nose, throat, mouth etc.
[0216] The various devices and methods disclosed herein may be used in conjunction with various surgical navigations systems. FIGS. 32 and 32A show an embodiment of a surgical navigation system comprising electromagnetic sensors. Examples of electromagnetic sensors that can be used with the present invention are electromagnetic sensors of an electromagnetic surgical navigation system such as GE InstaTrak™ 3500 plus system etc. FIG. 32 shows a perspective view of a patient's head showing the location of external ear canal electromagnetic sensors 3100 and teeth electromagnetic sensors 3102 . External ear canal electromagnetic sensors 3100 are introduced through an ear canal into a region adjacent to a tympanum. Teeth electromagnetic sensors 3102 are attached to one or more teeth of the patient. In one embodiment, teeth electromagnetic sensors 3102 are attached to teeth using an adhesive. In an alternate embodiment, teeth electromagnetic sensors 3102 are attached to braces or caps which in turn are attached to teeth. The braces or caps can be made of suitable materials that cause minimal artifacts on CT or MRI images. An example of such a material is aluminum alloy 2017-T4 which causes minimal artifacts on a CT scan image. Other locations of electromagnetic sensors include skin (e.g. a skin patch comprising an electromagnetic sensor), a head frame etc. The patient's head is imaged using an imaging modality such as CT or MRI. External ear canal electromagnetic sensors 3100 and teeth electromagnetic sensors 3102 are passively imaged by the imaging modality and thus act as fiducial markers.
[0217] FIGS. 32 and 32A illustrate a surgical navigation system comprising fiducial markers that have electromagnetic sensors. Various other embodiments of fiducial markers such as passively imaged fiducial markers or active sensors or transmitters may be used in conjunction with the various methods and devices disclosed herein. The fiducial markers may be located on relevant anatomical regions such as teeth, ear canals, skull bones, frames fixed to rigid bones etc. The fiducial markers may be used with a variety of modalities including but not limited to electromagnetic, infrared, ultrasonic, radio-frequency, MRI, CT, Fluoroscopic or other 2D or 3D image guided systems for the head, neck or other anatomical regions manufactured by companies such as Biosense, Stryker, Brainlab, Xomed, GE/VTI etc.
[0218] FIG. 32A shows an enlarged view of region 32 A in FIG. 32 . Teeth electromagnetic sensors 3102 are connected to the electromagnetic surgical navigation system by removable leads 3104 . In another embodiment, external ear canal electromagnetic sensors 3100 or teeth electromagnetic sensors 3102 are connected to the electromagnetic surgical navigation system by telemetry. During a procedure, external ear canal electromagnetic sensors 3100 and/or teeth electromagnetic sensors 3102 are actively imaged by suitable electromagnetic surgical navigation systems such as GE InstaTrak™ 3500 plus system etc. Thereafter, data from imaging modality such as CT or MRI and the electromagnetic surgical navigation system is merged to obtain a three dimensional map of the anatomy showing the electromagnetic sensors. The three dimensional map can then be used for image guided procedures such as diagnostic or therapeutic procedures of paranasal sinuses, Eustachian tubes, lachrymal ducts, other ear, nose, throat or mouth structures etc.
[0219] Other image guided surgery systems such as infrared sensor based systems e.g. Stryker Leibinger® Navigation System can also be used in conjunction with one or more methods or devices disclosed herein.
[0220] FIG. 33 shows a section of the anatomical region around a Eustachian tube (ET) showing a diagnostic or therapeutic procedure being performed by devices inserted through the pharyngeal ostium of the Eustachian tube. FIG. 33 shows a guidewire GW inserted into a desired region in the ET through the Nasopharynx and a diagnostic or therapeutic being performed by a device introduced into the Eustachian tube over guidewire GW.
[0221] FIG. 33A shows an enlarged view of region 33 A in FIG. 33 showing the anatomical region around a Eustachian tube (ET) showing a diagnostic or therapeutic procedure being performed by devices inserted through the pharyngeal ostium of the Eustachian tube. In one embodiment, guidewire GW comprises an anchoring balloon 3200 located on the distal region of guidewire GW. Anchoring balloon 3200 is inflated after positioning guidewire GW at a target location. Anchoring balloon 3200 anchors guidewire GW to the adjacent anatomy and prevents accidental repositioning of guidewire GW during a diagnostic or therapeutic procedure. Anchoring balloon 3200 may be made from suitable compliant or semi-compliant material such as crosslinked polyethylene or other polyolefins, polyurethane, flexible polyvinylchloride, Nylon etc. Guidewire GW may comprise anchoring elements other than anchoring balloon 3200 such as a notch on guidewire GW, a bent region on guidewire GW, a self expanding element, a hook, a coiled element etc. In another embodiment, guidewire GW comprises a sensor 3202 located on the distal region of guidewire GW. Sensor 3202 enables guidewire GW to be used in conjunction with a suitable surgical navigation system. In one embodiment, sensor 3202 is an electromagnetic sensor used in conjunction with an electromagnetic surgical navigation system such as GE InstaTrak™ 3500 plus system etc. One or more sensor 3202 or other types of surgical navigation sensors or transmitters may also be located on other diagnostic or therapeutic devices disclosed herein. Sensor 3202 may be used in conjunction with a stationary sensor 3204 located in the external ear. The combination of sensor 3202 and stationary sensor 3204 enables guidewire GW to be accurately positioned in a target region. In an embodiment, a radioopaque plug 3206 is inserted from the external ear to a region adjacent to an eardrum. Radioopaque plug 3206 serves as a fiducial marker during preoperative scanning of the patient and thus enables a physician to accurately position a diagnostic or therapeutic device close to the eardrum. Other image guidance methods and devices can also be used in conjunction with diagnostic or therapeutic procedures disclosed herein. FIG. 33A also shows a diagnostic or therapeutic device 3208 comprising a shaft 3210 and a working element 3212 e.g. a dilating balloon being introduced over guidewire GW. Diagnostic or therapeutic device 3208 may comprise a radiopaque marker 3214 .
[0222] FIG. 33B shows a front view of a human head with a portion of the face removed to show an embodiment of a method of introducing a guidewire into a Eustachian tube. In FIG. 33B , a guide catheter 3250 is introduced through a nostril into the Nasopharynx. Distal portion of guide catheter 3250 may comprise a bent or angled region. For example, such bent or angled region may form e an internal angle ranging from 45 degrees to 150 degrees. Guide catheter 3250 can be constructed using one of the various designs disclosed herein and in the patent documents incorporated herein by reference. Guide catheter 3250 is positioned in the Nasopharynx such that the distal tip of guide catheter 3250 is located near a nasopharyngeal opening of a Eustachian tube. Thereafter, a guidewire GW is introduced through guide catheter 3250 into the Eustachian tube. Guidewire GW can then be used to advance one or more diagnostic or therapeutic devices into the Eustachian tube to perform one or more diagnostic or therapeutic procedures.
[0223] FIGS. 34A-34D illustrate various examples of working elements that can be located on the diagnostic or therapeutic device in FIG. 33 . FIG. 34 A shows an example of a working element comprising a dilating balloon. Dilating balloon 3312 can be made from a suitable non-compliant materials e.g. polyethylene terephthalate, Nylon etc. Similarly, devices shown in FIGS. 14 , 15 , 16 , 17 and 18 may also be used to treat a Eustachian tube as shown in FIG. 33 .
[0224] FIG. 34B shows an example of a working element comprising a dilating balloon loaded with a balloon-expandable stent. Dilating balloon 3314 can be made from a suitable non-compliant materials e.g. polyethylene terephthalate, Nylon etc. Several types of stent designs can be used to construct stent 3316 such as metallic tube designs, polymeric tube designs, chain-linked designs, spiral designs, rolled sheet designs, single wire designs etc. These designs may have an open celled or closed celled structure. A variety of fabrication methods can be used for fabricating stent 3316 including but not limited to laser cutting a metal or polymer element, welding metal elements etc. A variety of materials can be used for fabricating stent 3316 including but not limited to metals, polymers, foam type materials, plastically deformable materials, super elastic materials etc. A variety of features can be added to stent 3316 including but not limited to radiopaque coatings, drug elution mechanisms to elute anti-inflammatory agents, antibiotics etc. In one embodiment, stent 3316 is bioabsorbable. Working elements may also comprise a self-expanding stent instead of a pressure-expandable stent.
[0225] FIG. 34C shows an example of a working element comprising a lavage element. Lavage element 3318 comprises a plurality of lavage openings 3320 . Lavage openings are connected to a lavage lumen in shaft 3210 through which suitable lavage media such as solutions containing contrast agents, pharmaceutically acceptable salt or dosage form of an antimicrobial agent (e.g., antibiotic, antiviral, anti-parasitic, antifungal, etc.), an anesthetic agent with or without a vasoconstriction agents (e.g. Xylocalne with or without Epinephrine, Tetracaine with or without epinephrine, etc.), an analgesic agent, a corticosteroid or other anti-inflammatory (e.g., an NSAID), a decongestant (e.g., vasoconstrictor), a mucous thinning agent (e.g., an expectorant or mucolytic), an agent that prevents of modifies an allergic response (e.g., an antihistamine, cytokine inhibitor, leucotriene inhibitor, IgE inhibitor, immunomodulator), an allergen or another substance that causes secretion of mucous by tissues, hemostatic agents to stop bleeding, anti-proliferative agents, cytotoxic agents e.g. alcohol, biological agents such as protein molecules, stem cells, genes or gene therapy preparations etc. can be delivered. In one embodiment, a fraction of lavage openings 3320 are connected to an aspiration lumen to aspirate the lavage media out of the Eustachian tube.
[0226] FIG. 34D shows an example of a working element comprising a substance delivery reservoir. Substance delivery reservoir 3322 may be fully or partially biodegradable or non-biodegradable. In one embodiment, substance delivery reservoir 3322 is made of a suitable biocompatible material such as hydrogel (e.g. collage hydrogel). In another embodiment, substance delivery reservoir 3322 comprises a porous matrix formed of a porous material such as a flexible or rigid polymer foam, cotton wadding, gauze, etc. Examples of biodegradable polymers that may be foamed or otherwise rendered porous include polyglycolide, poly-L-lactide, poly-D-lactide, poly(amino acids), polydioxanone, polycaprolactone, polygluconate, polylactic acid-polyethylene oxide copolymers, modified cellulose, collagen, polyorthoesters, polyhydroxybutyrate, polyanhydride, polyphosphoester, poly(alpha-hydroxy acid) and combinations thereof. Examples of non-biodegradable polymers that may be foamed or otherwise rendered porous include polyurethane, polycarbonate, silicone elastomers etc. Substance delivery reservoir 3322 may also include one or more embodiments disclosed in U.S. patent application Ser. No. 10/912,578 entitled “Implantable Device and Methods for Delivering Drugs and Other Substances to Treat Sinusitis and Other Disorders” filed on Aug. 4, 2004, the entire disclosure of which is expressly incorporated herein by reference. The substance delivery reservoir 3322 or any substance delivery devices described in this application may be used to deliver various types of therapeutic or diagnostic agents. The term “diagnostic or therapeutic substance” as used herein is to be broadly construed to include any feasible drugs, prodrugs, proteins, gene therapy preparations, cells, diagnostic agents, contrast or imaging agents, biologicals, etc. Such substances may be in bound or free form, liquid or solid, colloid or other suspension, solution or may be in the form of a gas or other fluid or nan-fluid. For example, in some applications where it is desired to treat or prevent a microbial infection, the substance delivered may comprise pharmaceutically acceptable salt or dosage form of an antimicrobial agent (e.g., antibiotic, antiviral, antiparacytic, antifungal, etc.), a corticosteroid or other anti-inflammatory (e.g., an NSAID), a decongestant (e.g., vasoconstrictor), a mucous thinning agent (e.g., an expectorant or mucolytic), an agent that prevents of modifies an allergic response (e.g., an antihistamine, cytokine inhibitor, leucotriene inhibitor, IgE inhibitor, immunomodulator), etc.
[0227] Some nonlimiting examples of antimicrobial agents that may be used in this invention include acyclovir, amantadine, aminoglycosides (e.g., amikacin, gentamicin and tobramycin), amoxicillin, amoxicillin/clavulanate, amphotericin B, ampicillin, ampicillin/sulbactam, atovaquone, azithromycin, cefazolin, cefepime, cefotaxime, cefotetan, cefpodoxime, ceftazidime, ceftizoxime, ceftriaxone, cefuroxime, cefuroxime axetil, cephalexin, chloramphenicol, clotrimazole, ciprofloxacin, clarithromycin, clindamycin, dapsone, dicloxacillin, doxycycline, erythromycin, fluconazole, foscarnet, ganciclovir, atifloxacin, imipenem/cilastatin, isoniazid, itraconazole, ketoconazole, metronidazole, nafcillin, nafcillin, nystatin, penicillin, penicillin G, pentamidine, piperacillin/tazobactam, rifampin, quinupristin-dalfopristin, ticarcillin/clavulanate, trimethoprim/sulfamethoxazole, valacyclovir, vancomycin, mafenide, silver sulfadiazine, mupirocin (e.g., Bactroban Nasal®, Glaxo SmithKline, Research Triangle Park, N.C.), nystatin, triamcinolone/nystatin, clotrimazole/betamethasone, clotrimazole, ketoconazole, butoconazole, miconazole, tioconazole, detergent-like chemicals that disrupt or disable microbes (e.g., nonoxynol-9, octoxynol-9, benzalkonium chloride, menfegol, and N-docasanol); chemicals that block microbial attachment to target cells and/or inhibits entry of infectious pathogens (e.g., sulphated and sulponated polymers such as PC-515 (carrageenan), Pro-2000, and Dextrin 2 Sulphate); antiretroviral agents (e.g., PMPA gel) that prevent retroviruses from replicating in the cells; genetically engineered or naturally occurring antibodies that combat pathogens such as anti-viral antibodies genetically engineered from plants known as “plantibodies;” agents which change the condition of the tissue to make it hostile to the pathogen (such as substances which alter mucosal pH (e.g., Buffer Gel and Acidform); non-pathogenic or “friendly” microbes that cause the production of hydrogen peroxide or other substances that kill or inhibit the growth of pathogenic microbes (e.g., lactobacillus ); antimicrobial proteins or peptides such as those described in U.S. Pat. No. 6,716,813 (Lin et al.,) which is expressly incorporated herein by reference or antimicrobial metals (e.g., colloidal silver).
[0228] Additionally or alternatively, in some applications where it is desired to treat or prevent inflammation the substances delivered in this invention may include various steroids or other anti-inflammatory agents (e.g., nonsteroidal anti-inflammatory agents or NSAIDS), analgesic agents or antipyretic agents. For example, corticosteroids that have previously administered by intranasal administration may be used, such as beclomethasone (Vancenase® or Beconase®), flunisolide (Nasalide®), fluticasone proprionate (Flonase®), triamcinolone acetonide (Nasacort®), budesonide (Rhinocort Aqua®), loterednol etabonate (Locort) and mometasone (Nasonex®). Other salt forms of the aforementioned corticosteroids may also be used. Also, other non-limiting examples of steroids that may be useable in the present invention include but are not limited to aclometasone, desonide, hydrocortisone, betamethasone, clocortolone, desoximetasone, fluocinolone, flurandrenolide, mometasone, prednicarbate; amcinonide, desoximetasone, diflorasone, fluocinolone, fluocinonide, halcinonide, clobetasol, augmented betamethasone, diflorasone, halobetasol, prednisone, dexamethasone and methylprednisolone. Other anti-inflammatory, analgesic or antipyretic agents that may be used include the nonselective COX inhibitors (e.g., salicylic acid derivatives, aspirin, sodium salicylate, choline magnesium trisalicylate, salsalate, diflunisal, sulfasalazine and olsalazine; para-aminophenol derivatives such as acetaminophen; indole and indene acetic acids such as indomethacin and sulindac; heteroaryl acetic acids such as tolmetin, dicofenac and ketorolac; arylpropionic acids such as ibuprofen, naproxen, flurbiprofen, ketoprofen, fenoprofen and oxaprozin; anthranilic acids (fenamates) such as mefenamic acid and meloxicam; enolic acids such as the oxicams (piroxicam, meloxicam) and alkanones such as nabumetone) and Selective COX-2 Inhibitors (e.g., diaryl-substituted furanones such as rofecoxib; diaryl-substituted pyrazoles such as celecoxib; indole acetic acids such as etodolac and sulfonanilides such as nimesulide)
[0229] Additionally or alternatively, in some applications, such as those where it is desired to treat or prevent an allergic or immune response and/or cellular proliferation, the substances delivered in this invention may include a) various cytokine inhibitors such as humanized anti-cytokine antibodies, anti-cytokine receptor antibodies, recombinant (new cell resulting from genetic recombination) antagonists, or soluble receptors; b) various leucotriene modifiers such as zafirlukast, montelukast and zileuton; c) immunoglobulin E (IgE) inhibitors such as Omalizumab (an anti-IgE monoclonal antibody formerly called rhu Mab-E25) and secretory leukocyte protease inhibitor) and d) SYK Kinase inhibitoers such as an agent designated as “R-112” manufactured by Rigel Pharmaceuticals, Inc, or South San Francisco, Calif.
[0230] Additionally or alternatively, in some applications, such as those where it is desired to shrink mucosal tissue, cause decongestion or effect hemostasis, the substances delivered in this invention may include various vasoconstrictors for decongestant and or hemostatic purposes including but not limited to pseudoephedrine, xylometazoline, oxymetazoline, phenylephrine, epinephrine, etc.
[0231] Additionally or alternatively, in some applications, such as those where it is desired to facilitate the flow of mucous, the substances delivered in this invention may include various mucolytics or other agents that modify the viscosity or consistency of mucous or mucoid secretions, including but not limited to acetylcysteine (Mucomyst™, Mucosil™) and guaifenesin.
[0232] In one particular embodiment, the substance delivered by this invention comprises a combination of an anti-inflammatory agent (e.g. a steroid or an NSAID) and a mucolytic agent.
[0233] Additionally or alternatively, in some applications such as those where it is desired to prevent or deter histamine release, the substances delivered in this invention may include various mast cell stabilizers or drugs which prevent the release of histamine such as cromolyn (e.g., Nasal Chrom®) and nedocromil.
[0234] Additionally or alternatively, in some applications such as those where it is desired to prevent or inhibit the effect of histamine, the substances delivered in this invention may include various antihistamines such as azelastine (e.g., Astylin®), diphenhydramine, loratidine, etc.
[0235] Additionally or alternatively, in some embodiments such as those where it is desired to dissolve, degrade, cut, break or remodel bone or cartilage, the substances delivered in this invention may include substances that weaken or modify bone and/or cartilage to facilitate other procedures of this invention wherein bone or cartilage is remodeled, reshaped, broken or removed. One example of such an agent would be a calcium chelator such as EDTA that could be injected or delivered in a substance delivery implant next to a region of bone that is to be remodeled or modified. Another example would be a preparation consisting of or containing bone degrading cells such as osteoclasts. Other examples would include various enzymes of material that may soften or break down components of bone or cartilage such as collagenase (CGN), trypsin, trypsin/EDTA, hyaluronidase, and tosyllysylchloromethane (TLCM).
[0236] Additionally or alternatively, in some applications, the substances delivered in this invention may include other classes of substances that are used to treat rhinitis, nasal polyps, nasal inflammation, and other disorders of the ear, nose and throat including but not limited to anti-cholinergic agents that tend to dry up nasal secretions such as ipratropium (Atrovent Nasal®), as well as other agents not listed here.
[0237] Additionally or alternatively, in some applications such as those where it is desired to draw fluid from polyps or edematous tissue, the substances delivered in this invention may include locally or topically acting diuretics such as furosemide and/or hyperosmolar agents such as sodium chloride gel or other salt preparations that draw water from tissue or substances that directly or indirectly change the osmolar content of the mucous to cause more water to exit the tissue to shrink the polyps directly at their site.
[0238] Additionally or alternatively, in some applications such as those wherein it is desired to treat a tumor or cancerous lesion, the substances delivered in this invention may include antitumor agents (e.g., cancer chemotherapeutic agents, biological response modifiers, vascularization inhibitors, hormone receptor blockers, cryotherapeutic agents or other agents that destroy or inhibit neoplasia or tumorigenesis) such as; alkylating agents or other agents which directly kill cancer cells by attacking their DNA (e.g., cyclophosphamide, isophosphamide), nitrosoureas or other agents which kill cancer cells by inhibiting changes necessary for cellular DNA repair (e.g., carmustine (BCNU) and lomustine (CCNU)), antimetabolites and other agents that block cancer cell growth by interfering with certain cell functions, usually DNA synthesis (e.g., 6 mercaptopurine and 5-fluorouracil (5FU), antitumor antibiotics and other compounds that act by binding or intercalating DNA and preventing RNA synthesis (e.g., doxorubicin, daunorubicin, epirubicin, idarubicin, mitomycin-C and bleomycin) plant (vinca) alkaloids and other anti-tumor agents derived from plants (e.g., vincristine and vinblastine), steroid hormones, hormone inhibitors, hormone receptor antagonists and other agents which affect the growth of hormone-responsive cancers (e.g., tamoxifen, herceptin, aromatase ingibitors such as aminoglutethamide and formestane, trriazole inhibitors such as letrozole and anastrazole, steroidal inhibitors such as exemestane), antiangiogenic proteins, small molecules, gene therapies and/or other agents that inhibit angiogenesis or vascularization of tumors (e.g., meth-1, meth-2, thalidomide), bevacizumab (Avastin), squalamine, endostatin, angiostatin, Angiozyme, AE-941 (Neovastat), CC-5013 (Revimid), medi-522 (Vitaxin), 2-methoxyestradiol (2ME2, Panzem), carboxyamidotriazole (CAI), combretastatin A4 prodrug (CA4P), SU6668, SU11248, BMS-275291, COL-3, EMD 121974, IMC- 1 C11, IM862, TNP-470, celecoxib (Celebrex), rofecoxib (Vioxx), interferon alpha, interleukin-12 (IL-12) or any of the compounds identified in Science Vol. 289, Pages 1197-1201 (Aug. 17, 2000) which is expressly incorporated herein by reference, biological response modifiers (e.g., interferon, bacillus calmette-guerin (BCG), monoclonal antibodies, interluken 2, granulocyte colony stimulating factor (GCSF), etc.), PGDF receptor antagonists, herceptin, asparaginase, busulphan, carboplatin, cisplatin, carmustine, cchlorambucil, cytarabine, dacarbazine, etoposide, flucarbazine, fluorouracil, gemcitabine, hydroxyurea, ifosphamide, irinotecan, lomustine, melphalan, mercaptopurine, methotrexate, thioguanine, thiotepa, tomudex, topotecan, treosulfan, vinblastine, vincristine, mitoazitrone, oxaliplatin, procarbazine, streptocin, taxol, taxotere, analogs/congeners and derivatives of such compounds as well as other antitumor agents not listed here.
[0239] Additionally or alternatively, in some applications such as those where it is desired to grow new cells or to modify existing cells, the substances delivered in this invention may include cells (mucosal cells, fibroblasts, stem cells or genetically engineered cells) as well as genes and gene delivery vehicles like plasmids, adenoviral vectors or naked DNA, mRNA, etc. injected with genes that code for anti-inflammatory substances, etc., and, as mentioned above, osteoclasts that modify or soften bone when so desired, cells that participate in or effect mucogenesis or ciliagenesis, etc.
[0240] Additionally or alternatively to being combined with a device and/or a substance releasing modality, it may be ideal to position the device in a specific location upstream in the mucous flow path (i.e. frontal sinus or ethmoid cells). This could allow the deposition of fewer drug releasing devices, and permit the “bathing” of all the downstream tissues with the desired drug. This utilization of mucous as a carrier for the drug may be ideal, especially since the concentrations for the drug may be highest in regions where the mucous is retained; whereas non-diseased regions with good mucous flow will be less affected by the drug. This could be particularly useful in chronic sinusitis, or tumors where bringing the concentration of drug higher at those specific sites may have greater therapeutic benefit. In all such cases, local delivery will permit these drugs to have much less systemic impact. Further, it may be ideal to configure the composition of the drug or delivery system such that it maintains a loose affinity to the mucous permitting it to distribute evenly in the flow. Also, in some applications, rather than a drug, a solute such as a salt or other mucous soluble material may be positioned at a location whereby mucous will contact the substance and a quantity of the substance will become dissolved in the mucous thereby changing some property (e.g., pH, osmolarity, etc) of the mucous. In some cases, this technique may be used to render the mucous hyperosmolar so that the flowing mucous will draw water and/or other fluid from polyps, edematous mucosal tissue, etc., thereby providing a drying or desiccating therapeutic effect.
[0241] Additionally or alternatively to substances directed towards local delivery to affect changes within the sinus cavity, the nasal cavities provide unique access to the olfactory system and thus the brain. Any of the devices and methods described herein may also be used to deliver substances to the brain or alter the functioning of the olfactory system. Such examples include, the delivery of energy or the deposition of devices and/or substances and/or substance delivering implant(s) to occlude or alter olfactory perception, to suppress appetite or otherwise treat obesity, epilepsy (e.g., barbiturates such as phenobarbital or mephoobarbital; iminostilbenes such as carbamazepine and oxcarbazepine; succinimides such as ethylsuximide; valproic acid; benzodiazepines such as clonazepam, clorazepate, diazepam and lorazepam, gabapentin, lamotrigine, acetazolamide, felbamate, levetiraceam, tiagabine, topiramate, zonisamide, etc.), personality or mental disorders (e.g., antidepressants, antianxiety agents, antipsychotics, etc.), chronic pain, Parkinson's disease (e.g., dopamine receptor agonists such as bromocriptine, pergolide, ropinitrol and pramipexole; dopamine precursors such as levodopa; COMT inhibitors such as tolcapone and entacapone; selegiline; muscarinic receptor antagonists such as trihexyphenidyl, benztropine and diphenhydramine) and Alzheimer's disease, Huntington's disease or other dementias, disorders of cognition or chronic degenerative diseases (e.g. tacrine, donepezil, rivastigmine, galantamine, fluoxetine, carbamazepine, clozapine, clonazepam and proteins or genetic therapies that inhibit the formation of beta-amyloid plaques), etc.
[0242] The working element need not necessarily be a substance delivery reservoir 3322 . For example, another type of working element useable in this invention is a laser device. In one embodiment, the laser device may comprise an optical fiber that delivers laser energy through the distal region of the optical fiber. Typical examples of lasers that can be used in the present invention are Nd:YAG lasers, Ho:NAG lasers, short pulsed laser systems such as excimer lasers (wavelength: 308 nm, pulse length full width at half maximum height: 60 ns), dye lasers (wavelength: 504 nm, pulse length full width at half maximum height: 1200 ns), tunable die lasers, KTP lasers, argon lasers, Alexandrite lasers (wavelength: 755 nm, pulse length full width at half maximum height: 300-500 ns) etc. Such a laser device may also be used in conjunction with or as a part of any method, system or device disclosed in this patent application for laser-assisted ablation or cutting, laser-assisted cauterization or other laser-assisted methods of treating sinusitis, mucocysts, tumors, polyps, occlusions, obstructions, edema or other conditions of the paranasal sinuses, Eustachian tubes, Lachrymal ducts, salivary glands and other hard or soft ear, nose, throat or mouth structures.
[0243] Such devices, systems and methods may also be used for performing other diagnostic or therapeutic procedures of Eustachian tubes, tympanums and middle ear structures. Examples of such procedures are biopsies, microendoscopy of the Eustachian tube and the middle ear structures, diagnosis and/or treatment of roundwindow ruptures, auditory-ossicle dislocations after tympanoplasty, prothesis dislocation after stapeclotomy, neuroradiologically undetectable liquorrhea caused by otobasal fractures, progressive disorders of the sound—conducting apparatus, Dysplasia of the ear, chronic otitis media mesotympanalis, cholesteatoma, presurgical evaluation of pathologic findings of both the mucosal lining and the ossicular chain, epitympanic retraction pockets of the ear drum, all chronic and recurrent ventilation or drainage disorders of Eustachian tubes etc.
[0244] FIG. 35 shows a perspective view of an embodiment of a guidewire comprising a sensor used for surgical navigation. Guidewire 3400 comprises a sensor 3402 located on the distal region of guidewire 3400 . Sensor 3402 enables guidewire 3400 to be used in conjunction with a suitable surgical navigation system. In one embodiment, sensor 3402 is an electromagnetic sensor used in conjunction with an electromagnetic surgical navigation system such as GE InstaTrak™ 3500 plus system. In one embodiment, guidewire 3400 comprises an anchoring balloon 3404 located on the distal region of guidewire 3400 . Anchoring balloon 3404 is inflated after positioning guidewire 3400 at a target location. Anchoring balloon 3404 anchors guidewire 3400 to adjacent anatomy and prevents accidental repositioning of guidewire 3400 during a diagnostic or therapeutic procedure. Anchoring balloon 3404 may be made from suitable compliant or semi-compliant material such as crosslinked polyethylene or other polyolefins, polyurethane, flexible polyvinylchloride, Nylon etc. In one embodiment, guidewire 3400 comprises a soft distal tip. In another embodiment, guidewire 3400 comprises a curved distal end e.g. a “J” shaped distal end. Sensors similar to sensor 3402 may be present on other diagnostic or therapeutic devices disclosed herein such as balloon catheters etc. Similarly, the devices disclosed herein may comprise other types of sensors or transmitters such as electromagnetic, RF, piezoelectric, magnetic etc. The sensors or transmitters may be in the form of a variety of configurations including but not limited to single coils, multiple coils, antennae etc. The sensors or transmitters may be oriented in a variety of configurations including but not limited to nested, paired, orthogonal to each other, etc.
[0245] FIG. 35A shows an enlarged view of an embodiment of a low profile proximal region of the guidewire in FIG. 35 . The proximal region of guidewire 3400 comprises a distal electrical contact 3406 and a proximal electrical contact 3408 . Distal electrical contact 3406 and proximal electrical contact 3408 are connected to sensor 3402 by conducting wires that run along guidewire 3400 to provide electrical energy to sensor 3402 . Distal electrical contact 3406 and proximal electrical contact 3408 are connected to an external electrical supply by detachable electrodes. Distal electrical contact 3406 and proximal electrical contact 3408 can be made of suitable conducting materials such as stainless steel, silver-palladium alloys, silver-platinum alloys etc. Distal electrical contact 3406 and proximal electrical contact 3408 are separated from each other by a first insulating element 3410 . In one embodiment, guidewire 3400 further comprises a second insulating element 3412 located on the proximal end of guidewire 3400 . A low profile proximal region allows for the introduction of diagnostic or therapeutic devices over guidewire 3400 .
[0246] FIG. 35B shows a perspective view of a method of advancing a diagnostic or therapeutic device over the guidewire in FIG. 35 . In this example, the diagnostic or therapeutic device is a balloon catheter 3414 comprising a shaft 3416 having a balloon 3418 at the distal region of shaft 3416 and a hub 3420 at the proximal end of shaft 3416 . Balloon catheter is advanced into a target anatomical region over the guidewire 3400 . In this example, guidewire 3400 comprises a low profile proximal end so that devices can be introduced in an over-the-wire manner into a target anatomy.
[0247] FIG. 35C shows a perspective view of an embodiment of a combination of a guidewire comprising a sensor having a diagnostic or therapeutic device preloaded on the guidewire. In this example, the diagnostic or therapeutic device is balloon catheter 3414 . The proximal end of guidewire 3400 is connected to an external electrical supply 3422 by conducting wires 3424 . In this example, guidewire 3400 does not have a low profile proximal end so that devices cannot be introduced in an over-the-wire manner into a target anatomy. Thus, balloon catheter 3414 is preloaded on guidewire 3400 by inserting proximal end of balloon catheter 3414 over distal end of guidewire 3400 .
[0248] FIG. 35D shows a perspective view of a second embodiment of a combination of a guidewire comprising a sensor having a diagnostic or therapeutic device preloaded on the guidewire. In this example, the diagnostic or therapeutic device is balloon catheter 3414 . The proximal end of guidewire 3400 is connected by conducting wires 3426 to plug 3428 . Plug 3428 detachably fits into an external power supply 3430 . In this example, guidewire 3400 does not have a low profile proximal end so that devices cannot be introduced in an over-the-wire manner into a target anatomy. Thus, balloon catheter 3414 is preloaded on guidewire 3400 by inserting proximal end of balloon catheter 3414 over distal end of guidewire 3400 .
[0249] One or more flexible regions especially flexible distal regions on the diagnostic or therapeutic devices disclosed herein may comprise bending or deflecting elements. Examples of such bending or deflecting elements are one or more pull wires etc. made of suitable materials such as stainless steel flat wire etc.
[0250] The abovementioned devices and methods may also be used for diagnosing or treating other conditions caused by narrowing or blockage of structures in the ear, nose, throat or mouth such as choanal atresia.
[0251] Various devices described herein such as catheters may comprise one or more lumens such as end-to-end lumens, zipper lumens, rapid exchange lumens, parallel lumen surrounded by a jacket etc.
[0252] It is to be appreciated that the invention has been described hereabove with reference to certain examples or embodiments of the invention but that various additions, deletions, alterations and modifications may be made to those examples and embodiments without departing from the intended spirit and scope of the invention. For example, any element or attribute of one embodiment or example may be incorporated into or used with another embodiment or example, unless to do so would render the embodiment or example unsuitable for its intended use. All reasonable additions, deletions, modifications and alterations are to be considered equivalents of the described examples and embodiments and are to be included within the scope of the following claims. | Sinusitis, mucocysts, tumors, infections, hearing disorders, choanal atresia, fractures and other disorders of the paranasal sinuses, Eustachian tubes, Lachrymal ducts and other ear, nose, throat and mouth structures are diagnosed and/or treated using minimally invasive approaches and, in many cases, flexible catheters as opposed to instruments having rigid shafts. Various diagnostic procedures and devices are used to perform imaging studies, mucus flow studies, air/gas flow studies, anatomic dimension studies and endoscopic studies. Access and occluding devices may be used to facilitate insertion of working devices such asendoscopes, wires, probes, needles, catheters, balloon catheters, dilation catheters, dilators, balloons, tissue cutting or remodeling devices, suction or irrigation devices, imaging devices, sizing devices, biopsy devices, image-guided devices containing sensors or transmitters, electrosurgical devices, energy emitting devices, devices for injecting diagnostic or therapeutic agents, devices for implanting devices such as stents, substance eluting or delivering devices and implants, etc. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of pending U.S. application Ser. No. 13/768,534, filed on Feb. 15, 2013, which is a continuation-in-part of application Ser. No. 12/436,562, filed May 6, 2009 (now U.S. Pat. No. 8,493,021), which is a continuation-in-part of application Ser. No. 12/330,875, filed Dec. 9, 2008, which claims the benefit of provisional patent application 61/018,715, filed Jan. 3, 2008, all entitled METHOD AND APPARATUS FOR PROVIDING SUPPLEMENTAL POWER TO AN ENGINE.
FIELD
The present invention relates to a portable power source for a motor vehicle and, more particularly, to a method and apparatus to provide supplemental power to start internal combustion and turbine engines.
BACKGROUND
Internal combustion and turbine engines require a power source to start. Commonly, this power source is in the form of a battery, which provides power to a starter motor, which in turn drives the engine. The crankshaft of the engine is rotated by the starter motor at a speed sufficient to start the engine. If the battery goes dead or otherwise lacks sufficient power for the starter motor to drive the engine, the engine won't start. Environmental factors, such as temperature, affect the output of the battery and power required to rotate the engine.
If the battery lacks sufficient power to start the engine, a supplemental power source is necessary to jump start the engine. Typically, jumper cables are used to connect the battery of one vehicle to the dead battery of another vehicle needing to be jumped. The batteries are connected in parallel using heavy cables (jumper cables) which are connected to the terminals of the batteries using conductive clamps.
Several potential problems arise from the use of conventional jumper cables. Batteries in motor vehicles are capable of producing from 2,500 to more than 45,000 watts of power. If the batteries are cross-connected or the clamps inadvertently contact each other when one end of the jumper cables is connected to a battery, sparking can occur resulting in damage to the battery, the electrical system of the vehicle, and injury to the user of the jumper cables. If the jumper cables are not properly connected, there is a potential for the batteries exploding and fire, which may result in injury to those in proximity to the vehicle being jumped. Furthermore, the user is not given any indication as to the reason the battery is dead, which may only cause additional problems when trying to jump start the dead battery.
SUMMARY
The present invention provides an apparatus and method for temporarily delivering supplemental power to the electrical system of a vehicle. The apparatus and method performs real-time monitoring of all system parameters to increase the safety and effectiveness of the unit's operation while providing additional parametric and diagnostic information obtained before, during and after the vehicle starting operation.
The present invention monitors the voltage of the battery of the vehicle to be jump started and the current delivered by the jump starter batteries and capacitors to determine if a proper connection has been established and to provide fault monitoring. For safety purposes, only if the proper polarity is detected can the system operate. The voltage is monitored to determine open circuit, disconnected conductive clamps, shunt cable fault, and solenoid fault conditions. The current through the shunt cable is monitored to determine if there is a battery explosion risk, and for excessive current conditions presenting an overheating condition, which may result in fire. The system includes one or more internal batteries and capacitors to provide the power to the battery of the vehicle to be jump started. Once the vehicle is started, the vehicle's electrical system may recharge the batteries and capacitors before the unit automatically electrically disconnects from the vehicle's battery.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a functional block diagram of the portable power source of the present invention.
FIG. 2 (divided into FIGS. 2A, 2B, 2C and 2D ) is a schematic of the portable power source, control circuit and sensors of the present invention.
FIGS. 3-8 are flow charts of the processing steps of the portable power source of the present invention.
FIG. 9 is a flow chart of the interrupt service routine of the system of the portable power source of the present invention.
DESCRIPTION
As required, detailed embodiments of the present invention are disclosed herein. However, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for the claims and/or as a representative basis for teaching one skilled in the art to variously employ the present invention.
Moreover, except where otherwise expressly indicated, all numerical quantities in this description and in the claims are to be understood as modified by the word “about” in describing the broader scope of this invention. Practice within the numerical limits stated is generally preferred. Also, unless expressly stated to the contrary, the description of a group or class of materials as suitable or preferred for a given purpose in connection with the invention implies that mixtures or combinations of any two or more members of the group or class may be equally suitable or preferred.
Referring initially to FIG. 1 , the portable supplemental power source (jump starter) of the present invention is generally indicated by reference numeral 10 . Jump starter 10 includes a programmable microprocessor 12 which receives inputs 14 and produces informational outputs 16 and control outputs 18 . Microprocessor 12 provides flexibility to the system 10 to allow updates to the functionality and system parameters without changing the hardware. In the preferred embodiment, an 8-bit microprocessor with 64K bytes of programmable flash memory is used to control the system 10 . One such microprocessor is the ATmega644P available from Atmel Corporation. The microprocessor 12 may be programmed via an internal connector 90 , or an external connector 92 (see FIG. 2 ). It should be understood that other programming ports may be included are not limited to the two shown in the figure.
A capacitor voltage sensor 49 monitors the voltage level of one or more capacitor 21 . The capacitors 21 may include energy storage modules containing six or more ultracapacitor cells, for example. The capacitor modules 21 may be connected in series to obtain higher operating voltages or in parallel to provide additional energy storage. One such capacitor module is the Boostcap Energy Storage Module available from Maxwell Technologies, Inc.
A battery voltage sensor 20 monitors the voltage level of one or more jump starter batteries 22 . A reverse voltage sensor 24 monitors the polarity of the jumper cables on line 26 which are connected to the vehicle's electrical system 28 . A vehicle voltage sensor 30 monitors the voltage on line 37 (voltage of the vehicle). When the contacts are open, the solenoid voltage sensor 32 input to microprocessor 12 is used to measure the voltage of the jump starter capacitors 21 and batteries 22 , which may be configured for various jump starter voltages. When the contacts are closed, the voltage difference between the capacitors 21 and batteries 22 , and the contact relay 34 is used to measure the voltage drop across a temperature-and-resistance calibrated 00 AWG shunt cable 36 in order to calculate the current being delivered by the jump starter capacitors 21 and batteries 22 to the vehicle's electrical system 28 . Although the present invention is disclosed and described as temporarily connected to a vehicle, it should be understood that it is equally applicable to a stationary engine. Additionally, the connection method to the electrical system or batteries of the engine to be started is not important and may include conductive clamps, NATO connectors, or may be permanently hardwired to the system, for example.
A battery temperature sensor 38 monitors the temperature of the jump starter's batteries 22 to detect overheating due to excess current draw from the batteries during jump starting. A shunt cable temperature sensor 40 monitors the temperature of the 00 AWG shunt cable 36 in order to compensate for resistance changes of the shunt cable due to the high current passing through the shunt cable 36 and to detect overheating conditions. The unit 10 also includes automatic 42 and manual 44 pushbutton inputs to accept user input to select either automatic or manual operation.
The temperature of 00 AWG shunt cable 37 may also be monitored by a temperature sensor or thermal switch 41 . As long as the temperature of the cable 37 is below a predetermined limit, the input on line 58 is passed through sensor 41 to line 59 to enable the contact relay 34 as controlled by system microcontroller 12 . If the temperature of the cable 37 exceeds a predetermined limit, then the temperature sensor 41 presents an open circuit to control line 58 to disable contact relay 34 and not allow power to be applied to the vehicle 28 . It should be understood that the temperature sensor 41 may be coupled to cable 36 , 37 or any other cable that may become overheated. Additional temperature sensors may be used to provide additional protection of the system from overheating.
A capacitor temperature sensor 47 monitors the temperature of the jump starter capacitors 21 to detect overheating due to excess current draw from the capacitors during jump starting.
The microprocessor 12 includes several outputs 16 to provide information to the user and to control the application of power to the vehicle to be jump started. An LCD display 46 may be used to display user instructions, error messages, and real-time sensor data during operation of the jump starter 10 . A reverse voltage LED 48 is illuminated when the microprocessor 12 determines that a reverse voltage jumper cable voltage is detected by reverse voltage sensor 24 . An auto mode LED 50 is illuminated when the automatic mode pushbutton 42 is depressed. A manual mode LED 52 is illuminated when the manual mode pushbutton 44 is depressed. If the voltage level of the jump starter batteries 22 drop below a value of twenty percent of the normal level, a charge battery LED 54 is illuminated. The charge battery LED 54 remains illuminated until the batteries 22 are charged to a minimum state of charge such as fifty percent, for example. A fault LED 56 is turned on anytime the microprocessor 12 detects any operational, sensor or internal fault. An audible warning may also be provided 70 . The fault LED 56 remains illuminated until the fault condition is cleared.
A contact relay control output 58 operates the contact relay 34 through temperature sensor 41 . When the jump starter operation has been successfully initiated, the contact relay 34 is closed and the jump starter capacitors 21 and batteries 22 are connected to the starter system or batteries of the vehicle to be started 28 . The contact relay 34 is opened when a successful start cycle has been completed, a start fault has occurred or the operator interrupts the jump starter cycle. An optional key pad 72 may be included and used for entry of a passcode to operate the unit 10 , or to identify one or more users of the system which may be stored to track user operation. For example, if two different users operate the unit 10 and error conditions are recorded for one of the users, this information may be used to identify training issues that need to be addressed.
Referring to FIGS. 2A, 2B, 2C, 2D and 3-8 , when the jump starter 10 is initially powered on 200 , the microcontroller 12 initializes the hardware, reads all system parameters and variables, and initializes the interrupt service routine 202 (See FIG. 8 ). All stored performance history is read from the onboard, non-volatile memory 204 and a start message is displayed 206 on the LCD display 46 . The history is saved for diagnostic, unit use and safety purposes. The microcontroller 12 then performs a system self-test operation 208 where the LCD 46 , all LEDs 48 , 50 , 52 , 54 and 56 , all sensors 20 , 24 , 30 , 32 , 38 , 40 , the push buttons 42 and 44 , and the system batteries 22 are tested and their status displayed 208 on the LCD 46 . If a fault is detected 400 , an error message is displayed 402 and system operation is halted.
Once the initialization and self-test operations are completed, the system starts into a main processing loop 210 . An interrupt service routine (“ISR”) 500 ( FIG. 9 ) is also started which constantly monitors all input sensor values and user input buttons. The ISR 500 is periodically called by the microcontroller 502 . A check is made to determine if the serial input buffer flag is set 504 . If the flag is set 504 , then configuration information is read and flags set or cleared 506 . If the output flag is set 508 , the information is transmitted to an external PC and the output buffer flag is cleared 510 . Next, all input parameters are read 512 , and a moving average is calculated for each parameter 514 . If the PC remote flag is set 516 , all parameters and statuses are copied to the output buffer 518 and the output buffer flag is set 520 . The manual mode AC starting current profile is calculated 522 , all event timer counts are incremented 524 , and the status of the automatic 42 and manual 44 pushbuttons is monitored and set 526 . All calculations, timer counts, and status indications (flags) are stored in the internal memory of the microprocessor 12 .
At the start of the main process loop 210 , the flags are checked 404 beginning with the shunt calibration flag 406 . If the shunt calibration flag is set 406 , the starter contact relay 34 is closed 408 . The temperature of the shunt cable is measured 410 and the voltage drop across the shunt cable is read 412 . The temperature of the shunt cable is measured a second time and averaged with the previous reading 414 . The shunt resistance is then calculated and saved 416 and the shunt calibration flag is cleared 418 .
Next, if the flag to upload data to an external PC is set 420 , the information is copied to the output buffer 422 , the output buffer ready flag is set 424 , and the upload data flag is cleared 426 . If the download data from PC flag is set 428 , data is copied from the input buffer 430 , and the download data flag is cleared 432 .
If the PC remote control flag is set 434 , the remote control status flag is toggled 436 . If the flag is true, the unit 10 can be controlled remotely by a PC or locally by the buttons. If the flag is false, the unit can only be controlled locally.
If the system does not detect a battery charging voltage 212 , once jumper cables 60 have been manually connected to the vehicle to be started 28 , the voltage is measured by the reverse voltage sensor 24 to determine if the cables have been properly connected to the vehicle 214 . If the voltage measured is significantly less than the voltage of the jump starter capacitors 21 and batteries 22 , then a reverse polarity connection of the jumper cables to the vehicle is determined and an error flag is set and the event saved in non-volatile memory 216 . A “Reverse Polarity” error message is displayed 218 on the LCD 46 , and the reverse voltage LED 48 is illuminated 216 . Any further jump starter action by the operator is ignored until the reverse polarity condition is corrected 220 , at which point processing returns to the start of the main processing loop 210 .
If the jumper cables 60 are not reverse connected 214 , then the state of charge of the capacitors 21 and batteries 22 is determined 222 . If the voltage level of the system batteries 22 measured by the voltage sensor 30 is equal to a state of charge of eighty percent or more below a fully charged voltage level 222 , an error flag is set and the event recorded in memory 224 . The charge battery LED 54 is illuminated and the LCD 46 displays a “Charge Battery” message 225 . The system stays in this condition, which prohibits any further jump starter action by the operator until a charging voltage is detected 226 , which is great enough to indicate that a battery charger (not shown) has been connected to the batteries 22 .
If the system has detected a battery charger voltage 212 , a “Battery Charging” message is displayed 228 on the LCD 46 , and the charge LED 54 is illuminated. The voltage profile of the battery 22 is monitored to determine if the charge is complete 230 . A completed charge is determined by monitoring the charging voltage rise to a threshold value then decrease by a predetermined percentage. This voltage peaking and subsequent fall-off is a characteristic of the battery chemistry indicating that the battery has reached its maximum charge capacity. Once the charging has reached a minimum charged level or is completed 230 , the processing returns to the beginning of the main processing loop 210 . The jump starter batteries 22 only need to reach a 50% charge in order for the system to attempt to start the vehicle.
If the battery or capacitor temperature measured by sensors 38 and 47 rises above a maximum safe threshold 232 , an error flag is set and the event recorded in non-volatile memory 234 . An error message “Battery Over Temperature” or “Capacitor Over Temperature” is displayed 236 on the LCD 46 and the Fault LED 56 is illuminated. The system prevents any further operation until the battery and/or capacitor temperature falls below a safe level 238 . Once a safe temperature is reached, processing returns to a ready state at the beginning of the main processing loop 210 .
If the voltage of one or more of the capacitors measured by the capacitor voltage sensor 49 exceeds a predetermined limit 239 , such as 2.8 volts, for example, an error flag is set and the event recorded in non-volatile memory 241 . An error message “Capacitor Over Voltage” is displayed 243 and the fault LED 56 is illuminated. Processing then returns to the main processing loop 210 .
If the temperature of the shunt cable 36 rises above a safe threshold temperature 240 , an error flag is set and the event recorded in memory 242 . An error message “Cable over Temperature” is displayed 244 on the LCD 46 and the Fault LED 56 is illuminated. The system prevents any further operation until the shunt cable temperature falls below a minimum safe temperature 246 . Once a safe temperature is reached, the system returns to a ready state at the beginning of the main processing loop 210 .
Next, the system checks the status of the automatic 42 and manual 44 push buttons. If neither button has been pushed 248 , a “Ready” message is displayed 250 on the LCD 46 and processing returns to the main processing loop 210 . When no error conditions are detected and no user inputs are being processed, the system remains in the ready mode, and displays a “Ready” text message on the LCD 46 . Other information such as the selected jump starter voltage, the percentage change of the batteries 22 , the temperature of the batteries, and the vehicle voltage, for example, may also be displayed on LCD 46 .
If one of the push buttons 42 or 44 has been selected, the system will compare the operator-configured starter voltage against the voltage of the vehicle to be started 28 . The jump starter 10 may be configured for 12, 18, 24, 30, 36, 42 or 48 volts, for example, using a selector jumper 55 . For example, if the batteries 23 are both 12-volt batteries, the system may be configured for 12- or 24-volt operation. For example, if jumper 27 is placed across terminals 31 , the 24-volt configuration may be selected. If jumper 29 is placed across terminals 31 , the 12-volt configuration may be selected. If the batteries 23 are 12-volt batteries and a battery 25 is a 6-volt battery, 18- or 30-volt configurations may be provided. For example, if jumper 27 is placed across terminals 31 , the 30-volt configuration may be selected. If jumper 29 is placed across terminals 31 , the 18-volt configuration may be selected. It should be understood that two or more batteries of the same or different voltage levels may be used to meet the voltage requirements of the vehicle to be started. If the difference between the voltage selected and the voltage measured is not within a predetermined range and tolerance 252 , a “Wrong Selector Volts” message is displayed 254 on the LCD 46 and further operation is prohibited until the correct voltage is selected 256 at which point processing returns to the main processing loop 210 .
If the selected voltage is within the correct range 252 , then the system determines which button was selected 258 . If the Auto button 42 was pushed, a ninety-second count down timer is started and displayed 260 on the LCD 46 . During this time the system monitors the vehicle voltage 262 . If the system does not detect a voltage drop 264 within 90 seconds 265 , the automatic operation is cancelled and processing returns to the main processing loop 210 . The automatic operation may also be interrupted and canceled by pushing the auto button 267 . If the vehicle voltage drops by twenty percent or more from the initially measured voltage 264 , then the vehicle's starter motor is engaged and is trying to start the vehicle. If the maximum number of start attempts has not been exceeded 266 , the contact relay 34 is closed and the contact relay on timer is started 268 , connecting the jump starter's capacitors 21 and batteries 22 to the vehicle's starting system 28 . The start cycle counter is incremented 270 , a “Jump Starter On” message is displayed 272 along with the average current being drawn, and the Auto Mode LED 50 is illuminated. If the relay on timer expires indicating that the relay 34 has been closed for ninety seconds without a start complete event, the relay 34 is automatically opened by the system to reduce the probability of overheating any component in the jump starter or vehicle.
The system monitors all input sensors 14 and the current status of the jump starter for possible fault conditions. Upon detection of any fault condition, the system will open the contact relay 34 (if closed), and display a message indicating that a fault has occurred, and what action, if any, should be taken by the operator.
If the battery temperature exceeds a maximum limit 274 , a battery temperature error count is incremented 276 . The contact relay 34 is opened, a “Battery Temp” error message and temperature is displayed 278 on the LCD 46 and the fault LED 56 is illuminated. Processing returns to the main processing loop 210 .
If the shunt cable temperature exceeds a maximum limit 280 , a cable temperature error count is incremented 282 . The contact relay 34 is opened, a “Cable Temp” error message and temperature is displayed 278 on the LCD 46 and the fault LED 56 is illuminated. Processing returns to the main processing loop 210 .
If the system detects a geometric rise in the starting current 284 during the first 16 seconds after the contact relay 34 is closed, a current doubling error count is incremented 286 , a “Battery Explosion” error message is displayed 288 on the LCD 46 , the contact relay 34 is opened and the fault LED 56 is illuminated 290 . The system may be returned to the ready mode if the Automatic button 42 is pressed by the operator 292 , or automatically after five minutes 294 .
If no current flow is detected by the system 296 indicating that there is an open circuit within the system, an open circuit error count is incremented 298 , an “Open Circuit” error message is displayed 300 on the LCD 46 , the contact relay 34 is opened and the fault LED 56 is illuminated 290 . The system may be returned to the ready mode if the Automatic button 42 is pressed by the operator 292 , or automatically after five minutes 294 .
If the system detects an increase in the difference between the measured jump starter battery voltage 20 and the voltage measured 30 across the contact relay 34 indicating that one of the jump starter cables has been disconnected 302 from the vehicle's battery or starter system 28 then a jumper cable unplugged error count is incremented 304 , a “Jumper Cable Unplugged” error message is displayed 306 on the LCD 46 , the contact relay 34 is opened and the fault LED 56 is illuminated 290 . The system may be returned to the ready mode if the Automatic button 42 is pressed by the operator 292 , or automatically after five minutes 294 .
During the jump starting process if the current measured across the shunt cable 36 is greater than a preset maximum current such as 1400 amps for a short period of time such as 500 ms 308 , the over max current error count is incremented 310 , an “Over MAX Starting Current” error message is displayed 312 on LCD 46 , the contact relay 34 is opened and the fault LED 56 is illuminated 290 . The current across the shunt cable 36 is also measured to determine if it exceeds a predetermined current such as 1000 amps for more than a predetermined period of time such as 15 seconds 314 . If this over current condition is determined, an over high current error count is incremented 316 , an “Over High Crank Amps” error message is displayed 318 on the LCD 46 , the contact relay 34 is opened and the fault LED 56 is illuminated 290 . The system may be returned to the ready mode if the Automatic button 42 is pressed by the operator 292 , or automatically after five minutes 294 .
If the system detects a decrease in the jump starter battery voltage 20 , but does not detect an appreciable current flow through the jump starter, a shunt cable 36 failure is indicated 320 . The shunt cable 36 is a precisely measured and calibrated 00 AWG wire, the temperature of which is monitored 40 and used to calculate the resistance across the length of the cable 36 .
The voltage drop across the cable 36 is also measured to calculate the current through the shunt cable 36 using Ohm's Law. If the shunt cable 36 fails, the system cannot reliably measure the starting current which would present a safety hazard.
If the system detects a shunt cable failure 320 , a current shunt error count is incremented 322 , a “Current Shunt Failure” error message is displayed 324 on the LCD 46 , the contact relay 34 is opened and the fault LED 56 is illuminated 290 . The system may be returned to the ready mode if the Automatic button 42 is pressed by the operator 292 , or automatically after five minutes 294 .
If the system detects a great difference between the vehicle's voltage 30 and the contact relay 34 voltage 326 , the contact relay 34 may have failed indicating an over high starter current condition. A contact relay failure count is incremented 328 , a “Contact Relay Error” message is displayed 330 on the LCD 46 , the contact relay 34 is opened and the fault LED 56 is illuminated 290 . The system may be returned to the ready mode if the Automatic button 42 is pressed by the operator 292 , or automatically after five minutes 294 .
If manual mode is selected 258 , “Manual” is displayed 332 on the LCD 46 , the system will prompt the operator to press the manual button 44 again. If the manual button 44 is pressed a second time 334 , then the system checks the number of start attempts 266 . If the maximum number of start attempts has been exceeded 266 , an over start attempt error count is incremented 336 , a “Cool Down Unit” message is displayed 338 on the LCD 46 , and the system waits for five minutes for the system to cool 340 . Once the cool down time has expired, processing returns to the main processing loop 210 . If the total start attempts have not exceeded the limit 266 , the processing continues at block 268 as described above.
If in auto mode and the starting current decreases by 20% from the maximum measured current 342 , then the start cycle is complete. A decrease in the starting current indicates that the vehicle has started and its alternator is now generating its own current reducing the demand from the jump starter batteries 22 . If the starting current is below the threshold 342 , a “Start Cycle Complete” message is displayed 344 on LCD 46 , and the contact relay is opened 346 . This message remains displayed until the operator presses the Auto button 292 , or if there is no user activity for five minutes 294 , after which the system returns to the main processing loop 210 .
If in manual mode, the jump starter 10 may be used when the battery voltage of the vehicle is below 10 volts, or if the vehicle's battery is not connected. In the situation where the vehicle's battery is present but has a voltage of less than 10 volts, the jump starter will start to charge the vehicle's battery before any starting operation begins. If the vehicle's battery is extremely low or completely dead, once the contactor is closed, the jump starter's batteries will start to charge the batteries. The current will rise sharply and then start to decrease, but this does not indicate that a start attempt has been made or that the vehicle's starter motor has been cranked. The algorithm looks for this initial increase and then decrease in the delivered current and then waits for a minimum of three alternating current cycles indicating that the vehicle's starter has been engaged. Due to the compression/decompression cycles of the pistons, the starting current will rise and fall in a generally sinusoidal pattern. The algorithm looks for this so that it knows that the vehicle's starter motor has been activated. Once this alternating current cycle has been detected, if the current then decreases by approximately twenty percent and remains low, this indicates a start complete, the contactor is opened, the start complete message is displayed and then the system waits for the Auto button to be pushed or the 5 minute timeout.
If the vehicle's battery holds the charge, then the starting cycle in manual mode is the same as described above for automatic mode. If the battery does not hold the charge or if no battery is present, the system waits until the vehicle's starter motor is engaged. Once the vehicle's starter motor is engaged and the engine is turning over, the system 10 monitors the jump starter current flow. As the engine turns over the jump starter's current increases and decreases with the compression stroke of the engine's pistons. During a piston's compression cycle, the current from the jump starter's batteries 22 increases due to the increased power demand of the starter motor. During a piston's decompression cycle, the current flow decreases due to the decreased power demand of the starter motor. This current increase and decrease is generally sinusoidal which is recognized by the system.
Once the system has detected three more sinusoidal current flow cycles, the same 20% decrease threshold in current as set forth above for the automatic mode determination, may be used to determine when the vehicle's engine has started 348 . If the engine has started, the “Start Cycle Complete” message is displayed 344 on the LCD 46 and the contact relay opened 346 .
If the engine has not been started 348 , the system next checks the relay closed time. If the maximum time set for the contact relay to be closed has expired 350 , a “Maximum Starter On” message is displayed 352 on the LCD 46 and the contact relay is opened 346 .
If the contact relay closed time has not expired, the system checks for a cycle halt flag. Any cycle may be interrupted by the Auto button being pressed by the operator. If the Auto button is pressed 354 , a “Start Cycle Halted” message is displayed 356 on the LCD 46 , and the contact relay opened 346 .
At the completion of a start cycle the jump starter 10 has opened the contact relay 34 and the message “Start complete” is displayed 46 , and the starting current is displayed for diagnostic assessment of the vehicle's starting system. At this time the voltage of the vehicle 28 is monitored. Normal vehicle charging voltages fall within certain ranges for 12, 18, 24, 30, 36, 42 and 48 volts systems. The jump starter displays the running vehicle's voltage and makes an assessment to determine if the vehicle's generated voltage is actually great enough to charge the vehicle's battery. If the voltage is below a threshold for charging the vehicle's battery, the jump starter displays “Vehicle Not Charging” message and shows the measured voltage. If the vehicle's generated voltage is great enough to charge the vehicle's battery, the jump starter displays “Vehicle Charging” showing a working vehicle charging system and displays the vehicle charging voltage.
Referring to FIGS. 1 and 2 , a diode 35 may be connected across the contact 34 to charge the capacitors 21 and jump starter batteries 22 from the vehicle charging system 28 . The charging system of the vehicle may be used to charge the capacitors 21 and jump starter batteries 22 . Whenever the vehicle has a working charging system this will occur as long as the cables are connected to the vehicle. This allows the capacitors 21 and jump starter batteries 22 to be fully recharged in about 1 to 5 minutes and can therefore start many vehicles in a row without becoming discharged. Even in situations in which the jump starter batteries 22 may be discharged to an extent that they alone may not be able to provide the necessary power to start a vehicle, the capacitors 21 may be rapidly recharged to start many vehicles in a row. This is very useful when starting fleets of vehicles with dead batteries.
It is to be understood that while certain forms of this invention have been illustrated and described, it is not limited thereto, except in so far as such limitations are included in the following claims and allowable equivalents thereof. | An apparatus provides supplemental power to an engine. The apparatus includes a pair of conductive leads for connecting the supplemental power to an engine electrical system, one or more batteries connected in parallel with one or more capacitors, a relay connected to the conductive leads, a shunt cable connecting the batteries and capacitors to the relay and a switch for controlling the relay to selectively apply electrical power to the engine electrical system. The apparatus includes safety features to reduce the risk of injury to the operator and damage to the apparatus and/or engine electrical system. | 7 |
FIELD OF THE INVENTION
This invention relates to cobalt-chromium dental alloys. More particularly, this invention relates to cobalt-chromium alloys containing ruthenium and aluminum, such that the resulting alloys exhibit outstanding physical, thermal and oxidation properties thereby rendering such alloys suitable for use in porcelain-fused-to-metal restorations without the need for a bonding agent in the fabrication of such restorations.
BACKGROUND OF THE INVENTION
Numerous criteria must be met by an alloy to be used in the fabrication of prosthetic dental appliances such as procelain-veneered fixed bridgework and crowns. For example, the alloy must be tissue tolerant, tarnish resistant, corrosion resistant and non-toxic.
In addition, the alloy should form a protective and adherent oxide on its surface during torch melting and during the porcelain-firing cycle which does not grow dramatically in thickness. The oxides formed must be compatible with the porcelain; otherwise, they may affect the thermal expansion of the interfacial porcelain. Still further, the oxides should not discolor the porcelain. Most preferably, the oxide should be able to bond the porcelain to the alloy without the need for a separate bonding agent.
The alloy must also have a coefficient of thermal expansion slightly higher than that of the porcelains currently available on the market thereby placing the porcelain under compression and minimizing the stresses formed at the interface.
The alloy also should be shape-stable with porcelain application, possess adequate strength for function, produce an acceptable fit and be solderable. Finally, it should possess a high modulus of elasticity, high-yield strength and hardness and be easily cast, ground and polished using techniques conventionally employed in dental laboratories.
The criteria which govern the selection of a suitable alloy for use in the preparation of porcelain-veneered fixed bridgework and crowns are quite different from the criteria involved in selecting alloys for use in the fabrication of partial dentures which generally are not used in conjunction with porcelain. These criteria, to a large extent, have heretofore been met by alloys having a high precious metal content. Such alloys have contained gold, platinum, palladium, silver, indium, tin, gallium, zinc, and the like, and trace metals. Formulations of alloys of this type are set forth in U.S. Pat. Nos. 1,283,264, 3,413,723, 3,667,936, 3,767,391, 3,819,366, 3,981,723 and 4,007,040.
With the ever increasing and fluctuating cost of precious metals and the superior physical properties and technological advantages offered by nickel-chrome-base alloys, such alloys have become widely used as an alternative to precious alloys in dentistry. These alloys generally utilize tin, gallium and the like to impart specific physical characteristics. Typical of such alloys are those described in U.S. Pat. Nos. 2,089,587, 3,304,177, 3,464,817, 3,749,570 and 3,914,867.
Currently, there is growing concern about nickel being an allergen and beryllium being a toxic element. Although much data are still needed, there is an apparent need for an alloy which contains neither nickel nor beryllium, has a low precious metal content and yet meets the above criteria.
A number of cobalt-chromium base alloys with and without nickel and/or beryllium have heretofore been employed in dentistry for the fabrication of removable partials, crowns and bridgework. Typical of such alloys are those described in U.S. Pat. Nos. 3,756,809, 3,802,875, 3,802,934 and 3,837,838. However, their compositions and physical and thermal properties have limited their use for porcelain-veneered crown and bridgework.
Cobalt-chromium based alloys having a variety of compositions and said to be useful for porcelain-fused-to-metal restorations have been disclosed in U.S. Pat. Nos. 4,229,215, 4,253,869, 4,255,190 and 4,263,045. Of these, U.S. Pat. Nos. 4,253,869 and 4,255,190 describe alloys including cobalt, chromium and ruthenium. None of the alloys disclosed in these patents, however, includes aluminum or aluminum/yttrium, which, in accordance with the present invention, has been found to significantly improve the oxide formed on the alloy and the reactivity of the alloy with the melting crucible and the casting investment.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an alloy with a low precious metal content which exhibits many of the properties of metal alloys having a high precious metal content heretofore considered desirable in the fabrication of porcelain-veneered fixed bridgework and crowns.
It is another object of the present invention to provide an alloy free of nickel and/or beryllium.
These as well as other objects and advantages are accomplished by the present invention which provides chromium-cobalt alloys containing ruthenium and aluminum which are significantly different from prior chromium-cobalt alloys heretofore employed in the fabrication of prosthetic dental appliances. The chromium-cobalt alloys of the present invention exhibit melting characteristics enabling the use of standard natural gas/oxygen torches conventionally used in dental laboratories. Moreover, the alloys of the present invention form greatly improved oxides during torch melting and the procelain firing process, which oxides bond the alloy to the porcelain without the need for a separate bonding agent. Accordingly, the alloys of the present invention can be successfully employed in the fabrication of porcelain-veneered fixed bridgework and crowns in lieu of alloys having a high precious metal content and alloys having nickel and/or beryllium heretofore employed.
The cobalt-chromium alloys of the present invention consist essentially of about:
______________________________________Element Weight Percent______________________________________Cobalt 40-60Chromium 20-30Ruthenium 5-15Aluminum 1-4Yttrium 0-0.15Tungsten 0-15Molybdenum 0-6.5Niobium 0-3.0Zirconium 0-0.25Manganese 0-1.5______________________________________
wherein the sum of the constituents equals 100% and the sum of the tungsten and molybdenum constituents minus the sum of the ruthenium, niobium and zirconium constituents is less than about 5%. These alloys exhibit outstanding physical and chemical properties, including the formation of a tenacious bond with porcelain without the need for a separate bonding agent, and can be used advantageously as a substitute for alloys having a high proportion of precious metals as well as for nickel-chromium-based alloys in the fabrication of porcelain-veneered fixed bridgework and crowns.
Preferred formulations of alloys following the teachings of the invention are given in Table I.
TABLE I______________________________________ Weight PercentElement 1 2 3 4______________________________________Co 54.85 53 55 60Cr 25 23 25 25Ru 5 10 5 5Al 2.9 3.9 2.9 3.9Y 0.1 0.1 0.1 0.1W 10 10 10 --Mo -- -- -- 5Nb 2 -- 2 --Zr 0.15 -- -- --Mn -- -- -- 1.0______________________________________
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The cobalt-chromium alloys of the present invention are especially suited for use in the fabrication of prosthetic dental appliances since the cobalt in the alloy imparts characteristics to the alloy which closely correspond to those of alloys having a high precious metal content, especially the coefficient of thermal expansion which is quite close to that of gold. The chromium in the alloy provides enhanced corrosion and tarnish resistance. Chromium in amounts of from about 20% to 30% acts as a solid solution strengthener and provides a convenient means of adjusting the thermal expansion characteristics of the alloy to conform to the variations encountered upon use of different commercial porcelains.
The incorporation of aluminum or aluminum/yttrium in the alloy has been found to be critical in meeting the various criteria imposed on alloys which are useful in the preparation of porcelain-fused-to-metal restorations. In particular, when aluminum or aluminum/yttrium is included in the alloy, it has been found that porcelain readily and firmly bonds to the alloy without the need for a separate bonding agent. Also, the aluminum or aluminum/yttrium lowers the casting temperature and enhances the oxidation resistance of the alloy. This increased oxidation resistance helps prevent the formation of a thick oxide layer on the casting during the porcelain application process. This is important because thick oxide layers are fragile and impair the strength of the porcelain-metal bond in porcelain-fused-to-metal dental restorations.
The alloys of the present invention also have been found to be relatively unreactive with the crucible during torch melting. The alloys leave a thin slag which can be lifted up easily. It is believed that the aluminum, with the aid of yttrium, when used, leads to this behavior.
Further, the alloys of the invention produce castings having cleaner surfaces than those achieved with prior cobalt-chromium alloys containing ruthenium. This improvement is believed to result from the fact that the alloy reacts less with the investment and thus, after the investment is removed, the surface of the casting is both smoother and more characteristic of the metal of the alloy, rather than of a reaction product of the alloy with the investment. Again, it is believed that the aluminum, plus to some extent the yttrium, when used, leads to this result.
Also, the oxide formed on the alloys of the invention during degassing and during the porcelain firing process has a better color than the oxide formed on prior art cobalt-chromium alloys. In particular, the oxide formed during degassing is light grey in color and this color does not darken during the application of the porcelain. In contrast, prior art cobalt-chromium alloys form, during degassing, a greenish oxide which darkens during the subsequent porcelain firing process. Again, it is believed that the aluminum or aluminum/yttrium leads to this improvement.
To adjust the thermal expansion of the alloy varying amounts of niobium and tungsten/molybdenum are used. Alternatively, tantalum and vanadium can be used instead of tungsten and molybdenum. Ruthenium also has an effect on the expansion behavior. All of these elements lower the coefficient of thermal expansion of the alloy.
The ruthenium, niobium and zirconium in the alloy serve to make the alloy more ductile. Tungsten and molybdenum, however, as well as chromium, embrittle the alloy. It has been found that alloys having a suitable ductility for porcelain-fused-to-metal restorations are achieved for chromium concentrations in the range of about 20 to about 30% when the sum of the tungsten and molybdenum concentrations minus the sum of the ruthenium, niobium and zirconium concentrations is kept below about 5%. Further, a balance between the amounts of ruthenium, niobium and zirconium on one hand and aluminum or aluminum/yttrium on the other hand must be maintained. This is so because it has been found that aluminum or aluminum/yttrium tends to lessen the improvement in ductitily achieved through addition of ruthenium, niobium and zirconium. Specifically, it has been found that the aluminum concentration must be kept below about 4% and the yttrium concentration below about 0.15%.
The alloys of the present invention can be prepared by conventional alloying techniques. If desired, alloying can be done in air, under vacuum or by employing a blanket of an inert gas such as argon. The latter precautions, although preferred, are not considered essential. Generally, the major alloy constituents are melted first, such as through use of an induction furnace, taking care to maintain a homogeneous distribution of chromium in the melt by overcoming its tendency to float to the surface. After the cobalt and chromium have been melted and are well dispersed, tungsten, when used, can be added. Thereafter, the remaining alloy constituents can be added in either elemental form or as a preformed alloy with cobalt or chromium. Once the alloy melt is prepared and ingots cast therefrom, the remelting of the alloy ingot may be accomplished using a standard natural gas/oxygen torch or induction melting equipment.
The alloys of the present invention can be used instead of alloys having a high proportion of precious metal or alloys based on nickel and chromium without requiring any significant changes in technique other than as presently practiced in a dental laboratory. The castings obtained with the alloys of the present invention exhibit smooth non-porous surfaces. The absence of nickel and beryllium precludes the need for any special handling precautions.
The following examples further illustrate the criticalities of the alloy composition of the present invention. Unless otherwise specified, all percentages and parts are by weight.
EXAMPLES 1-12
The alloy compositions set forth in Table II were prepared in the manner set forth above.
TABLE II__________________________________________________________________________Element1 2 3 4 5 6 7 8 9 10 11 12__________________________________________________________________________Co 54.85 53 55 60 56 52.83 58.9 52 52 53 55 56Cr 25 23 25 25 26 22 26 25 25 23 25 26Ru 5 10 5 5 5 10 5 5 5 10 5 5Al 2.9 3.9 2.9 3.9 2.9 -- -- 5.9 6 3.9 3 2.9Y 0.1 0.1 0.1 0.1 0.1 -- 0.1 0.1 -- 0.1 1 0.1W 10 10 10 -- 8 10 10 10 10 -- 9 10Mo -- -- -- 5 -- 2 -- -- -- 10 -- --Nb 2 -- 2 -- 2 0.5 -- 2 2 -- 2 --Zr 0.15 -- -- -- -- -- -- -- -- -- -- --Mn -- -- -- 1 -- 0.5 -- -- -- -- -- --B -- -- -- -- -- 0.17 -- -- -- -- -- --Fe -- -- -- -- -- 1 -- -- -- -- -- --Cu -- -- -- -- -- 1 -- -- -- -- -- --__________________________________________________________________________
The physical properties of alloys 1-12 and the percent thermal expansion values (K T ) at 500° C. for alloys 1-4 are given in Table III. The physical properties were measured using an Instron machine. The K T values were measured using a Theta differential dilatometer, where the reference temperature was 30° C., the rate of temperature climb was 3° C./minute and the reference standard was pure platinum.
TABLE III______________________________________ Ultimate TensileAlloy K.sub.T Yield Strength Strength Elongation______________________________________1 .6398 87,000 psi 100,000 psi 8%2 .6480 90,000 psi 108,000 psi 6%3 .6398 97,000 psi 111,000 psi 7%4 .6726 84,000 psi 100,000 psi 6%5 -- 101,000 psi 123,000 psi 6%6 -- 104,000 psi 145,000 psi 14%7 -- 61,000 psi 61,000 psi 0%8 -- too brittle to test9 -- too brittle to test10 -- 34,000 psi 34,000 psi 0%11 -- 62,000 psi 62,000 psi 0%12 -- 73,000 psi 89,000 psi 3%______________________________________
Alloys 1-5, which follow the teachings of the present invention, were each found to have tensile strength and elongation values within the range which is suitable for porcelain-fused-to-metal restorations. Also, each of these alloys was found to have an oxide coating especially suitable for bonding to porcelain.
The remaining alloys (alloys 6-12) illustrate the criticality of the compositions of the alloys of the present invention as well as their improved properties relative to prior art alloys for porcelain-fused-to-metal restorations.
Thus, alloy 6, which was formulated in accordance with U.S. Pat. No. 4,253,869, shows the importance of having aluminum or aluminum/yttrium in the alloy. This alloy was observed to react with the melting crucible and the investment, which is undesirable. In contrast, each of alloys 1-5, which follow the teachings of the invention, were inert with respect to the melting crucible and the investment. Not having aluminum or aluminum/yttrium, as discussed above, alloy 6 was somewhat more ductile, i.e., it had a higher elongation.
The importance of aluminum in preventing reaction of the alloy with the crucible and the investment is further illustrated by alloys 6 and 7. Both of these alloys, which contain no aluminum, were found to react with the crucible and the investment.
The upper limit on the amount of aluminum is illustrated by alloys 3, 8 and 9. Alloy 9 which has 6% aluminum was found to be too brittle to use as a dental alloy for porcelain-fused-to-metal restorations. Alloy 8, which was also too brittle, shows that the addition of yttrium will not cure the brittleness problem at high aluminum. Alloy 3, on the other hand, which has the same composition as alloys 8 and 9 except for its aluminum concentration, was not brittle. This alloy has an aluminum concentration below the upper limit of 4%.
Alloys 4 and 10 illustrate the importance of keeping the concentration of molybdenum below about 6.5%. Alloy 10 with 10% molybdenum was found to be too brittle, while alloy 4 with 5% molybdenum had a 6% elongation which is commercially acceptable.
Alloys 3 and 11 illustrate the effect of high yttrium. Alloy 11 with 1% yttrium was found to be too brittle. Alloy 3 which has essentially the same formulation but with 0.1% yttrium had an acceptable elongation.
Alloy 12 illustrates the importance of keeping the difference between the sum of the tungsten and molybdenum concentrations and the sum of the ruthenium, niobium and zirconium concentrations below about 5%. This difference for alloy 12 is not below 5% and the alloy has an unacceptable elongation of 3%. Alloy 5, on the other hand, has the same composition as alloy 12, but with 2 percent of the tungsten replaced by niobium, and this alloy has an acceptable elongation of 6%. The difference between the sum of the tungsten and molybdenum concentrations and the sum of the ruthenium, niobium and zirconium concentrations for alloy 5 is less than 5%.
Although specific embodiments of the invention have been described and illustrated, it is to be understood that modifications can be made without departing from the invention's spirit and scope. Thus the concentrations of cobalt, chromium, ruthenium, aluminum, yttrium, tungsten, molybdenum, niobium, zirconium and manganese can be varied from the percentages illustrated and alloys having the superior characteristics of the invention will still result. For example, the cobalt concentration can be varied at least between 40 and 60%; the chromium concentration between 20 and 30%; the ruthenium concentration between 5 and 15%; the aluminum concentration between 1 and 4%; the yttrium concentration between 0 and 0.15%; the tungsten concentration between 0 and 15%; the molybdenum concentration between 0 and 6.5%; the niobium concentration between 0 and 3.0%; the zirconium concentration between 0 and 0.25%; and the manganese concentration between 0 and 1.5%. | A cobalt-chromium dental alloy for use in porcelain-fused-to-metal restorations consisting essentially of about:
______________________________________
Element Weight Percent______________________________________Cobalt 40-60Chromium 20-30Ruthenium 5-15Aluminum 1-4Yttrium 0-0.15Tungsten 0-15Molybdenum 0-6.5Niobium 0-3.0Zirconium 0-0.25Manganese 0-1.5______________________________________
wherein the sum of the constituents equal 100% and the sum of the tungsten and molybdenum constituents minus the sum of the ruthenium, niobium and zirconium constituents is less than about 5%. These alloys exhibit outstanding physical and chemical properties, including the formation of a tenacious bond with porcelain without the need for a separate bonding agent, and can be used advantageously as a substitute for alloys having a high proportion of precious metals as well as for nickel-chromium-based alloys in the fabrication of porcelain-veneered fixed bridgework and crowns. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to a system for manufacturing semiconductor under a clean condition, which can be suitably implemented in a semiconductor production plant or the like requiring high degree of freedom from dust.
In semiconductor production plants, it has become essential to provide a dust-free (or ultra-clean) manufacturing condition with increase of integration density of products and increase of fineness of processing. Equipment for providing clean condition of semiconductor production plants thus is important. A system for providing a clean condition which is called an entire down-flow system has heretofore been employed most extensively. In this system, air having passed through a fine dust particle removal filter is caused to flow down through a room so that air in the room is cleaned with this circulation of clean air.
In this system, a large quantity of expensive filters are used to cause circulation of clean air through the entire room. Therefore, high cost is required to provide an increased cleanliness. In addition, the scale of air suction fan is inevitably increased. Furthermore, an upper limit is imposed on the cleanliness, and it is difficult to realize as high cleanliness as class 10 or below. This problem is particularly serious in semiconductor production plants for manufacturing high integration density products such as ultra LSIs or ultra ultra LSIs. For this reason, it has been proposed and practiced to provide a so-called clean tunnel in a transport section to partition the manufacturing section with respect to the other sections. In this case, however, high equipment cost is required. In addition, the borderline of cleanliness is provided only by the clean tunnel. Therefore, expected effect of providing cleanliness can not be obtained.
SUMMARY OF THE INVENTION
An object of the invention is to provide a system for manufacturing semiconductor under clean condition, which is advantageous costwise, permits a highly clean state to be obtained and does not require any large-scale withdrawal fan.
To attain the above object of the invention, there is provided a system for manufacturing semiconductor under clean condition, which comprises a plurality of processing units disposed in a clean room in a low or medium cleanliness state and held in a high cleanliness state, and a transport robot capable of being driven to positions corresponding to the plurality of processing units and-having a self-cleaning function of holding clean a transfer box, in which a workpiece or an object is accommodated, the transport robot being controlled such as to effect transfer of the workpiece or object between its arm and a processing unit when it reaches the position corresponding to the processing unit.
The processing units (and storage stockers, if necessary) are locally held in a highly clean state at all time, and also the transport robot, which transfers a workpiece or object to and from the processing unit (or storage stocker) is locally held in a highly clean state.
The transport robot need not have a self-cleaning function so long as it can hold an object which is accommodated in a carrier in a sealed state in a highly clean state outside the clean room.
The highly clean state may be formed by partitioning the clean room with a partitioning wall, or alternatively, each processing unit may be held in a highly clean state by providing its housing with a filter.
The cleanliness may be varied by varying the mesh of the filter provided on the ceiling of the clean room.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic sectional view showing an embodiment of the invention;
FIG. 2 is a perspective view showing an arrangement of a plurality of structures shown in FIG. 1;
FIG. 3 is a perspective view showing a robot of a transport robot extending into the inner side of a partitioning wall;
FIG. 4 is a sectional view showing a modification of a portion of the embodiment of the system corresponding to a central portion shown in FIG. 3;
FIG. 5 is a perspective view showing a modified transport robot;
FIG. 6 is a side view showing the robot shown in FIG. 5;
FIG. 7 is a back view showing the robot shown in FIG. 5;
FIGS. 8 and 9 are views showing a switch when a hood is open and when the hood is closed, respectively;
FIGS. 10 and 11 show the hood;
FIG. 12 is a schematic view showing an electric circuit of the transport robot; and
FIG. 13 is a perspective view showing wafers as workpieces and a wafer cassette.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a schematic view showing the entire system according to the invention. Reference numeral 1 designates outer walls of a building. The outer walls 1 include a ceiling 2 and a side wall 3. Reference numeral 4 designates inner walls provided on the inner side of and at a suitable distance from the outer walls 1 to form a clean room 12. A room 5 is formed between the inner and outer walls 4 and 1. The inner walls 4 include a ceiling 6, a side wall 7 and a bottom 8. The bottom 8 partitions the interior of the building into first and second story parts 9 and 10. A vertical partition wall 11 is provided between the ceiling 6 and bottom 8 to divide the clean room 12 into two rooms 13A and 13B having different cleanlinesses.
In the building having above structure, a fan 14 is disposed in the first story part of the room 5, and a power source unit 15 and a control panel 16 for controlling the supply of gases and liquid chemicals are provided on the inner side of the side wall 7 in the same story part. A filter 17 is provided in a portion of the side wall 7 in front of the fan 14 to remove dust from air caused to flow from the first story part toward the fan 14. Filters 18 and 19 having different mesh sizes are provided in the ceiling 6 on the opposite sides of the partitioning wall 11. The bottom 8 is provided with holes or openings 20 and 21. Air entering the rooms 13A and 13B from the filters 18 and 19 is returned to the first story part 9 through the holes 20 and 21, thus holding cleanliness of air in each room. While the cleanliness of the room 5 is about class 1,000, the cleanliness of the room 13A is about class 300, and the cleanliness of the room 13B, in which a storage stocker 28 and a processing unit 29 are disposed, is class 1.
The room 13A serves as an operation area with control unit 22 disposed therein. A transport robot 23 can run inside the room 13A. The robot 23 has a body 24 and a head 25 rotatably provided on top of the body 24 and is capable of accommodating an object 31 (not shown) to be transported. The head 25 has an arm 26 for clamping and unclamping the object (i.e., a carrier accommodating semiconductor wafers) 31. The arm 26 can penetrate a hole provided in the partition wall 11 for feeding the object 31 in and out of the storage stocker 28 and processing unit 29 provided in a juxtaposed fashion in the room 13B.
FIG. 2 is an actual arrangement of a plurality of the structures shown in FIG. 1. The entirety shown in this Figure constitutes clean room 12. In this room 12, rooms 13B are formed by partitioning walls and ceiling 6. Guideways 30 are laid on the floor 8. Where the robot 23 is wheeled such as a railway wagon, rails are laid as the guideways 30 on the floor 8. Where the robot 23 is driven by electromagnetic induction, wires or tape-like members, through which AC current can flow, are laid. The robot 23 is guided mechanically or by electromagnetic induction along the guideways 30 to run a predetermined course to a position in front of each room 13B.
FIG. 3 shows the robot 23 held in front of a room 13B for in- or out-feeding the object 31. The robot 23 shown in FIG. 3, has a carrier 31A, in which the, workpiece 31 is sealed in a highly clean state, and is accommodated in the head outside the clean room 12. The head 25 of the robot 23 held in front of the room 13B is turned to bring the arm 26 to a position directed toward the partitioning wall 11, and in this state the arm 26 is inserted into the room 13B through the hole 27 in the partitioning wall 11. In its state extending into the room 13B, the arm 26 transports the carrier 31A to the storage stocker 28 or processing unit 29. Therefore, the arm has a telescopic structure, can be raised and lowered in unison with the head 25 and can be turned in a vertical plane about its portion supported by the head 25.
FIG. 4 shows a modification of the system described above according to the invention. In this instance, the partitioning wall has a double-wall structure, and the transport robot 23 has a self-cleaning function. More specifically, a fan unit 32 and a duct 33 are provided on top of a room 13B, and another partitioning wall 34 is provided on the inner side of partitioning wall 11. A room 35 defined between the two partitioning walls 11 and 34 is communicated with the room 13B through vent holes formed in the partitioning wall 34. A filter 36 is provided in an upper portion of the room 35, and air in the room 13B is circulated through the filter 36 as shown by arrow in the Figure. A filter 37 is provided on the head 25 of the robot 23. This filter 37A withdraws air in the room 13A and provides it to the inside of the head 25 after dust removal. The transport of the object 31 in or out of the storage stocker 28 or processing unit 29 is performed in such a highly clean environment as noted above. In this case, air is supplied to the room 35 by the fan 32, and no air enters the room 13B from the room 13A through the hole 27 in the partitioning wall 11.
In the dust-free transport system having the construction as described above, the transport robot 23 holding the object in a highly clean state is run along the guideways 30 laid in the room 13A. When the robot 23 is brought to a position in front of a storage stocker 28 or a processing unit 29, it is stopped, and the arm 26 is operated. Where the robot 23 has a self-cleaning function, it transports the object 31 to or out of the storage stocker 28 or processing unit 29. Where the robot has no self-cleaning function, it transports a carrier accommodating the object in or out of the storage stocker 28 or processing unit 29. The timing of start and direction of running of the robot 23 and timing of the start of operation of the arm 26 are controlled by a computer. The object 31 is transported through a clean space by a dust-free unit or carrier mounted in the robot 23. Therefore, the cleanliness of the entire plant with the guideways 30 laid therein may be of the order of class 10,000.
Now, a modification of the transport robot will be described.
Referring to FIGS. 5 to 7, reference numeral 41 designates a body of a robot wagon M using a battery as drive source. The robot wagon M is provided at the bottom with wheels, a wheel drive mechanism, guide line sensors and mark sensors. It accommodates a drive controller and a running programmer as well as the battery noted above. Its ceiling is covered by a horizontal cover 45. A robot arm 46 having five degrees of freedom is mounted on a front portion 45A of the horizontal cover 45 of the body 41. A transport box 47 is mounted on a rear portion of the horizontal cover 45.
The transport box 47 has a body 52 and a hood 54. The body 52 has a bottom wall 48, front and rear side walls 49 and 50 with respect to the running direction of the robot wagon M and a back wall 51 formed with a vent hole 51A. The hood 54 has an opening to cover the body 52, and it has a lid 56 having such a sectional profile as to extend along the edge of the opening 13 of the side wall 49 and a cover portion 56 covering the side wall 50 of the body 52. A strip-like edge portion 57 covering the side wall 49 is hinged to the back wall 51. An air cleaning unit 58 is mounted on the outer side of the back wall 51 of the body 52. The air cleaning unit 58 accommodates a fan 59 and a filter 60. An air curtain unit 61 is provided on the outer surface of the side wall 49 with its air blow-out port up. Reference numeral 62 designates a motor-driven fan of the air curtain unit 61. The hood 54, as shown in FIG. 8 (and shown in an open state in FIG. 9), is coupled to the cleaning unit 58 (or body 52) via a hood opening fixing/releasing mechanism (for instance a one-touch stay) 63. The hood opening fixing/releasing mechanism 63 has a cylinder 63A and a rod 63B. The cylinder 63A has one end rotatably coupled to the air cleaning unit 58, and the rod 63B has one end rotatably coupled to the hood 54. Further, a switch (for instance a U-shaped photoelectric switch) 64 is mounted on the upper end of the inner surface of the side wall 50 of the body 52, and it is driven by a dog 65 mounted on the lid 55 of the hood 54. A detection signal provided from the switch 64 is used as a command for energizing a relay Ry shown in FIG. 12. The relay Ry has relay switches RY1 to RY3. A hood for engaging with a robot arm to be opened and closed is mounted on the top of the hood 54. Of the relay Ry, the relay switch RY1 has a function of switching power supplies E H and E L (<E H ), and the relay switch RY2 has a function of switching the power supply E L and zero potential. The relay switch RY3 is provided to inform the robot 46 of the state of the hood 54 (i.e., whether the hood is opened or closed). The power supplies E H and E L are taken out from the battery mounted in the wagon. Designated at D is a diode.
The body 41 accommodates a table 67 to support a wafer cassette C (FIG. 13) set thereon. The table 67 has its end on the side of the back wall 51 supported on the back wall 51 via a hinge mechanism and the opposite end supported by a motor-driven cylinder 68.
Now the operation of the robot will be described. It is assumed that the robot wagon M with a wafer cassette C with wafers W transported onto the table 67 in a processing unit of a certain process is driven toward a processing unit of the next process. At this time, the body 52 of the transport box 47 is covered by the hood 54, and the relay switches RY1 to RY3 of the relay Ry are in their state shown in FIG. 12. Air having been cleaned by the filter 60 in the air cleaning unit 58 is supplied to the inside of the body 52 through the vent portion 51A so that the inside of the body 52 is filled with clean air. During this time, the motor-driven fan 62 of the air curtain unit 61 is held inoperative.
The wafer cassette C is set on the table 67 not in the orientation shown in FIG. 13 but in an orientation obtained as a result of turning down it in the direction of arrow from the illustrated orientation. In this orientation, wafers W are liable to be detached from the wafer cassette C due to vibrations of the robot wagon M being driven. When the wafer cassette C is in a slightly inclined orientation rather than in the horizontal orientation, the wafers W are snugly accommodated in grooves C1 of the wafer cassette C, and their corners are less liable to be broken. Thus, when driving the robot wagon M, the table 67 is tilted by a predetermined angle as shown by dashed lines in FIG. 5 by operating the motor-driven cylinder 68.
When the robot wagon M is stopped at a position corresponding to the processing unit of the next process, the robot arm 46, which is of playback type, commences a preliminarily instructed operation by receiving a command from the running programmer, thus hooking the hood 56 and opening the hood 54 upwards as shown in FIG. 5. The hood 54 is opened upwards by a predetermined angle θ (sufficient to permit operation of the robot arm entering the body 52), and the rod 63B of the hood opening fixing/releasing mechanism 63 is fully extended to secure the rod 63B. At this moment, the switch 64 provides a detection signal.
As a result, the relay Ry is energized, with its switch RY1 switched to the side of the power supply E H and its switch RY2 switched to the side of the power supply E H . The revolving rate of the fan 59 thus is increased to increase the rate of supply of clean air into the body 52. Further, the relay switch RY3 is closed, and a control circuit (not shown) for controlling the arm 46 detects that the hood 54 is opened and provides a reciprocation command to the motor-driven cylinder 68. The rod of the motor-driven cylinder 68 thus is elongated to bring the table 67 back to the horizontal orientation. Thus, clean air is blown out from the inside of the body 52 toward the opening 53, so that entrance of external air into the body 52 through the opening 53 is prevented. At the same time, the motor-driven fan 62 of the air curtain unit 61 is operated to upwardly blow out air along the side wall 49, thus forming an air curtain covering an opening (robot arm insertion/removal opening) 53A formed between the hood 54 in the open state and side wall 49 at the front to shut out external air so that no external air can enter the body 52.
Subsequently, the robot arm 46 is advanced into the body 52 through the opening 53A, takes out the wafer cassette C from the table 67, brings it to the outside through the opening 53 and transports it to the storage stocker 28 or processing unit 29 through the opening 53.
As shown above, in this embodiment clean air is supplied from the air cleaning unit 58 to the inside of the body 52 during the transport of the object, thus preventing dust from entering the inside of the body and attaching itself to the wafers W.
Further, when the hood 54 is opened, the rate of supply of clean air from the air cleaning unit 58 to the inside of the body 52 is increased, and clean air is strongly blown out to the outside through the opening of the body 52 so as to shut the opening 53A between the hood 54 and side wall 49, through which the robot arm 46 is inserted, with an air curtain, thus preventing dust from entering the body 52 during the transport of the object.
In the above embodiment, the storage stocker 28 and processing unit 29 are provided. The storage stocker 28 is necessary when there occurs a trouble in the processing unit 29, and it is not needed so long as the unit 29 is sound. Further, the partitioning wall 11, which serves to partition the storage stocker 28 and processing unit 29 requiring high cleanliness with respect to the chamber 12 requiring low or medium cleanliness, is not essential, and it may be omitted by providing the housing of the storage stocker 28 or processing unit 29 with filter 19 and hole 27.
Further, the guideways 30 are laid on the floor 8 as mechanism for causing running of the transport robot along them, they are not essential. For example, it is conceivable to provide the robot with light-emitting and light-receiving sections for emitting and receiving invisible light such as infrared rays, provide a robot steering mechanism with a structure responsible to the status of reflection of the rays and automatically determine the direction of progress of the robot by detecting the status of reflection of rays by the storage stocker 28 or processing unit 29 or any separately provided guide post. | In semiconductor production plants a highly clean state is required. In a plant building, through which air is forcibly circulated, a clean room in a low or medium cleanliness state is formed using a filter. A plurality of processing units are provided in the clean room and held in a high cleanliness state. A transport robot transfers a workpiece or like object to and from each processing unit. The robot is capable of being driven to positions corresponding to the processing units and holds the workpiece or object in a highly clean state. Thus, there is no need of holding the entire building highly clean, and only a required part of the building may be held in a highly clean state, which is advantageous from the standpoint of cost. | 8 |
The present invention relates to tools for testing and treating earth formations in boreholes and more particularly for making formation pressure measurements, acquiring information concerning formation permeability and productivity, treating a particular formation, and retrieving samples of formation fluids from the treated formation.
DESCRIPTION OF THE PRIOR ART
The commonly assigned and copending application Ser. No. 908,579, filed May 22, 1978 now U.S. Pat. No. 4,210,018, and herein identified as the "RFT" application (issue fee paid), is pertinent and hereby incorporated by reference. Exemplary prior art formation testing tools shown in U.S. Pat. Nos. 3,813,936, 3,780,575, 3,782,191, 3,811,321, 3,858,445, 3,859,850, 3,864,970, 3,924,463, 3,959,851, 3,934,468, and 3,952,558 are abstracted in the "RFT" application.
Also, this invention as described herein is adapted for use in the formation testing tool disclosed in my copending and commonly assigned application Ser. No. 042,431 now U.S. Pat. No. 4,270,385, filed May 25, 1979, which is hereby incorporated by reference.
SUMMARY OF THE INVENTION
The present invention is used with apparatus for achieving formation "shut-in" pressure measurements and for obtaining indications of formation permeability and potential production, and for obtaining formation fluid samples. Such apparatus provides a formation fluid mini-sample chamber having variable volume, and fluid passage means for communicating between the mini-sample chamber and the formation at the seal pad location.
An operator can control the volume of the mini-sample chamber. Signals transmitted to aboveground equipment are a measure of fluid pressure within the mini-sample chamber. Further signals transmitted to the aboveground equipment are a measure of the volume of the mini-sample chamber.
The transmitted signals give the operator an indication of the producing potential of the earth formation being tested. As desired by the operator, the apparatus can be actuated to inject a treating fluid, such as acid, into the formation being tested, give the injected acid some time to react with such formation, then repeat the sampling procedure. In the case of a tight limestone formation, or a formation partially plugged with drilling mud, the treating fluid reaction serves to increase the flow permeability of the formation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram showing the tool of the present invention suspended in a borehole.
FIG. 2 is a schematic longitudinal section view of a portion of the tool of FIG. 1 which shows the fluid treating mechanism of the present invention in the retracted position as when the tool is being lowered into and removed from a well bore.
FIG. 3 is the portion of the tool shown in FIG. 2 with the fluid treating mechanism in position to convey its contained fluid into an adjacent earth formation.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 there is shown a tool 10 of the present invention suspended in a borehole at the location of a formation to be tested, with a seal pad section 12 including backup pads 14, 15 in the set condition. The tool 10 is made up to three primary sections which may be termed the seal pad section 12, the upper tool section 16, and the lower tool section 18.
The cable 20 and winch means by which the tool 10 is suspended and traversed along the borehole, as well as the aboveground equipment, are conventional and consequently need not be described.
Apparatus (not shown) contained in upper section 16 for generating and controlling hydraulic pressure to extend and set seal pad means and backup pad means and to release same, may be referred to as the hydraulic power assembly. The hydraulic power assembly comprises an electrically driven hydraulic piston and cylinder assembly.
Apparatus for conducting various formation tests and for providing and controlling flow valve means may be referred to for convenience as the mini-sample apparatus. The mini-sample apparatus (not shown) is contained within the portion of the upper tool section 16 and comprises an electrically driven mini-sample cylinder piston assembly.
The pad block section 12 carries a sealing pad assembly 22, upper and lower backup pad assemblies 24, 25, and an equalizer valve assembly 26.
The sealing pad assembly 22 comprises a sealing pad 28, sealing pad retainer 30, sealing pad plate 32, upper and lower sealing pad guide rods 34, 36, sealing pad piston 38, sealing pad piston plug 40, and sealing pad cylinder 42. The sealing pad 28 is made of a resilient material such as rubber, which typically may be 60-90 durometer nitrile rubber, and has a generally rectangular shape, with some curvature in transverse section so as to generally conform to the borehole wall curvature.
The sealing pad plate 32 is a metal plate that covers a large portion of the inner surface of the sealing pad.
The upper and lower sealing pad guide rods 34, 35, are secured to the sealing pad plate 32 adjacent its respective upper and lower edges and are reciprocable in respective mating bores. The sealing pad retainer 30 is generally cylindrical having a central bore, a flanged outer end, a cylindrical exterior portion matingly received by a sealing pad central bore, and an exterior threaded portion at its inner end which engages internal threads at the outer end of the sealing pad piston 38.
When the sealing pad retainer 30 is in place, the sealing pad 28 is clamped between the retainer flanged outer end and the sealing pad plate, and the sealing pad plate is clamped between the sealing pad inner surface and the outer end face of the sealing pad piston 38. Thus, the sealing pad and sealing pad plate 32 are securely fixed relative to the sealing pad piston 38.
The sealing pad piston 38 has a first exterior cylindrical surface that extends over about half its length from the center portion outwardly toward the sealing pad 28 and a second cylindrical exterior surface 44 of smaller diameter extending from the center portion inwardly to the inner end.
The sealing pad piston 38 has a cylindrical central bore 46 extending between the internal threads at the outer end portion and internal threads at the inner end portion, which cylindrical central bore 46 merges with and has the same diameter as the cylindrical bore at the inner end of the sealing pad retainer 30.
The sampler pad block 12 has a central transverse bore having a first cylindrical portion matingly and sealingly receiving the first exterior cylindrical surface of the sealing pad piston 38 and merging with a second cylindrical portion of increased diameter for providing a fluid flow passage to and around the sealing pad piston 38.
The sealing pad piston plug 40 has a cylindrical exterior portion that matingly and sealingly engages a first cylindrical interior surface of the sealing pad cylinder and merges with a threaded cylindrical portion of reduced diameter which engages the threads at the inner end portion of the sealing pad piston 38.
The pad guards 24, 25 are sealingly fixed to the pad block exterior surface by bolts and serves to protect the sealing pad 28.
The lower backup pad assembly 15 is similar to the upper backup pad assembly 14.
The equalizer valve assembly 26 comprises a piston 48, a seal ring 50, a retainer plug 52, and a bias spring 54. The sampler pad block 12 is provided a bore 56 for receiving the equalizer valve assembly 26. The piston 48 matingly and sealingly engages adjacent its inner end a portion 58 of the pad block bore 56 with an o-ring seal 60, and adjacent its outer end into a central bore of the seal ring 50. The inner end of the piston 48 is exposed to a hydraulic fluid flow passage, while the outer end is exposed to well bore fluid.
The retainer plug 52 threadedly engages the outer end portion of the pad block bore 56 to hold the seal ring in place within a portion of the pad block bore 56.
The bias spring 52 bears at one end on the seal ring and at the other end on a shoulder on the piston 48, so as to urge the piston inwardly for a purpose to be hereinafter explained.
The lower tool section 18 includes sample chamber means of a conventional design and consequently will not be described herein.
The formation treating apparatus 100 of the present invention is housed within the central bore 46 of the sealing pad piston 38, retained at its outer end by pad retainer 30, and retained at its inner end the pad piston plug 40.
The treating apparatus 100 comprises a fluid container barrel 102 mounted for reciprocation within the central bore 46 and urged toward pad retainer 30 by means of a spring 104 disposed between the inner end of barrel 102 and the bottom of a borehole defined in the piston plug 40.
The outer end of barrel 102 defines an internal valve seat 106 receiving a valve ball 108 urged into sealing relation within seat 106 by a ball spring 110. Spring 110 is mounted in compressed relation against ball 108 by means of a retainer nose 112 threadedly connected into the outer end of the barrel 102. As provided, the ball 108 and seat 106 serve as a check valve permitting fluid flow only from within the barrel 102 to the immediate region at retainer 30.
A fluid ejection piston 114 is slidably mounted within the barrel 102 and a fluid tight o-ring seal 116 is provided intermediate the internal wall of barrel 102 and the external diameter of piston 114. The piston 114 may be retained within the barrel 102 by means of a retainer snap ring 118 as shown.
It is to be noted that the outer end of barrel 102 defines a valve face 122 which engages a valve seat 124 defined in the interior of pad retainer 30. The barrel spring 104 serves to urge the barrel 102 and its face 122 into sealing relation with seat 124. As provided, fluid from a region of formation sealed by pad 28 may flow past valve face 122 into bore 46 and on through passage 37 but may not flow in the reverse direction.
In the operation of this invention, the cavity defined within the barrel 102 and between the valve seat 106 and the face of piston 114 is first filled with a treating fluid 120.
The composition of treating fluid 120 may be varied, depending on the nature of the earth formation to be treated and the nature of the drilling mud particulates which could be plugging the interstices of the earth formations. Acetic acid has been used. Hydrochloric acid, or a mixture comprising hydrochloric acid and acetic acid, may be used. This mixture, sometimes with other additives, may be called a mud clean out agent.
When the tool 10 has reached the test site and the sampler pad section 12 has been extended and set in sealing engagement with the formation and the volume of the mini-sample chamber has been opened up, then the pressure force on the inner face of the piston 38 will be less than that on the outer face, so that the piston shaft will be continually urged into contact with the formation.
As the tool 10 is run into the borehole, all parts are in the positions shown by FIG. 2.
When the tool 10 is stopped at the depth of the earth formation to be tested, the operator energizes the setting motor to force hydraulic fluid through passage 36 to the interior of the sealing pad piston 38 and the interiors of the upper and lower backup pad assemblies 14, 15, thus causing the sealing pad 28 and the backup pads 14, 15 to be extended into contact with wall of the well bore as shown in FIG. 3.
When the hydraulic fluid pressure reaches a designated value, which may be about 1500 p.s.i. above the well bore pressure, then the sealing pad 28 is considered to be set, thus isolating the formation at the sealing pad location.
Next, the operator energizes the mini-sample motor to cause the volume of the mini-sample chamber to begin to increase.
The mini-sample chamber communicates with the formation being tested at the seal pad location via passage means which can be traced from the mini-sample chamber through a passage 37 in the pad block 12 through a further passage 39 in the piston plug 40 to the interior of the sealing pad piston bore 46 which is exposed to the region of earth formation at the sealing pad location.
It should be observed that the operator opens the mini-sample chamber only sufficiently to cause the pressure therein to drop to a point considered to be below the likely formation shut-in pressure, and then de-energizes the mini-sample motor and waits for the mini-sample chamber pressure to build up and stabilize.
If the formation being tested has a low permeability, only a small amount (perhaps only a few c.c.) of formation fluid need be drawn into the mini-sample chamber to achieve formation "shut-in" pressure. If it were necessary to wait for a large test sample chamber to fill before formation "shut-in" pressure is achieved, this could take a long time in the case of low permeability formations.
When the operator determines that the formation being tested manifests a low permeability, yet when other information, as from electrical well logs, indicates that the formation should have a better show, then the treating apparatus of the present invention can be brought into use while the tool 10 remains in the testing position as shown in FIG. 1 so as to treat the identical formation just tested.
To treat the formation, the operator energizes the mini-sampler motor in reverse direction to urge fluids back up through passage 37 and passage 39 into the central piston bore 46 and toward the earth formation sealed off by the sealing pad 28. Fluid pressure is built up in the bore 46, due to the check valve action of valve face 122 against valve seat 124 responsive to urging of spring 104. Such fluid pressure is exerted against the inner side of piston 114 and thereby against the treating fluid 120 contained within the barrel 102. The treating fluid 120 is thereby expelled past the valve ball 108 into the earth formation. The pressure build up in the mini-sample chamber will indicate to the operator that the piston 114 has moved as far as possible in ejecting the fluid 120.
Then operator then waits a few minutes to allow the treating fluid 120 to fully react within the earth formation, then repeats the testing and sampling procedure.
The treating fluid may, or may not, be effective in its reaction within the earth formation to increase the flow permeability of the formation. If the earth formation was plugged near the well bore wall only and is cleaned by the treating fluid, the subsequent test will be better than the initial test. If the formation is naturally tight or plugged back further than can be treated by the available amount of the treating fluid 120, then the subsequent test will likely be not better than the first test.
However, in either event, the present invention has provided a second test of the respective region of earth formation which could not otherwise have been obtained. | Discloses apparatus and method for testing, then treating, then testing the same sealed off region of earth formation within a well bore. Employs a sealing pad arrangement carried by the well tool to seal the test region to permit flow of formation fluid from the region. A fluid sample taking arrangement in the tool is adapted to receive a fluid sample through the sealing pad from the test region and a pressure detector is connected to sense and indicate the build up of pressure from the fluid sample. A treating mechanism in the tool injects a treating fluid into said sealed test region of earth formation. A second fluid sample is taken through the sealing pad while the build up of pressure from the second fluid sample is indicated. | 4 |
BACKGROUND OF THE INVENTION
I. Field of the Invention
Many commercially important coal measures contain substantial proportions of ash. Almost all uses of coal can be accomplished more efficiently by reducing the moisture and ash content of the coal. Especially where the coal is used for generation of heat or electrical power, the moisture content should be reduced to the lowest practical level, and the higher heating value should be as high as possible. Reductions in moisture and ash content produce corresponding increases in the higher heating value of the coal.
My invention relates to a novel chemical coal conditioning process which uses complexing agents such as sodium gluconate in alkaline solution to form soluble compounds with cations such as Al +3 , Fe +3 , Mg +2 , and Ca +2 . I have found that the formation of such compounds reduces the adsorption and/or desorbs clay slimes from the coal surface. In a preferred embodiment of my invention, deashing and dewatering is further enhanced by addition of surfactants such as those disclosed in my co-pending application, Ser. No. 8-047787 filed Apr. 15, 1993, the disclosure of which is incorporated herein by reference.
II. Description of the Prior Art
Some information is available concerning the chemistry of clay/coal interaction. In Burdon, R. G.; Booth, R. W. and Mishra, S. K., "Factors Influencing the Selection of Process for the Benificiation of Fine Coal", Proceedings of the 7th International Coal Preparation Congress, Sydney, N.S.W., Australia, Paper E.1 (1976), for example, a theoretical discussion of the mechanisms of clay adsorption on the organic constituents of coal is presented, and it is hypothesized that Fe +3 and Al +3 cations play a role in promoting such adsorption. Eamer, B. J., "Surface Chemical Treatment of Fine Coal With Slime Problem", M. P. Appl. Sc. Thesis, Western Australian Institute of Technology (1981) and Mishra, S. K. and Eamer, B. T., "Effect of Clay Slimes On Flotation Behavior of Coal", Paper presented at the Fine Particle Society Conference (1985) include similar discussions.
Conventional dewatering and deashing processes may use a rotary drum vacuum filter or comparable device to remove ash and water from slurries of fine coal. A variety of chemical pretreatments have been disclosed to improve the performance of these process steps. U.S. Pat. No. 5,192,338 (Waugh), for example, discloses a treating process using serial treatment with aqueous solutions of citric acid and glycerol at elevated temperature for a period of 30 to 45 minutes to beneficiate coal. Mention is made of the use of "organic complexing agents capable of complexing with metal cations" (col. 3, lines 38-39 and 51-56), but the only reagents disclosed in that category are ethylene diamine tetraacetic acid and its disodium salt; 8-hydroxyquinoline and mercaptoethanol.
U.S. Pat. No. 5,089,142 discloses using sodium hexametaphosphate to control slime formation in centrifugal dewatering processes.
Some investigators, as in U.S. Pat. No. 4,231,868 (Wang, et. al.), have suggested adding sulfosuccinate surfactants to slurries of fine coal in order to improve dewatering efficiency. A similar approach was suggested in U.S. Pat. No. 4,985,162 (Cole). Other researchers also have suggested using sulfur and nitrogen-based compounds, as in U.S. Pat. No. 4,897,201 (Yamomoto, et. al.). The introduction of sulfur-containing surfactants into the coal/water slurry, however, requires application rates substantially higher than those used in my invention. Such surfactants also cause undesirable foam formation downstream of the filtration operation that interferes with subsequent coal processing. Therefore, additional anti-foaming agents may be required. The addition of sulfur to the processed coal is also undesirable from an air pollution standpoint.
Still other investigators have suggested the addition of other reagents to the coal/water slurry. A quaternary amine surfactant was suggested in U.S. Pat. No. 4,892,663 (Keys). U.S. Pat. No. 4,290,897 discloses the addition of organopolysiloxanes and U.S. Pat. No. 4,447,344 (Roe) discloses a variety of ethoxylated alcohols.
None of these references, alone or in combination, suggests that the effectiveness of the coal cleaning processes can be improved by using any complexing agents in basic solution, or by following such treatment with the addition of surfactants such as sodium laureth-13 carboxylate salt in aqueous solution in the form of a foam.
SUMMARY OF THE INVENTION
Improving the effectiveness of specific gravity separation of clay slimes from coal appears to depend upon reducing or preventing the adsorption of the clay slimes onto the organic matrix of the coal itself, and/or desorbing the clay slimes from the coal surface. I have found that the extent to which clay slimes adsorb onto the coal particles can be reduced and/or desorbed by treatment with certain complexing agents; most preferably, with sodium gluconate at low concentration in basic solution. Such pretreatment can be followed advantageously with the addition of a foam made from aqueous solutions of surfactants, preferably sodium laureth 13 carboxylate, to the filter cake which is formed during a subsequent dewatering operation. The combination has been found to provide more effective deashing and dewatering than is obtainable by the use of either an organic complexing agent alone, or by means of a surfactant alone.
Accordingly, one object of my invention is to provide a coal dewatering and deashing process that uses sodium gluconate or related molecules in a basic solution substantially at room temperature to react with various cations, forming water-soluble complexes that prevent the adsorption and/or desorb clay slimes from the organic coal matrix, thereby improving the efficiency of the coal cleaning process.
Another object of my invention is to provide a coal dewatering and deashing process that avoids the use of sulfur-containing surfactants by applying a foamed chemical dewatering agent such as sodium laureth-13 carboxylate salt directly to the permeable cake following pretreatment with a complexing agent in a basic solution, to achieve significant ash and moisture content reductions.
DETAILED DESCRIPTION OF THE INVENTION
In the process of my invention, coal is washed in a conventional coal washing facility, which typically segregates the coal based on particle size. Fine coals are separated from coarse coals and continue through the washing process. Fine coal of -28 mesh typically is further washed using a froth flotation step followed by vacuum filtration of the overhead from the froth filtration operation.
My improvements comprise: (1) the addition to the wash water of a basic (alkaline) aqueous solution of a complexing agent capable of complexing with the cations that are naturally present; and (2) the application to the surface of a permeable cake of a dewatering foam made from aqueous solutions of carboxylic acid or carboxylate salts according to the process of my copending application Ser. No. 8-047787 filed Apr. 15, 1993, the disclosure of which is incorporated herein by reference. Complexing agent addition alone improves the results of conventional deashing and dewatering operations; still further improvement is obtained by complexing agent addition followed by the use of a dewatering foam.
More specifically, I have found that the following complexing agents can be used to improve the efficiency of dewatering, ash removal and increase the yield of clean coal: gluconic acid, glucaric acid, gulonic acid, glucoheptonic acid and glucuronic acid as well as their sodium and potassium salt forms. It should be understood that other additional reagents could be added to promote the deashing of the coal. Such other promoter reagents include: ethylene diamine tetraacetic acid (EDTA), pyrophosphate, hexameta phosphate, hydroxy ethylidene diphosphonic acid, amino methylene tri phosphonic acid, phosphonobutane tricarboxylic acid, hexa methylene diamine tetra phosphonic acid, polyacrylic acids, polymethacrylate, acrylate-acrylamide copolymer and maleic anhydride copolymer.
The concentration of complexing agent following its addition to the wash water should be between about 50 and 5000 lbs of active complexing agent per one million lbs of wash water. The most preferred complexing agent concentration corresponds to a loading of approximately 500 lbs of active complexing agent per one million lbs of wash water. The amount of complexing agent required depends upon the specific complexing agent used the coal chemistry, the hardness of the wash water, and the solution pH. However, the specific application can be optimized by using simple laboratory testing procedures.
At the time the complexing agent is added, the pH of the wash water should be adjusted to between about 7.0 and 12.0, and most preferably about 9.0 by addition of suitable bases (e.g., NaOH or KOH).
The complexing reactions will be sufficiently complete within about 5 minutes from the time the coal contacts the wash water. Reaction times can be further shortened by altering concentration and/or pH.
In the preferred embodiment of my invention, the next processing step is continued washing and separation of coal particles based on particle size. Finer particles (minus 1/4 inch) are separated from coarse particles for further processing and/or dewatering. Typically, coal particles ranging in size from minus 1/4 inch to plus 28 mesh are next dewatered using modified screen bowl centrifuges. The minus 28 mesh coal is further washed using a froth flotation cell. The froth removed from the top of the froth flotation cell is then dewatered via rotary drum vacuum filtration. The effectiveness of dewatering using centrifugal dryers and rotary vacuum systems can be enhanced by using the dewatering foam technique described in my copending application Ser. No. 8-047787 filed Apr. 15, 1993. Any of the dewatering foams disclosed in that application can be used in the process of this invention following the complexing and froth flotation steps.
Laboratory tests were performed to determine quantitatively the performance of certain specific embodiments of my invention. The examples are solely illustrative and do not restrict the scope of my invention.
EXAMPLE 1
About 2750 ml. of aqueous solution containing approximately 1000 ppm of 50 wt % gluconic acid was prepared. Its pH was raised to about 9.0 by adding NaOH. Approximately 250 grams of -28 mesh bituminous Elkhorn no. 2 coal was added. The slurry was mixed and aerated for 5 minutes. The duration of the mixing was selected to duplicate the residence time associated with actual froth flotation cell used at coal processing facilities. After 5 minutes, about 2 ml. of kerosene was added to the slurry and the froth was removed using a collection header attached to a vacuum system. The collected froth was dewatered using a standard vacuum filtration system.
A blank was run under the foregoing conditions without gluconic acid. The results of these test were:
______________________________________ % ash dry basis______________________________________Blank 9.36Treated 6.34______________________________________
Thus, the washed coal that was exposed to gluconic acid treatment had about 56% less ash.
EXAMPLE 2
Two blanks and a treated sample were prepared using the procedure of Example 1. Residue from the bottom was collected and analyzed for ash content. The results were:
______________________________________ % ash dry basis______________________________________Blank 1 24.86Treated 35.54Blank 2 25.71______________________________________
The increased ash content of the residue further demonstrates that more of the organic matrix of the coal was liberated from the ash, thereby decreasing the ash content and increasing the yield of the washed coal.
EXAMPLE 3
A blank and a treated sample were prepared as described in Example 1. The collected coal removed as froth was then dewatered using a Buchner funnel system controlled at a 15" Hg vacuum for 1 minute. Approximately 0.45 lbs of foamed dewatering agent (specifically, sodium laureth 13 carboxylate) per ton of dry coal was applied as a foam at a 10:1 expansion ratio to both the blank and the gluconic acid-treated sample using the process described in my copending application Ser. No. 8-047787. The results were:
______________________________________ % moisture______________________________________Blank 35.3Blank with dewatering foam 30.1Treated sample 32.5Treated sample with dewatering foam 18.6______________________________________
Thus, the addition of pretreatment with gluconic acid complexing agent to the process of my copending application Serial No. 8-047787 produces a further 43% improvement in dewatering efficiency.
It will be apparent to those of ordinary skill in the art that changes and modifications could be made while remaining within the scope of my invention. For example, other foamed dewatering agents could be used, as disclosed in my copending application Ser. No. 9-047787 It is my intention, therefore, to cover all such equivalent processes, and to limit my invention only as specifically set forth in the following claims. | A process for improving the efficiency of coal dewatering and deashing uses complexing agents such as sodium gluconate in alkaline solution to form soluble compounds with cations such as Al +3 , Fe +3 , Mg +2 , and Ca +2 . The formation of such compounds reduces the adsorption and/or desorbs clay slimes from the coal surface. | 1 |
BACKGROUND OF THE INVENTION
The background of the invention will be set forth in two parts.
1. Field of the Invention
The present invention pertains generally to hand tools and more particularly to a new and useful hand tool especially designed for removing a movable member from a confined space adjacent a fixed member.
2. Description of the Prior Art
Removal of the upper arcuate main bearing shells from an engine block have been a problem.
It sometimes takes two men several minutes to remove these bearing shells. One man works the crankshaft while the other man takes a flexible thin tool, like a long feeler gauge, and taps the bearing shell around the bearing surface a little at a time. This flexible thin tool must be used in extremely cramped quarters, further adding to the problem.
U.S. Pat. No. 3,886,644 discloses an upper main bearing removal tool including a reciprocable member mountable on one of the stud bolts between the nut and the engine block. The reciprocable member has a pawl pivotably mounted thereon. The pawl extends toward the main bearing seat when the reciprocable member is mounted on the stud bolts and is biased away from the stud bolt. The tool also includes an arcuate member substantially similar to the main bearing shell. This arcuate member has ratchet teeth cut in its outer surface and is effective when placed against the crankshaft bearing surface with one end abutting the end of the main bearing shell nearest the pawl to engage the pawl with its ratchet teeth and push the main bearing shell out of the main bearing seat as the nut on the stud bolt is screwed alternately down and back.
One difficulty with this tool resides in the fact that it is time consuming to set the tool up initially. Another difficulty resides in the fact that it is also time consuming to alternately screw the nut on the stud bolt down and back.
SUMMARY OF THE INVENTION
In view of the foregoing factors and conditions characteristic of prior art hand tools for removing a movable member from a confined space adjacent a fixed member, it is a primary object of the present invention to provide a new and useful hand tool of the type described which is especially designed for removing movable members, such as upper main bearings, from a confined space, such as a bearing seat in an engine block, adjacent a fixed member efficiently and expeditiously.
According to a presently-preferred embodiment of the invention, a hand tool is provided for removing a movable member from a confined space adjacent a fixed member. The tool is shown herein for purposes of illustration, but not of limitation as comprising a main bearing removal device for use with an engine having a block with at least one arcuate bearing seat, a crankshaft having a journal surface adjacent the bearing seat, an arcuate bearing shell in the arcuate bearing seat between the bearing seat and the crankshaft journal surface and at least one shoulder on the block adjacent the bearing seat for receiving one end of a bearing cap.
The device may comprise a first lever for engaging the shoulder, a second lever for engaging the arcuate bearing shell and a link pivotably connecting the first and second levers together near their working ends for pivotal and axial movements with respect to each other, whereby the levers may be squeezed together causing the working end of the second lever to dig into the arcuate bearing shell whereupon the second lever may be pulled axially to move the arcuate bearing shell one increment. The second lever may then be moved axially toward the arcuate bearing seat for a fresh bite.
The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawing in which like reference numbers refer to like elements in the several views.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a partial perspective view of an engine block looking in from the bottom after the pan, piston rods and one main bearing cap have been removed;
FIG. 2 is a perspective view of a hand tool constituting a presently-preferred embodiment of the invention;
FIG. 3 is an enlarged cross-sectional view taken along line 3--3 of FIG. 2;
FIG. 4 is a longitudinal, partial cross-sectional view of the tool of FIG. 2;
FIG. 5 shows a portion of the engine block of FIG. 1 greatly enlarged and in cross-section with the tool of FIG. 2 in position preparatory to making a working stroke; and
FIG. 6 is a view similar to FIG. 5, but showing the tool of FIG. 2 after it has made a working stroke.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring again to the drawing, and more particularly to FIGS. 2-4, a hand tool constituting a presently-preferred embodiment of the invention, generally designated 10, includes a first lever 12 having a work-engaging end 14, a second end 16, which defines a hand grip, and an intermediate portion 18.
Work-engaging end 14 is undercut to provide a flat land 20 and a slight shoulder 22. The intermediate portion 18 is provided with a transverse, elongated bore 24 providing working room for one end 26 of a link 28 pivotably secured to intermediate portion 18 by a bolt 30 and a nut 32. Link 28 includes a second end 34 pivotably mounted in a second elongated, transverse bore 36 provided in the intermediate portion 38 of a second lever 40 having a work-engaging end 42 and a second end 44, which defines a second grip portion. Lever 40 may be bent, as shown at 45, so that grip portion 44 diverges outwardly from grip portion 16; this provides working room between levers 12, 40 for the hands of a user of tool 10. End 34 of link 28 is connected to intermediate portion 38 by a bolt 46 and a nut 48. Work-engaging end 42 of lever 40 carries a blade 50 having a first end 52, which may be sharpened to provide a cutting edge, and a second end 54 (FIGS. 3 and 4) which may be adjustably mounted in a channel 56, which is provided in work-engaging end 42. Blade 50 may be retained in position in channel 56 by a set screw 58 (FIG. 2) and may be adjusted so that tool 10 may be used on engines of different sizes.
Referring now to FIGS. 1, 5 and 6, although tool 10 may be used for removing any movable member from a confined space adjacent a fixed member, it may be advantageously used as a main bearing removal device for use with an engine 60 having a block 62 including an open bottom 64 and side walls 66, 68.
A crankshaft 70 is rotatably mounted in block 62 and includes suitable journal surfaces, like the one shown at 72, adjacent suitable arcuate bearing seats, like the one shown at 74 in FIGS. 5 and 6. An arcuate bearing shell or main bearing insert 76 may be mounted in bearing seat 74 between bearing seat 74 and crankshaft journal surface 72.
The crankshaft 70 is secured in position in block 62 by suitable bearing caps, like the two shown at 78, 80 in FIG. 1. Caps 78, 80 provide bearing seats for the lower half of the main bearing inserts (not shown) and may be secured to block 62 by cap screws 82 which threadedly engage tapped apertures 84 provided in block 62 adjacent suitable shoulders 86 against which the ends 88, 90 of bearing caps 78, 80 seat.
Operation of tool 10 will now be described in connection with FIGS. 5 and 6. A screwdriver or the like (not shown) may be applied to one end 92 of insert 76 (FIG. 5) and tapped lightly so that insert 76 will be moved slightly to expose its other end 94. The land 20 on work-engaging end 14 of lever 12 may then be seated against shoulder 86 and work-engaging end 42 of lever 40 may be positioned adjacent exposed end 94 of insert 76. Lever 40 may then be swung toward lever 12 in the direction of arrow 96 causing cutting edge 52 of blade 50 to bite into exposed end 94 of insert 76. While lever 12 is held firmly in engagement with shoulder 86, and while pressure is continued on lever 40 in the direction of arrow 96, lever 40 may be pulled axially downwardly, as indicated by arrow 98 in FIG. 6, causing end 94 of insert 76 to move a slight increment, as indicated by arrow 100, along a path defined by arrow 102.
Lever 40 may then be released and moved upwardly until blade 50 is again in its FIG. 5 position whereupon lever 12 is held firmly while lever 40 is moved in the direction of arrow 96 to bring cutting edge 52 into engagement with a newly exposed portion of end 94 of insert 76. Lever 40 may then be moved axially downwardly to expose another portion of insert 76. These operations may be rapidly repeated until insert 76 has been moved from the upper portion 104 of journal surface 72 to its lower portion 106.
A number of different materials from which tool 10 may be made will manifest themselves to those skilled in the art. For example, levers 12, 40 and link 28 may be made from mild steel. Blade 50, on the other hand, may advantageously be made from a carbide material. Additionally, each grip portion of levers 12, 40 may be provided with a shrunk-fit, polymeric sleeve (not shown), if desired.
While the particular hand tool herein shown and described in detail is fully capable of attaining the objects and providing the advantages hereinbefore stated, it is to be understood that it is merely illustrative of the presently-preferred embodiment of the invention and that no limitations are intended to the details of construction or design herein shown other than as defined in the appended claims, which form a part of this disclosure.
Whenever the term "means" is employed in these claims, this term is to be interpreted as defining the corresponding structure illustrated and described in this specification or the equivalent of the same. | A first lever has an end which engages the fixed member, a second lever has an end which will dig into the movable member and a link is pivotally connected to each lever adjacent its working end so that both levers may be squeezed together causing the working end of the second lever to dig into the movable member. The second lever may then be moved axially to pull the movable member. | 8 |
BACKGROUND OF THE INVENTION
Related Application
The U.S. application for patent Ser. No. 745,052 entitled "Mudline Casing Hanger Tieback Adaptor With Adjustable Load Ring" filed even date herewith by Jose M. Alandy.
Field of Invention
This invention relates, in general, to subsea well systems and is directed to a method and apparatus for converting a mudline suspension system to a subsea wellhead system. More specifically, this invention is directed to a method and apparatus for placing a wellhead in a mudline suspension system and connecting this wellhead in such a manner that all loads imposed later on the wellhead in subsequent operations are transferred to the outer conductor pipe of the mudline system.
A mudline suspension system is run with a jack-up drilling vessel which is ocean bottom supported, i.e., is a stationary drilling rig. Since the rig is not moving, the outer conductor pipe strings and inner casing strings are suspended at or near the mudline and run from the mudline up to the drilling platform. Thus, the wellhead is effectively above the platform where land-type blowout preventers are installed for pressure control during drilling operations.
A subsea wellhead system is run from a floating drilling vessel which is subject to wind, waves, and heave. Thus, motion compensators, one or more ball or flexible joints, and marine riser strings are used to account for all movements of the floating vessel.
Although the two drilling operations are distinct, it is sometimes desirable to convert the mudline suspension system to a subsea wellhead system. Thus, an exploratory well drilled, using the less expensive mudline suspension system, may be converted to a production well with completion equipment, i.e., a tree connected subsea. The exploratory well may also be connected by flowlines as part of a subsea multi-well system.
In order to make this conversion, however, it is important that the subsea wellhead that is being used for the conversion be properly tied down to the mudline suspension system. This subsea wellhead is tied down to the outermost conductor pipe, as stated before, must effectively transfer loads from the wellhead to the outermost conductor pipe, and must provide adjustability in both the longitudinal and the radial directions.
It is therefore an object of this invention to provide a method and apparatus used as one of the preliminary steps in converting a mudline suspension system to a subsea wellhead system.
A more particular object of this invention is to provide a subsea wellhead and a lockdown connector which will connect the wellhead to the outermost conductor pipe while providing adjustability in both the longitudinal and radial directions in such a conversion.
More specifically, it is a further object of this invention to provide a lockdown connector which will effectively transfer load from the selected subsea wellhead to the outermost conductor pipe.
SUMMARY OF THE INVENTION
The method and apparatus which accomplishes the foregoing objects comprises a lockdown connector which connects a subsea wellhead to the outer conductor pipe of the mudline suspension system.
This lockdown connector is bell-shaped with internal threads which mate with external threads on the subsea wellhead and radial locking dogs to mate with a peripheral groove in the pin connector formed on the outer conductor pipe. This bell-shaped connector preloads in two areas to provide a more rigid connection between the subsea wellhead and the outer conductor pipe. It first preloads between the wellhead threads and the nose of the pin connector in the outer conductor pipe, and secondly preloads between the pin connector nose and the dog groove of the pin connector. Such a rigid preloaded connection is required to tolerate any eccentricity between the mudline tieback tool, the wellhead, and the outer conductor pipe, allow an adjustability in the axial direction to compensate for any stack buildup between the mudline casing hangers and the conductor pipe connector, and provide a rigid preloaded connection to resist any tensile, bending, and/or shear forces while reacting such forces on the wellhead directly to this outer conductor pipe.
Other advantages of this method and apparatus will be apparent to those skilled in the art after having studied the accompanying drawings and the following Detailed Description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view illustrating the mudline system, the lockdown connector of this invention, and a hydraulically actuated suitable connector for connecting the mudline system to the platform for later well operations,
FIG. 2 is an enlarged cross-sectional view taken along line 2--2 of FIG. 1,
FIG. 3, taken along line 3--3 of FIG. 1 incorporates the lower part of FIG. 2 and illustrates the lockdown connector connected between the wellhead and the outermost conductor pipe,
FIG. 4, taken along line 4--4 of FIG. 1 is an extension of FIG. 3 to illustrate details of the wellhead system,
FIG. 5 is an enlargement of the area, defined by the arrow 5, in FIG. 3 to illustrate the lockdown connector in more detail, and
FIG. 6 is an enlarged cross-sectional view taken along line 6--6 of FIG. 5 to illustrate the details of the locking dog assembly of the hydraulically actuated connector.
DETAILED DESCRIPTION
As shown in FIG. 1, an outer conductor pipe 10 of the mudline suspension system, indicated in its entirety as 12, located at the mudline 14, is shown with a hydraulically actuated connector 16. The latter connects the mudline system to the platform through tubing 18 after the subsea wellhead has been connected to the mudline system as part of the conversion of the mudline system to a wellhead system.
This outer conductor pipe 10 has been cemented in a previously drilled hole in the ocean floor, is conventionally a pipe 30" in diameter, and is part of the first conductor pipe run into the well bore and cemented in place. This figure also shows a lockdown connector 20 used in practicing this invention. How this latter piece of equipment is used will be described later.
The shown outer conductor pipe 10 was originally made up of several lengths of such pipe, connected together, and extending from the mudline to the platform of the stationary drilling rig.
Each conductor pipe 10 making up the string was preferably connected by a pin and box connection, such as shown in the U.S. Pat. No. 3,381,983, to Hanes, entitled "Connectable and Disconnectable Tool Joints" or the U.S. Pat. No. 3,606,393, to Huntsinger, et al., entitled "Pipe Connectors". The pin portion 22 of the connector sometimes called simply "pin 22" used in practicing this invention is shown in FIG. 3.
After the 30" outer conductor 10 is cemented in place, the standard practice is to drill smaller and deeper holes and then run additional and smaller casing strings using suitable running tools. These casing strings are conventionally suspended at the mudline and cemented in place utilizing conventional techniques. Typically, the next inner casing, after positioning the 30" outer conductor 10, is a 20" casing 24, then a third 133/8" casing 26. Thereafter, a 95/8" casing 30 is suspended in the conventional manner and cemented in place. At each step after cementing the outer conductor pipe 10 in place, the annular space between the casing strings are sealed and tested.
FIGS. 3 and 4 illustrate the second 20" casing 24 having landed and supported on an inner profile 32 on the outer conductor 10 by a landing ring 34, as is conventional. The 135/8" casing 26 is also shown supported by the casing 24 on a profile 36 and landing ring 40 on a casing hanger 42, as is conventional. The next 95/8" casing 30 is suspended on a casing hanger 44 (only partially shown) and collet 46.
Thus, all necessary casing have been run, landed, and cemented by suitable running tools to make a complete mudline suspension system. The system thus far described is conventional and well known.
When it is decided to make the conversion to the subsea well system, the corrosion cap, tools, and all inner casings above the mudline are removed leaving only that inner casings which had been cemented in place at the mudline. The outer conductor string made up of the segments of conductor pipe 10, remain intact.
The next step is to run the mudline wellhead adaptor 50, sometimes called simply "wellhead 50" and a tieback tool 52 on a running tool, connected to drill pipe, through the string of conductor pipes 10 to the 133/8" casing hanger 42 and to thread the tool onto the casing hanger 42 and to test the seal therebetween. The wellhead adaptor has external threads 54 on its lower end which engage internal threads 56 on the top of the tieback tool, when the two are connected together to be lowered by the running tool. The wellhead adaptor has J-slots 60 shown in FIGS. 2, 3 and 5 for attachment to the running tool.
The tieback tool 52 is a sleeve which will connect wellhead adaptor 50 to the 133/8" casing hanger 42 and, in addition to threads 56, is provided with external threads 62 midway thereof for mating with internal threads 64 below the top 66 or mouth of the 133/8" casing hanger 42. The tieback tool is provided with a metal-to-metal seal assembly 68 which engages a tapered surface 70 on the inner periphery of the 133/8" casing hanger 42, and when the tieback tool 52 has landed and is threaded onto the casing, the tieback tool 52 will be shouldered as at 72 on the top of the casing hanger 42 and the metal-to-metal seal will be made up. In this position, the integrity of the seal assembly 68 is tested.
This wellhead adaptor 50 is conventional in shape in its main upper body portion 74, that is, it is provided with a profile 76 on the outer periphery thereof, for connection to the connector 16 as shown in FIG. 2. The profile is a series of grooves formed a short distance below the top 80 or nose of the wellhead. The wellhead is further provided with internal threads 82 for tieback and running tools on its inner bore. For this system, however, the main body portion 74 is provided a downward thinner extension 84 formed by reducing the outer diameter of the wellhead. This latter extension 84 has the external threads 54 by which it is connected to internal threads 56 on the top of the tieback tool, as shown in FIG. 3.
The next step in the conversion is to disconnect all of the conductor pipes 10 of the string above the mudline, leaving only the pin connection 22 as mentioned above.
The split lock ring in groove 94 is removed from the pin 22 to allow the lockdown connector 20 to be used. This split lock ring, though not shown in the drawings, corresponds to the lock ring 22 in the Hanes Patent and the lock ring 28 in the Huntsinger, et al. Patent, supra.
Removal of the split lock ring from groove 94 prepares the pin 22 to receive the lockdown connector 20, and the next step is to connect the lockdown connector 20 to a suitable running tool 96. Since the running tool 96 is the convention type with J-slots 100 to receive the lugs 102 on the outer periphery of the tubular portion 104 of the lockdown connector, it is shown only in phantom.
More specifically, as can be seen in FIGS. 3 and 5, the lockdown connector 20 is a bell-shaped body having the upwardly extending tubular portion 104, which is internally threaded at 106 to engage external threads 110 on the main body portion 74 of the wellhead. The threads are modified square threads. Between the tubular portion 104 and a downwardly extending wall or skirt 112 is a radially outwardly extending wall 114 which, with the tubular portion 104 and downwardly extending wall 112, form the bell shape. As shown in FIG. 5, the downwardly extending wall 112 and the thinner extension 84 of the wellhead span the pin connection 22 and the inner bore of the 133/8" casing hanger 42. The lugs 102 are, of course, located on the outer periphery of the tubular portion 104, as shown.
The lockdown connector is also provided with a plurality of bolt/dog assemblies 116 which will effectively connect the wellhead 50 to the outer conductor pipe 10 when the lockdown connector 20 is lowered onto the wellhead housing and the pin 22, of conductor pipe 10 as will now be explained.
As mentioned above, it is important that the lockdown connector not only connect to the selected subsea wellhead 50 and to the conductor pipe 10, but provide adjustability in both longitudinal and radial directions and effectively transfer load from the wellhead 50 to the conductor pipe 10.
To do this, the lockdown connector is first rotated by the running tool and threaded onto the threads 110 on the wellhead so that the inner surface of the radially extending wall 114 will engage the top 120 or nose of the pin 22. This provides a preload between the top of conductor pipe 10 and the threads 110 on the wellhead. Thereafter, the bolt/dog assemblies 112 are actuated to urge dogs 122 into the groove 94 to tightly engage the groove 94. This preloads the pin 22 and the lockdown connector 20 in the groove 94.
FIG. 6 illustrates in detail one of the bolt/dog assemblies 116 which comprises essentially a head or boss 124 bolted onto the downwardly extending wall 104 which positions the dog 122 in an aperture 126 in wall 112 and into the groove 94. The actuator for urging the dog 122 comprises a threaded actuator screw 126 threaded in the boss 124, coupled to the dog 122, and actuated by a wrench on hexagonal head 134. To prevent backoff of the dog 122, a suitable spring actuated lock plate 136 engages the hexagonal head. This assembly is similar to the actuator devices 40 described and shown in the Huntsinger, et al. Patent, supra, to which reference is made if further information about this type of assembly is required.
Finally, to connect the now partially converted mudline suspension system to a platform, the hydraulically actuated connector 16 is lowered via tubing 18 and connected to the wellhead 50. This connector includes hydraulically actuated dogs 140 which engage the profile of 76 on the upper end of the wellhead 50 and essentially locks the wellhead to the tubing 18. This connector 16 is disclosed and claimed in the U.S. Pat. No. 3,321,217 to Ahlstone, to which reference is made if further details are thought necessary. This is a well-known connector used extensively in subsea systems.
Later, a casing hanger 144 of the conventional type may be landed in the conventional way within the wellhead 50.
From the foregoing, it can be seen that there is disclosed a method and apparatus by which a mudline suspension system can be converted into a subsea well system through the use of a connector and a subsea wellhead and a lockdown connector. This lockdown connector performs the necessary function to the conversion by preloading in two areas to provide a more rigid connection between the modified wellhead and the outer conductor pipe to essentially transfer all loads imposed on the wellhead to the outer conductor pipe for later wellhead operations. | Disclosed is a method and apparatus comprising a lockdown connector 20 which connects a subsea wellhead 74 to an outer conductor pipe 10 of the mudline suspension system 12 to convert a mudline suspension system to a subsea well system while providing adjustability in both the longitudinal and radial directions and providing a means by which loads imposed on the wellhead are transferred to the outermost conductor pipe. | 4 |
BACKGROUND OF THE INVENTION
This invention relates generally to anchoring means, and more particularly pertains to a multipurpose anchor for providing permanent fixation within the ground.
Numerous styles of screw anchors, or other types of anchoring means, have long been available in the art, and most of these anchors are designed for being either manually, but preferably powered by a tool for turning into secure confinement within the ground. Many of these anchors have their own particular style of helical blade for accomplishing their own sought for results, and perhaps each of these prior art anchors do attain that result for which they were originally intended to perform.
The U.S. patent to Jahnke, U.S. Pat. No. 3,793,786, discloses a type of screw anchor where its lower end is formed having a screw type of shank, with a helical flight of blade arranged thereabove to supplement the digging action of the said shank. It is to be noted that the leading cutting edge of the helical flight for the blade of this patent is arranged significantly at a perpendicular angle radially away from its shank.
The U.S. patents to Roza, U.S. Pat. Nos. 3,645,055, and 3,662,436, in addition to the U.S. patents to Petres, U.S. Pat. No. 3,828,562, and the additional Jahnke U.S. Pat. Nos. 3,832,860 and 3,832,861, disclose methods and apparatus for installing anchors, but the particular style of anchors shown are what are identified as helical screw type blades that are connectible with and have leading edges that blend into their hub portion and expand in width therefrom, then exhibiting an extending elongated portion formed at the upper end of the helix. This particular style of helical formed cutting blade, and its connection with the shank portion of the screw anchor, is more clearly shown in detail in the U.S. patent to Petersen, U.S. Pat. No. 3,016,117. There apparently are certain advantages to be attained from a screw anchor having a cutting edge that is arculate in shape, and curves around its shank portion from its leading edge.
Similar type anchors are shown in the U.S. patents to Smith, U.S. Pat. No. 1,193,725, Bash, U.S. Pat. No. 1,883,477, Dray, U.S. Pat. No. 1,388,031, Maloney, U.S. Pat. No. 1,283,246, and Widmer, U.S. Pat. No. 816,631.
While all of the foregoing prior art anchors are probably effective for their intended purpose, the current invention is designed to provide a modification to what is disclosed in the prior art, and that is to form a linear cutting edge at a lagging angle with respect to the radius or perpendicular from its mounting shank portion, and thereby provide a length of cutting edge that is more effective in providing for the bite or slice of the anchor into the ground, and at the same time, because of its designed lag angle, effectively urges any rock or other debris encountered in the ground further laterally for eventual movement outside of the perimeter of its helical blade.
It is, therefore, a principal object of this invention to provide an earth anchor that effectively sheds any rock or other debris encountered by its leading edge during its turning into the ground, without detracting from the effectiveness of its linear cutting edge to dig into the ground during progressive turns of its shank.
Another object of this invention to provide an earth anchor that disposes its cutting edge along a lagging angle from the shank portions radius so as to enhance the slicing effect of its helical blade while digging into the soil during a turning of said anchor.
Another object of this invention is to provide an angularly oriented linear cutting edge for an earth anchor that effectively sheds rock to the side without any deleterious damage to its cutting edge, the structural configuration of its helical blade, or supporting shank portion.
Yet a further object of this invention is to provide an earth anchor that may incorporate a series of spacedly arranged integral helical blades along the length of the shank portion of said anchor, and significantly enhance the holding power of the anchor to the ground.
Yet another object of this invention is to provide connecting means for attaching a series of shank portions of an earth anchor together so as to provide an anchor of infinite length, or to that length called for in the design and as desired for the particular installation.
Still another object of this invention is to furnish an earth anchor having an end cap, and which cap may incorporate a series of secured reinforcing rods that may form the basis, with the earth anchor for supporting a concrete pile or foundation.
Still another object of this invention is to provide an earth anchor that may be easily assembled, and quickly embedded into the ground through the use of conventional power equipment.
These and other objects will become more apparent to those skilled in the art upon reviewing the summary of this invention, and upon undertaking a study of its preferred embodiment in view of the drawing.
SUMMARY OF THE INVENTION
This invention contemplates the formation of a particularly styled earth anchor, of the type that is designed for forceful embedment within the ground. And, an anchor of this nature has multiple uses, can be applied as a means for attachment of guy wire for support of a telephone or other type of pole as balanced with respect to the ground, to be used as an anchor for deep embedment within the ground, or to be used in the nature of a helical pile for supporting concrete piles or foundation, or for other similar purposes. In addition, and to facilitate the efficient usage of this earth anchor, particularly when it is being turned or driven into the earth, the helical blade of the anchor incorporates a linear slicer or cutting edge, and which edge is arranged at a lag angle from the radius of the shank to which the blade is integrally attached. In this manner the blade effectively slices into the ground as the anchor is being forcefully turned through the use of associated power equipment, and due to the cutting edge of the blade being arranged upon an incline with respect to the shank with which it turns, it conveniently slices into the ground along its sharpened leading edge. Furthermore, because of the lag angle between the blade cutting edge and the radius from the shank portion to which it mounts, any debris, rock, or other material that retards the effective digging of the anchor into the ground, during its installation, is conveniently shoved to the side as a result of the rearward incline of the linear blade edge with respect to its turning shank portion.
In order to provide for the effective use of this anchor in those positions where significant forces are required to resist the pull of tension as exerted upon the anchor after its installation, a series of two or more of the anchors may be coupled together, so as to provide an anchor of infinite length, or at least to that sizable length previously researched as being required to resist the forces to be applied upon the anchor after its embedment. In addition, and as previously briefly alluded to, the anchor of this invention may be used as undersupport for pilings, foundations, or related type of construction structures. To achieve this, an end cap is provided for the upper end of an emplaced anchor, and the cap has welded or otherwise secured thereto a series of laterally arranged reinforcing bars, so that when concrete may be poured into the foundation cavity dug into the earth, with the anchor having been embedded into its bottom, and having its cap and reinforcing bars extending slightly upwardly therefrom, such concrete as poured therein envelopes such reinforcement with the anchor providing further support to the building foundation being formed.
Various tests have been conducted to determine the holding power of the earth anchor of this design, and the following chart discloses the relationship between the foot pounds of torque necessary for driving the identified anchors into the ground, and the amount of holding strength in compression that can be resisted by the anchor after its installation. The D figure refers to the design number of the anchor being tested, and also provides its diameter range.
______________________________________TORQUE VS BEARING STRENGTH FOR EARTHANCHORS HOLDING STRENGTH IN COMPRESSION/LBS. D-126637 D-126638FT/LB D-126632 D-126636 10"-11.3"- 10"-11.3"-TORQUE 8"-10" 8"-10"-11.3" 13.5" 13.5"-15"______________________________________3000 25,500 26,700 26,900 30,4004000 28,100 34,700 35,600 41,2005000 32,600 42,600 44,300 52,0006000 37,100 50,400 52,400 62,8007000 58,300 61,000 73,7008000 63,200 66,000 84,500______________________________________
The foregoing provides a summary of the general utilitarian and structural aspects of this invention, while the following renders a description of the preferred embodiment of the earth anchor in structure, and in its various modified forms.
BRIEF DESCRIPTION OF THE DRAWING
In the drawing, FIG. 1 provides isometric view of the earth anchor of this invention;
FIG. 2 furnishes a plan view of the earth anchor of this invention, as shown in FIG. 1;
FIG. 3 furnishes a side view of the helical blade for the earth anchor of this invention;
FIG. 4 provides a partial elevational view of a top section of the earth anchor of this invention, having a coupling means securing into its bottom end;
FIG. 5 furnishes a partial elevational view of an extension portion for the earth anchor of this invention having a coupling means securing to its lower end;
FIG. 6 provides a partial elevational view of an earth anchor section of this invention, having a coupling means being securing to its lower end;
FIG. 7 discloses a partial elevational view of the top section of an earth anchor of this invention, having an end cap being mounted into its upper end, while a coupling means is securing to its lower end;
FIG. 8 discloses a modification to the earth anchor of this invention wherein a shank portion contains a series of spacedly mounted helical blades along its length;
FIG. 9 provides a plan view of the upper end cap of the earth anchor of this invention having reinforcing rods connected therewith; and
FIG. 10 furnishes a side view of the upper end cap supported reinforcing rods for the earth anchor of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In referring to the drawing, and in particular FIGS. 1 through 3, there is shown the basic configuration for the earth anchor A of this invention, and which incorporates a shank portion 1 having a helical blade 2 secured therewith. The helical blade, in the preferred embodiment, is designed to different sizes, and can be as small as four inches in diameter, or extend in width to approximately fifteen inches or more in diameter. And, depending upon the size of the blade for the anchor, the thickness of metal used in the formation of the blade can vary between 3/8 inch thick for the smaller sizes, and up to 1/2 inch thick material for the larger diameter anchor. Obviously, other sizes than those stated can be employed. Generally, the pitch between flights for the leading cutting edge 3 to its trailing edge 4 is always somewhere in the vicinity of three inches, so as to provide sufficient clearance for the earth being cut to pass between these spaced edges, and at the same time to furnish that pitch to the leading edge of the blade that provides for a smooth transition in its cut into new soil, preferably without binding or exerting too great of a stress upon the blade, and to at least dig in sufficiently into the earth so as to make some headway for the anchor as it turns into the ground.
The unique feature of this invention is shown more specifically in FIG. 2, and therein it can be seen that the leading cutting edge of the helical blade is formed of a linear design, as shown at 3, with said cutting edge being beveled, on approximately a 30° bevel, down to its sharpened edge, so as to assure a constant penetration into the earth as the anchor is forcefully turned. And as shown, a significant lag angle is formed between the radius from the shank portion 1, in its attachment with the frontal tangent of the said shank portion, so that this cutting edge may conveniently sever the earth in a slicing fashion as the anchor is turned forcefully into the same, while at the same time, should any debris, rock or related type obstacle be encountered by the blade during its turning, there is a good likelihood that such material will gradually be urged outwardly of the blade, beyond its perimeter, and be cleared due to the presence of this lag angle designed into the positioning of its cutting edge for the helical blade. As can be seen, this angle may be in the vicinity of 45° as shown, although angles to a slightly lesser angular degree may yet work sufficiently effective for the anchor of this design during its application.
It is also to be noted of some importance that this leading cutting edge 3 of the anchor is of the identified linear design, provides a length of cutting edge for cutting directly into the ground, and is quite distinct from those cutting edges normally employed upon the helical type anchor where the cutting usually is formed along an increasing radii as the blade extends away from its supporting shank, particularly as shown in the identified prior art as previously analyzed.
Various modifications and structural embodiments to accomodate varying usages of the anchor of this invention have been designed, and all of these modifications are intended to compliment the usage of the basic anchor depending upon its type of application. For example, and as shown in FIG. 4, the anchor section to be seen in this design comprises the helical blade 5, of the identical design as previously analyzed, having its shank portion 6 extending downwardly therefrom. The lower end of the shank portion incorporates an internal cavity, as at 7, and into which a coupling means 8 may be inserted and affixed by means of a pin (not shown) that may slidingly insert through both the said portion 6 and the reduced diameter part 9 that fits within the cavity 7 of the anchor. A collar 10 separates the reduced portion 9 of the coupling means from its further reduced portion 11 arranged downwardly therefrom, and the collar is designed to act as a spacer between anchor portions that are actually fitted together so as to increase the length of the anchor, all which depends upon the nature of use of the anchor, and the force that it has been designed to accommodate, whether it be a tension or compression type of load. For example, if the anchor is to fix a guy wire from a utility pole to the ground, obviously the force to be applied thereon is always in the nature of a tension force, whereas should the anchor be used to act as a support for a pile, then naturally compressive forces will always be exerted upon the same. The anchor has also been designed, as for example as seen in the data set forth in the summary of this invention, for holding this strength in compression, as when the anchor is used in support of a pile or other foundation, and must carry a significant weight in compression.
The upper part 12 of the earth anchor as shown in FIG. 4 is of slightly increased diameter, and functions in the nature of an upper terminus for the said anchor. Usually, some form of an end cap, as will be subsequently described, will be mounted and fastened to the upper end of this part 12 so as to cap off the anchor after it has been affixed into the ground.
Another attribute of this invention is the linking of anchor sections together, and more specifically the connection of the shank portion of one anchor with another, so as to increase the length of the earth anchor, and add to the number of helical blades to be embedded within the ground, all for the purpose of enhancing the strength retention factor of the anchor when installed. And, in certain instances, it may be desirable to utilize linking members or extensions between anchors, and such is shown in FIG. 5. In this embodiment, the plain extension 13 is shown, having a coupling means 14 as previously described connecting into its bottom end, which has a hollow cavity therein, as previously analyzed, while the upper end of the linking member or extension is designed in similar fashion, having an aperture, as at 15, provided therethrough, into which one of the pin means (not shown) as previously described may insert through, and also through any coupling means inserted therein, so as to lock the coupling means and the extension together.
Various lengths of helical extensions incorporating the blade 16 of this invention have been designed, and are conveniently provided for linking together so as to form the length of anchor as previously described. Such is shown in FIG. 6, and it can be seen that each extension 17, or length of its shank portion has at least one helical blade integrally secured thereon, with the blade being of the design as previously described with respect to prior figures analyzed in this disclosure. The upper end of the portion 17 contains a hollow cavity therethrough, as at 18, with an aperture 19 formed through its walls so as to accommodate in a connecting fashion one of the coupling means 11 and 14 as previously described. A locking pin, as stated, inserts therethrough for holding these two members together. The bottom end of the shank portion 17 also has a cavity formed therein, or this cavity, as at 18, may extend all the way through the shank portion as can be seen. But, in those designs where it is desirable to add to the reinforcement of the anchor, these cavities may be only to that depth that will accommodate the parts 9 or 11 of the coupling means therein, with the rest of the shank being of solid configuration so as to enhance their strength, and increase their ability to withstand the significant foot-pounds of torque that are exerted upon them while turning of an anchor forcefully into the ground.
As can be seen in FIG. 7, the earth anchor of this design is very similar to that which was previously described in FIG. 4, but that the end cap 20 is shown in its relationship where it can slidably insert into the cavity 21 provided within the member 12, and therein be secured by means of a pin or other fastening means through the series of apertures 22 and 23 for rigidly securing said cap onto its anchor. The cap may include a lug or other form of integral eyelet 24 and through which a cable connection may be made as when the anchor is readied for usage.
A further modification to this invention is shown in FIG. 8, wherein the shank portion 25 is of some length, and contains a series of spacedly arranged helical blades 26 along its length. Thus, an anchor of this design may be turned forcefully into the ground, and rigidly hold therein due to the multitude of blades that grasp the ground in which the anchor is inserted so as to secure it and function to withstanding excessive compression or tension forces depending upon the application of this anchor. And, the bottom of the anchor may be pointed, as at 27, so as to facilitate the initial penetration of the anchor into the ground and at least to that depth where the lower helical blade can initiate digging and penetration of the ground during the anchor's turning by means of a motor, vehicle, or the other usual instrumentation used to achieve such. And, should additional heighth be desired for the anchor shown in FIG. 8, then other extensions, such as those shown in either FIGS. 4, 5, 6, or 7 may be connected onto the top of the shank portion 25 of the anchor shown so as to lengthen it to that length desired and previously determined to meet design parameters and as necessary to furnish the type of anchor support required for the particular situation encountered. Hence, a plurality of earth anchor extensions as shown in FIG. 6 may be actually linked together, onto the top of the anchor shown in FIG. 8, before one of the end cap sections as previously explained in FIG. 4 or 7 are connected to furnish the upper terminus for the fabricated anchor.
Another modification to the anchor of this invention as shown in FIGS. 9 and 10, and this particular style of structure is intended as a replacement for the type of end cap 20 previously analyzed in FIG. 7. In this particular design, the end cap 28 has an integral upper plate 29, as previously shown, and instead of having a lug connected thereon, a series of reinforcing or other rods 30 are welded or otherwise connected thereupon so that the end cap when emplaced upon the embedded anchor disposes its rods preferably approximate to the bottom of the cavity into which concrete is to be poured for forming a foundation, footing, or even a concrete pile for a more larger building structure. While heretofore it was of customary design to drive wood piling into an excavated site for providing support for the foundation of a building, it can be seen from the data chart depicting the compressive forces to be withstood by the earth anchors therein identified that such anchors can easily replace the customary wood pilings. The reason for this is that the helical blades of the anchor provide significant holding force for the same when embedded within the ground, whereas the wood pilings normally driven into the ground contain no such means for resisting movement of the soil after its emplacement. And, once the earth anchor as used as a helical pile through the teachings of this invention is located, then one of the modified end caps 28 having the integral reinforcing bars thereon may be located upon the upper end of the embedded anchor, and therein function to act as a means for retention of the poured concrete and to provide a footing in and of itself for the concrete foundation, footing, or other piling as poured thereon.
Other modifications to the earth anchor of this invention may occur to those skilled in the art upon reviewing this subject matter of this disclosure. Any such modifications, if within the spirit of this invention, are intended to be encompassed within and protected by any claims to patent protection issuing hereon. The description of the preferred embodiment as set forth herein is done so for illustrative purposes only. | In an earth anchor for use for embedding within the ground and to acquire a secure and snug retention therein, the anchor incorporates a shank portion having a helical blade affixed thereto, the blade having a linear cutting edge positioned at a lagging angle off the perpendicular or radius from the said shank portion; said shank portion may contain one or more of the helical blades spacedly arranged there along, or have a series of shank portions that are connectible axially together to form an anchor of greater length. An end cap is designed for mounting onto the upper end of an anchor, and having reinforcing rods secured thereto, and which may act as reinforcement for a concrete pile, foundation, or the like, as poured thereon, with the anchor providing a firm base for this type of constructed structure. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a device for fastening tubes and tubular objects and includes a C-shaped mounting rail having an elongate opening, and a retaining plate having a through-bore extending transverse to a plane of the retaining plate and provided with an inner thread, a width measured in a direction parallel to the retaining plate plane and corresponding at most to a width of the elongate opening of the mounting rail, and a length measured transverse to the width direction and which is greater than the width of the elongate opening.
[0003] 2. Description of the Prior Art
[0004] Fastening devices of the type described above find particular application for suspending and bracing of objects such as, e.g., tubes and the like. To this end, a mounting rail having an elongate opening is secured to a constructional component or part, e.g., with several segment anchors. For fastening a fastening element, a retaining plate is inserted into the interior of the mounting rail through the rail elongate opening and is pivoted by an angle, e.g., 90° and engages, from behind the free ends, so-called retaining projections. For securing a fastening element, e.g., a threaded rod, the retaining plate has a through-bore provided with an inner thread that form-lockingly engages a complementary outer profile provided at least on a portion of the fastening element. In order to insure the insertion of the retaining plate through the elongate opening, the width of the retaining plate corresponds at most to the width of the elongate opening provided in the mounting rail. The engagement of the retaining projection of the mounting rail by the retaining plate is insured by having the length of the retaining plate, which is measured transverse to the width direction of the retaining plate, greater than the width of the elongate opening.
[0005] German Patent DE 38 11 794 C2 discloses a fastening device including a C-shaped mounting rail and non-circular retaining part which is formed, e.g., as a cast part.
[0006] The drawback of the known device consists in that for producing the retaining part, a lot of material is spent in order to obtained the desired dimensions, which adversely affects the economy of the production.
[0007] A further drawback consists in that the excessive weight of the retaining part increases the overall weight of the fastening device, in particular, when several retaining plates are required.
[0008] Accordingly, an object of the invention is a fastening device including a retaining plate that can be economically produced and has a reduced weight.
[0009] Another object of the invention is a fastening device including a retaining plate that would insure a high stability and would exhibit a good performance under tension loads.
SUMMARY OF THE INVENTION
[0010] These and other objects of the present invention, which will become apparent hereinafter, are achieved by providing, in the device of the type described above, a retaining plate having at least one web on a side of retaining plate adjacent to the elongate opening of the mounting rail. The web provides for stiffening the retaining plate and for its positioning with respect to the mounting rail.
[0011] Providing a stiffening and positioning web permits to form a plate with less consumption of the material and that would weigh less than a conventional retaining plate. At least one web further insures a reliable positioning of the used fastening element. The at least one web defines an additional space for receiving the fastening element and which extends coaxially with the inner bore of the retaining plate. This permits to use fastening elements which do not have a precise length.
[0012] At the same time, the retaining plate according to the present invention occupies less space in the mounting rail than a cast plate or a plate formed of a sheet metal and provide with a reinforcement on its top for increasing its stability.
[0013] Advantageously, there are provided two, arranged parallel to each other, stiffening and reinforcing webs. The webs dependent on the requirements, can have different cross-sections such as, e.g., round, rectangular or the like cross-sections. The dimensions of the webs depend on the space available for the fastening device.
[0014] Advantageously, the two webs are provided on opposite sides of the inner thread which insures an optimal stability in the region of the inner thread as the thread causes weakness of the plate in this area.
[0015] Advantageously, the retaining plate has a U-shaped profile, with the free ends of the profile forming the webs. This shape proved to be optimal for reducing the material consumption and the production costs.
[0016] The webs are advantageously provided, on sides of the inner thread, with beads, which reduces overload in the region of the inner thread. In fastening devices which are subjected to a load in their foreground, the webs are wave-shaped over their entire length, which increases their stability. In addition, the beads function as predetermined bending points, protecting the mounting rail and, thus, the fastening device from an overload.
[0017] To provide for its economical manufacturing, the retaining plate has a uniform wall thickness.
[0018] Advantageously, a side of the retaining plate remote from the elongate opening projects, at least in a region of the inner thread, beyond a remaining region of the remote from the elongate opening, side of the retaining plate. This insures an adequate axial extent of the inner thread, on one hand, and, on the other hand, minimizes the height of the webs in the axial direction of the inner thread.
[0019] An axial extent of the inner thread advantageously corresponds to about 1.5-4.5 times, preferably, to 2.25 times of the wall thickness of the retaining plate.
[0020] Advantageously, the retaining plate is formed as a stamped bent part, which insures its economical manufacturing.
[0021] Advantageously, the mounting rail is provided, at its free edges, with recesses a width of which at least corresponds to a wall thickness of the retaining plate, and wherein the stiffening and positioning webs of the retaining plate engage in the recesses. At least one of the retaining plate webs engages in a corresponding recess. This reduces displacement of the retaining plate in the longitudinal direction of the mounting plate under forces acting in the longitudinal direction of the mounting rail. The distance between separate recesses, which are provided at the free edge, advantageously corresponds to the dimensions of the retaining plate. The recesses preferably have a rectangular cross-section in the longitudinal direction.
[0022] The novel features of the present invention, which are considered as characteristic for the invention, are set forth in the appended claims. The invention itself, however both as to its construction and its mode of operation, together with additional advantages and objects thereof, will be best understood from the following detailed description of preferred embodiments, when read with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The drawings show:
[0024] [0024]FIG. 1 a cross-sectional view of a fastening device according to the present invention with a longitudinal extending, fastening element;
[0025] [0025]FIG. 2 a plan view of a retaining element shown in FIG. 1;
[0026] [0026]FIG. 3 a cross-sectional view of the retaining element taken along line III-III in FIG. 1;
[0027] [0027]FIG. 4 a cross-sectional view of the retaining element taken along line IV-IV in FIG. 2;
[0028] [0028]FIG. 5 a plan view of a retaining element with beads;
[0029] [0029]FIG. 6 a plan view of a another embodiment of a retaining element for a fastening device shown in FIG. 1; and
[0030] [0030]FIG. 7 a cross-sectional view of the retaining element along line VII-VII in FIG. 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] A fastening device according to the present invention, which is shown in FIG. 1, has a C-shaped cross-section and includes a mounting rail 3 provided with an elongate opening 2 , and a retaining element or plate 1 .
[0032] The elongate mounting rail 3 , which is shown in FIG. 1, has a substantially C-shaped cross-section and is formed, preferably, of a single strip of a galvanized or stainless metal sheet.
[0033] The mounting rail 3 has a rear wall 4 and two side walls 5 a and 5 b provided at opposite longitudinal sides of the rear wall and extending substantially perpendicular to the rear wall 4 . At their free front ends, the side walls 5 a , 5 b are bent inward at a substantially right angle and form two webs 6 a and 6 b extending parallel to the rear wall 4 . The webs 6 a , 6 b form the elongate opening 2 which extends in the longitudinal direction L of the mounting rail 3 . The sides of the webs 6 a , 6 b adjacent to the rear wall 4 can be provided with the straight knurls 7 a , 7 b , respectively.
[0034] The retaining plate 1 has a through-bore 8 extending transverse to the plate plane and provided with an inner thread 9 , as particularly shown in FIGS. 2 - 4 . The through-bore 8 is designed for receiving a fastening element, in particular a bolt 12 provided with an outer thread 11 , as shown in FIG. 1 and FIG. 5. The retaining plate 1 has, in a direction parallel to the plate plane, a width b1 that approximately corresponds to the width b2 of the elongate opening 2 , and has, transverse to its width dimension, in the direction parallel to the plate plane, a length c that is greater than the width b2 of the elongate opening 2 . The retaining plate 1 has a uniform width d.
[0035] The U-shaped retaining a plate 1 has at its side 13 adjacent to the opening 2 , two stiffening and positioning webs 14 a , 14 b which form free legs, as particularly shown in FIG. 4. The webs 14 a , 14 b extend in the longitudinal direction of the retaining plate 1 perpendicular to its side 13 adjacent to the elongate opening 2 , and have a height f.
[0036] Dependent on the dimensions and on the use of the fastening means that cooperates with the retaining plate 1 (e.g., of the bolt 12 ), the webs 14 a , 14 b can project, regionwise, beyond bearing areas 15 a , 15 b . The web elevation 14 c , which serves regionwise as stiffening and positioning means, represents a modification of the retaining plate 1 and is shown in FIG. 1 with a dot-dash line. The axial extent f 1 of the web elevation 14 c and the wall thickness d of the retaining plate 1 in this case is greater than the height h that corresponds to the distance between the bearing areas 15 a , 15 b and the outer side 16 of the retaining plate 1 . The side 16 of the retaining plate 1 remote from the opening 2 , projects, in the region of the inner thread 9 , beyond the remaining region of the side 16 , as particularly shown in FIGS. 3 and 4. An axial extent e of the inner thread 9 corresponds approximately to 2.25 times of the wall thickness d. The retaining plate 1 can be formed, e.g., as a stamped bent part.
[0037] The bearing regions 15 a , 15 b have, preferably, a straight knurl 18 a , 18 b , respectively, engageable with a respective straight knurl 7 a , 7 b provided on the free ends of webs 6 a , 6 b of the mounting rail 3 .
[0038] In the embodiment shown in FIG. 5, the webs 14 a , 14 b have additionally two beads 17 surrounding the inner thread 9 . The beads 17 serve, on one hand, for stabilizing the inner thread 9 and, on the other hand, as overload protection means for the fastening device. When a two high load p acts on the fastening element, in particular, on the bolt 12 , the retaining plate 1 would bulge in the region of the beads 17 . The overload protection prevents failure of the entire fastening device at an unpermissible high load p acting on the device.
[0039] Contrary to the retaining plate 1 shown in FIGS. 2 and 5, the retaining plate 21 , which is shown in FIG. 6, has only one circumferential web 22 provided on the side 13 of the retaining plate 21 adjacent to the elongate opening 2 . A straight knurl in the bearing areas 15 a , 15 b of the retaining plate 21 is eliminated in this embodiment of the retaining plate.
[0040] [0040]FIG. 7 shows a web 6 a of the mounting rail 3 a free edge of which, as well as the free edge of the web 6 b , have, instead of a knurling surface, a toothing 23 . The width k of separate indentations of the toothing 23 only slightly wider than the width d of the retaining plate 21 . The spacing between the separate indentations of the toothing 23 corresponds to the dimension b1, so that the web 22 can engage in this indentations to retain the retaining plate 21 against forces which act in the longitudinal direction of the mounting rail 3 .
[0041] Though the present invention was shown and described with references to the preferred embodiments, such are merely illustrative of the present invention and are not to be construed as a limitation thereof and various modifications of the present invention will be apparent to those skilled in the art. It is therefore not intended that the present invention be limited to the disclosed embodiments or details thereof, and the present invention includes all variations and/or alternative embodiments within the spirit and scope of the present invention as defined by the appended claims. | A device for fastening tubular objects includes a C-shaped mounting rail ( 3 ) and retaining plate ( 2 ) having a threaded through-bore ( 8 ), with the width (b1) measured in a direction parallel to the retaining plate plane and corresponding at most to a width (b2) of the elongate opening ( 2 ) of the mounting rail ( 3 ), a length (c) measured transverse to the width direction and which is greater than the width (b2) of the elongate opening ( 2 ) of the mounting rail ( 3 ), and at least one web ( 14 a , 14 b ; 22 ) provided on its side adjacent to the elongate opening formed in the mounting rail. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates generally to surgical instruments. In particular, the present invention relates to a method and instrument for harvesting a section of a blood vessel from a patient.
In certain surgical procedures, it is necessary to remove a section of a blood vessel from a patient for use in another part of the patient's body or for transplanting into a second patient's body. For example, a section of the saphenous vein may be removed for use in coronary bypass surgery. Previously, it has been necessary to make an incision along the full length of the vein section to be removed. The vein is then freed by severing and ligating the branches of the vein, after which the section of the vein can be removed from the patient. The full length incision must then be closed, for example by suturing or staples. Obviously, the harvesting of the vein in this manner leaves disfiguring scars which are cosmetically undesirable. Additionally, the large incision creates a risk of infection to the patient and may not heal properly, especially with those patients who have poor circulation in their extremities. Such an incision may create a chronic wound which will not heal.
Devices for harvesting a section of a blood vessel without creating a full length incision have been suggested. U.S. Pat. No. 4,793,346 to Mindich discloses a device for harvesting a section of a blood vessel by making only small incisions at opposite ends of the blood vessel section. The device includes a guide rod which fits inside of the vein section and a tube having an inner diameter slightly larger than the outer diameter of the vein section to be harvested. The tube has one or more knife blades at the leading edge which are connected to an electrical supply. The vein section is removed by making the incision sufficiently deep so as to expose the ends of the blood vessel section to be harvested. The blood vessel is cut to expose one end, the guide rod is inserted inside the blood vessel section, and the tube is placed over the end of the blood vessel section to be removed. The tube is then pushed along the blood vessel (into the patient) while rotating the tube to sever the branches of the blood vessel with the knife blades mounted at the leading edge of the tube. Electrical current is supplied to the knife blades to heat the blades and thereby cauterize the ends of the severed branches of the blood vessel. The procedure is continued until the tube has reached the second of the two incisions. The blood vessel is exposed and cut from the patient at the second incision, and the tube is then removed from the patient with the blood vessel section inside of the tube. The blood vessel section is then removed from the tube for further treatment and used as desired.
UK Patent Application GB 20 82 459A discloses a device for harvesting a section of a blood vessel similar to that disclosed in the Mindich patent. Again, two incisions are made, one at each end of the blood vessel section to be harvested. A guide rod is inserted into the blood vessel section through one of the incisions and a tube having a cutting element at its operative end is passed over the blood vessel section and guide rod assembly. The tube is rotated as it passes over the blood vessel section to sever the connecting branches. After the tube has passed the entire length of the blood vessel section, the section is cut away through the second incision and the tube is removed from the patient with the harvested section inside the tube.
The blood vessel harvesting devices of the prior art have certain distinct disadvantages. While the prior art devices eliminate the need for a full length incision to remove the blood vessel segment, two incisions, one at each end of the segment to be harvested, are required in order to remove the blood vessel segment. For patients likely to develop chronic wounds, each additional incision increases the risk to the patient, and it is desirable to keep such incisions as close to the patient's trunk as possible and to minimize the number and size of such incisions. Additionally, the prior art devices do not allow for the viewing of the dissection of the blood vessel segment. The physician operating the removal device is unable to see the progression of the dissection and must rely on the guide rod inserted within the blood vessel to guide the cutting instrument in the proper direction. The inability to view the dissection directly increases the risk of damaging the blood vessel segment and the risk of causing injury to the patient.
In addition, it is critical that the segment of blood vessel being harvested is handled with great care since it is destined for reuse (e.g., as an arterial bypass). The blind insertion of a guide rod into the blood vessel damages and likely destroys the endothelium of the vessel. The prior art devices also have the disadvantage of being unable to adequately close off severed branches of the blood vessel and thus are unable to adequately control bleeding. As a result, the patient suffers greater blood loss than is necessary. The prior art devices also may remove more tissue than is necessary because the size of the cutting device is not readily adaptable to changes in the size of the blood vessel.
There is a need for an efficient and effective means for harvesting a section of a blood vessel from the body of a patient. Specifically, there is a need for a device that does not require insertion of any component within the vessel being harvested, and that allows direct viewing of the dissection of the blood vessel segment while at the same time minimizing the size of the incision into the patient's body. Such a device would allow the physician to be much more precise in this procedure, minimize the risk of the patient developing a chronic wound that will not heal, minimize the amount of scarring to the patient's body and maintain the internal integrity of the blood vessel being harvested.
SUMMARY OF THE INVENTION
The present invention is a device and method for harvesting a section of a blood vessel from a patient's body. The invention includes an endoscope of the type having a scope body with a lumen extending longitudinally therethrough, with the lumen having a proximal end and a distal end. The endoscope includes means for viewing an area adjacent to the distal end of the lumen. The lumen has a lateral dimension of size sufficient to accommodate a blood vessel and at least one tool for use in harvesting the blood vessel.
This endoscope for harvesting a blood vessel is relatively uncomplicated. The endoscope allows a section of a blood vessel to be removed by making only a small incision at one end of the blood vessel section to be harvested. The incision exposes a first end of the blood vessel section to be harvested and the first end is inserted through the lumen of the endoscope. The blood vessel is then dissected away from surrounding connective tissue of the patient's body with a dissecting tool inserted through the lumen of the endoscope, using the viewing means to view the dissection in process as the endoscope is advanced along the blood vessel into the patient's body.
In one preferred embodiment, the endoscope is used with a tool for ligating and cutting branches of the blood vessel segment or a second end of the blood vessel segment. The tool has a distal operative tip with means on the distal tip for applying a ligation clip to a section of the blood vessel specimen which is to be sealed. There are also means on the distal tip for cutting the blood vessel segment between the clip and the first end of the blood vessel segment. The tool eliminates the requirement of making a second incision at the second end of the blood vessel segment to cut the blood vessel segment at the second end so that it may be removed.
The endoscope is ideally suited for patients likely to develop chronic wounds, such as diabetics or other persons with poor circulation, because only one small incision is required to remove the blood vessel segment. The endoscope also allows the physician to directly view the dissection of the blood vessel segment. The ability to directly view the dissection allows the physician to conduct the vessel harvesting procedure much more efficiently and precisely, minimizing the risk of damage the blood vessel and minimizing the risk of injury to the patient.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will further be described with reference to the accompanying drawings where like numbers refer to like parts in several views, and wherein:
FIG. 1 is a perspective view of the inventive endoscope and some related tools, along with a portion of a patient's leg;
FIG. 2 is a side elevational view of a dissecting tool of the present invention, with its distal end enlarged in perspective;
FIG. 3 is a side elevational view of a gripping tool of the present invention, with its distal end enlarged in perspective;
FIG. 4 is a side elevational view of a ligation-cutting tool of the present invention, with its distal end shown enlarged in perspective;
FIG. 4A is a top plan view of the distal end of the ligation-cutting tool of FIG. 4;
FIG. 4B is a side elevational view of the distal end of the ligation-cutting tool of FIG. 4;
FIG. 5 is a side elevational view of a side-biting ligation-cutting tool of the present invention, with its distal end enlarged in perspective;
FIG. 6 is a side elevational view of a suction-coagulator tool of the present invention;
FIG. 7 is an enlarged perspective view of the endoscope of the present invention;
FIG. 8 is a perspective view of the endoscope of the present invention, showing its two-part assembly;
FIGS. 9-13 are enlarged perspective illustrations showing the distal end of the inventive endoscope and the tools of FIGS. 2-6 in use during the harvesting of a blood vessel; and
FIG. 14 illustrates the partial removal of a partially dissected blood vessel through a second incision, when a long continuous segment of blood vessel is desired to be dissected from the patient's body.
While the above-identified drawing figures set forth one preferred embodiment of the invention, other embodiments are also contemplated, as noted in the discussion. In all cases, this disclosure presents the present invention by way of representation and not limitation. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art which fall within the scope and spirit of the principles of this invention. It should be specifically noted that the figures have not been drawn to scale as it has been necessary to enlarge certain portions for clarity.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is a device and method for harvesting a section of a vessel from a patient's body for use in another part of the patient's body or for transplanting into a second patient's body. For example, a section of the saphenous vein may be removed for use in coronary bypass surgery. The blood vessel needs to be removed without undue damage to the blood vessel, as well as with minimal damage and trauma to the patient. Although the description herein is directed to the harvesting of the saphenous vein, it is contemplated that the present invention be used in connection with the efficient and effective harvesting of the other lumens and vessels from a patient's body.
THE TOOLS
In FIG. 1, a saphenous vein 20 (shown in phantom) and endoscope 30 are shown. The saphenous vein 20 travels along the medial side of the foot, leg, and thigh, where it joins with the femoral vein near the groin.
When used to harvest a blood vessel, the endoscope 30 is used in conjunction with several tools. A dissecting tool 100 (FIG. 2) is used to separate the blood vessel from the surrounding connective tissue. A gripping forceps 150 (FIG. 3) is used by the physician to hold the blood vessel 20 during the procedure. A ligation-cutting tool 200 (FIG. 4) is used when severing side branches 22 from the blood vessel 20. A side-biting ligation-cutting tool 250 (FIG. 5) is used to transect the blood vessel 20 when the dissection is completed. Finally, a suction-coagulator tool 300 (FIG. 6) is used to control bleeding during the procedure. Each of these tools is described in detail in the succeeding discussions.
As illustrated in FIGS. 1 and 7, the endoscope 30 includes an elongated scope body 34 and a handle 36. A lumen 38 extends longitudinally through the scope body 34 and has a cross-sectional shape which is substantially elliptical. The lumen 38 is of a size large enough to accommodate the blood vessel 20 which is to be harvested and one or more of the tools 100, 150, 200, 250 and 300 longitudinally therein. In one embodiment, the size of the lumen 38 in the scope body 34 is 2 cm wide by 1 cm deep in an elliptical shape, while the scope body 34 itself is 30 to 90 centimeters long. Each of the tools is at least 2 cm longer than the scope body 34. As illustrated in FIG. 8, the scope body 34 of the endoscope 30 is selectively securable to the handle 36. The scope body 34 can thus be made as a disposable unit to eliminate problems with re-sterilization of the portion of the endoscope 30 that enters the patient's body. After use, the endoscope is disassembled, the scope body 34 disposed of, and the handle 36 (containing power connections, lighting means, etc.) saved for repeated use with a new scope body. Alternatively, the scope body has a longitudinal channel therein for reception of the viewing and illumination portions of the endoscope, so that those components are reused while the scope body is disposed after each use. The scope body is provided in a variety of lengths and sizes (cross-sectional) to accommodate patients of different sizes and different blood vessel lengths.
As seen in FIG. 7, fiber optics illumination source 40 and a fiber optics viewing device 42 are located at the distal end of the endoscope 30 and positioned adjacent each other such that the area immediately adjacent the distal end of endoscope 30 can be illuminated and viewed by the physician. When connected to the handle 36, the source 40 is operably connected to an external light source 43 by a suitable light transmission conduit 44 which extends through the endoscope 30. Similarly, the viewing device 42 is operably connected to an external monitor 45 by a suitable image transmission conduit 46 which extends through the endoscope 30. The physician views the area adjacent the distal end of endoscope 30 using the illumination source 40 and the viewing device 42 by use of the viewing monitor 45 (FIG. 1) which is connected to the endoscope handle 36 through the conduit 46. The monitor 45 may take several forms, such as a television monitor or an eye-piece worn by the physician, as is conventional. The endoscope body 34 also has an irrigation channel 48 extending therethrough. The irrigation channel is operably coupled to an external source of irrigant 49 via a suitable conduit 50. A distal open end of the irrigation channel is positioned adjacent the distal ends of the fiber-optic illumination source 40 and the viewing device 42, as seen in FIG. 1.
Each of the tools 100, 150, 200, 250 and 300 to be used with the endoscope 30 are of a size small enough to fit through the lumen 38 of the scope body 34 while a blood vessel 20 is also in the lumen 38. The tools 100, 150, 200, 250 and 300 are also long enough to allow the physician to comfortably manipulate them through the lumen 38 (i.e., the tools 100, 150, 200, 250 and 300 are longer than the lumen 38).
The dissecting tool 100 (FIG. 2) is used to aid in separating the vessel being harvested from the surrounding tissue. The dissection tool 100 has an elongated shaft 105, with a handle 106 attached to the proximal end of the shaft 105 and an annular dissecting ring 110 attached to the distal end of shaft 105. The dissecting ring 110 is oriented such that a plane defined by the dissecting ring 110 is generally perpendicular to the longitudinal axis of the shaft 105. The size of dissecting ring 110 is large enough to fit over the exterior of the blood vessel 20. The dissecting ring 110 has a rounded distal edge 112 used to separate the blood vessel 20 from the surrounding connective tissue as the dissecting tool 100 is advanced over the blood vessel 20. The dissecting tool 100 is provided in a plurality of sizes for different sizes of blood vessels. Typical sizes for such tools would have inside diameters of 4 mm, 5 mm, and 6 mm.
The gripping tool 150 (FIG. 3) is used to hold and retain the vessel being harvested during the procedure. The gripping tool 150 has an elongated shaft 155, with a handle 156 attached to a proximal end of the shaft 155 and a gripping mechanism 160 attached to a distal end of the shaft 155. The handle 156 is preferably a scissors-type handle to actuate the gripping mechanism 160 at the distal end of the body 158 and includes a latching mechanism 157 which allows the gripping mechanism to be locked in a set position (e.g., in a "gripping" position). The shaft 155 transmits the actuating movement from the handle 156 to the gripping mechanism 160. The gripping mechanism 160 includes a first jaw 162 and a second jaw 164 which oppose each other. When the gripping handle 156 is operated by the physician, the first jaw 162 and the second jaw 164 are moved toward each other and may be used to grip the blood vessel 20 between gripping surfaces 166 and 168 thereon. The jaws 162 and 164 are small enough to fit through the dissecting ring 110 on the dissecting tool 100.
The ligation-cutting tool 200 (FIGS. 4, 4A and 4B) is used to sever and seal side branches on the vessel being harvested. The ligation-cutting tool 200 has an elongated shaft 201, with a ligation clip applicator 202 and a cutting mechanism 204 at the distal end of the shaft 201. The ligation clip applicator 202 includes a first yoke 208 and a second opposed yoke 210. Each yoke 208 and 210 is in turn divided into two sections; each yoke 208 and 210 is forked at its distal end, forming two opposed prongs 212A and 212B on the yokes 208 and 210, respectively. The prongs 212A and 212B on yokes 208 and 210 are parallel to each other and generally aligned with the longitudinal axis of the ligation-cutting tool 200. The yoke 208 and 210 and the prongs 212A and 212B thereon oppose each other and serve to apply ligation clips 216 (see FIGS. 4A and 4B) to a side branch 22 being severed. The opposing prongs 212A and 212B of each yoke 208 and 210 contain grooves 214A and 214B, respectively, to securely hold a ligation clip 216 therein. When the ligation clips 216 are thus held between the opposing prongs 212A and 212B of yokes 208 and 210, the generally U-shaped ligation clips 216 aid the physician in properly aligning the ligation-cutting tool 200 and the side branch 22 to be ligated by providing an abutment for the side branch 22 when the side branch 22 is positioned between the yokes 208 and 210. When the yokes 208 and 210 are biased towards each other in a conventional manner, the ligation clips 216 are deformed to clamp onto the side branch 22 therebetween and the blood flow through the side branch 22 is halted at two slightly spaced apart points (e.g., two clips are applied approximately 0.25 inches apart). When the ligation clip applicator 202 is activated and the yokes 208 and 210 clamp the ligation clips 216 onto the side branch 22, the side branch 22 is also held securely for cutting the side branch 22.
The cutting mechanism 204 on the ligation-cutting tool 200 includes a cutting blade 230 aligned between the prongs 212A and 212B and proximal to the ligation clips 216. The cutting blade 230 is normally retracted (as seen in FIGS. 4, 4A and 4B) to allow the side branch 22 to be positioned properly between the yokes 208 and 210. A cutting edge 232 of the blade 230 faces the distal end of the ligation-cutting tool 200, and the cutting motion of the blade 230 is in a distal direction (e.g., towards the side branch 22). The blade 230 is wide enough to completely sever the side branch 22 between the two yokes 208 and 210. The cutting mechanism 204 is activated by the physician (as described below) after the side branch 22 has been ligated (i.e., the side branch 22 has been clipped shut and blood flow halted) and while the side branch is still held securely in the yokes 208 and 210. After the blade 230 has severed the side branch 22, the blade 230 returns into its original retracted position.
The ligation clip applicator 202 and the cutting mechanism 204 are both actuated by mechanisms at the proximal end of the shaft 201 of the ligation-cutting tool 200. The ligation clip applicator 202 is preferably actuated by a scissors-type handle 220. By squeezing the scissors-type handle 220, the physician causes each set of prongs 212A and 212B on the yokes 208 and 210 to be moved together, thereby compressing their respective ligation clips 216 about the side branch 22 of the blood vessel 20, as described above. The scissors-type handle 220 includes a latching mechanism 222 which serves to secure the handle 220 and thus the ligation clip applicator 202 in a closed or clamped position. While the ligation clip applicator 202 is held in a clamped position, the cutting mechanism 204 is actuated, preferably by a plunger 224 located at the proximal end of the ligation-cutting tool 200. The plunger 224 is operably connected to the cutting blade 230, and biased proximally to urge the blade 230 into its normally retracted position. By moving the plunger 224 distally, the physician causes the cutting blade 230 to likewise move distally and cut the side branch 22 of the blood vessel 20 which is retained between the yokes 208 and 210. When the physician releases the plunger 224, the plunger 224 (and thus the cutting blade 230) retracts to its original position. Manipulation of the handle 220 then separates the prongs 212A and 212B, leaving the clip in place on the severed portions of the side branch 22, and the ligation-cutting tool 200 is removed or relocated for reuse (the clips may be fed into place in the grooves of the prongs from a suitable clip magazine (not shown) to enable multiple ligations without removing the tool from the body).
The shaft 201 of the ligation-cutting tool 200 is a slender member that is longer than the lumen 38 of the endoscope 30. A housing 209 covers those mechanisms on the shaft 201 that transmit the manipulations of the handle 220 and the plunger 224 at the proximal end of the ligation-cutting tool 200 to the clipping and cutting motions, respectively, at the distal end of the ligation-cutting tool 200.
The side biting ligation-cutting tool 250 (FIG. 5) is used to sever and seal the distal end of the vessel being harvested. The side-biting ligation-cutting tool 250 is identical in operation to the ligation tool 200, except that the operative components at the distal end of the tool 250 are oriented generally normally to the axis of the tool 250. As seen in FIG. 5, the side biting ligation-cutting tool 250 has an elongated shaft 251, with a ligation clip applicator 252 and a cutting mechanism 254 at the distal end of shaft 251. The ligation clip applicator 252 includes a first yoke 258 and a second, opposed yoke 260. Each yoke in turn is forked at its distal end, forming two opposed prongs 262A and 262B, respectively. The prongs are aligned generally parallel and each has inner grooves 264 to retain ligation clips between each opposed pair of prongs 262A and 262B. The structure and operation of the ligation clip applicator 252 is similar to that illustrated in FIGS. 4A and 4B for the ligation-cutting tool 200.
The yokes 258 and 260 and the prongs 262A and 262B thereon oppose each other and serve to apply ligation clips (not shown in FIG. 5) to the distal end of the segment of the blood vessel being severed. When the ligation clips are thus held between the opposing prongs 262A and 262B of yokes 258 and 260, the generally U-shaped ligation clips aid in positioning and properly aligning the side biting ligation-cutting tool 250 and the blood vessel to be transected by providing an abutment for the blood vessel when the blood vessel is positioned between the yokes 258 and 260. When the yokes 258 and 260 are moved towards each other, the ligation clips are clamped onto the blood vessel therebetween and the blood flow through the blood vessel is halted at two slightly spaced-apart points (e.g., two clips are applied approximately 0.25 inches apart). When the ligation clip applicator 252 is activated and the yokes 258 and 260 clamp the ligation clips onto the blood vessel, the blood vessel is also held securely for cutting the blood vessel.
The cutting mechanism 254 on the side biting ligation cutting tool 250 includes a cutting blade 280 aligned between the prongs 262A and 262B. Again, the structure of the cutting mechanism for the tool 250 is quite similar to that illustrated in FIGS. 4A and 4B for the ligation-cutting tool 200. The blade 280 is positioned such that a cutting edge 282 of the blade 280 does not interfere with the alignment of the blood vessel between the yokes 258 and 260. The cutting blade 280 is normally retracted (as seen in FIG. 5) to allow the blood vessel to be positioned properly between the yokes 258 and 260. The cutting edge 282 of the blade 280 faces in a transverse direction from the shaft 251 of the side biting ligation-cutting tool 250, and the cutting motion of the blade 280 is in a transverse direction (e.g., toward the blood vessel). The blade 280 is wide enough to complete sever the blood vessel between the two yokes 258 and 260. The cutting mechanism 254 is activated after the blood vessel has been ligated (i.e., the blood vessel has been clipped shut and blood flow halted) and while the blood vessel is still held securely in the yokes 258 and 260. After the blade 280 has severed the blood vessel, the blade 280 returns to its original retracted position.
The primary difference between the tool 200 and tool 250 is that the distal operative portion of the tool 250 is oriented at an angle generally ninety degrees opposed to the axis of the shaft 251 of the tool 250. The yokes 258 and 260 are thus oriented to straddle a blood vessel extending generally parallel to the shaft 251 to apply ligation clips thereto. After clips are applied, the yokes continue to hold the blood vessel to permit severing of the vessel using the blade 280. Other than the revision in orientation of the distal portion of the ligation-cutting tool 250, it operates in the same manner as the ligation-cutting tool 200.
The ligation clip applicator 252 and the cutting mechanism 254 are both actuated by mechanisms at the proximal end of the shaft 251 of the ligation-cutting tool 250. The ligation clip applicator 252 is preferably actuated by a scissors-type handle 270. Squeezing of the scissors-type handle 270 causes each pair of prongs 262A and 262B on the yokes 258 and 260 to move together, thereby compressing their respective ligation clips about the blood vessel. The scissors-type handle 270 includes a latching mechanism 272 which serves to secure the handle 270 and thus the ligation clip applicator 252 in a closed or clamped position. While the ligation clip applicator is held in a clamped position, the cutting mechanism 254 is actuated, preferably by a plunger 274 located at the proximal end of the ligation-cutting tool 250. The plunger 274 is operably connected to the cutting blade 280, and biased proximally to urge the blade 280 into its normally retracted position. By moving the plunger 274 distally, the physician causes the cutting blade 280 to likewise move distally and cut the blood vessel which is retained between the yokes 258 and 260. When the physician releases the plunger 274, the plunger 274 (and thus the cutting blade 280) retracts to its original position. Manipulation of the handle 270 then separates the prongs 262A and 262B, leaving the clips in place on the severed portions of the blood vessel, and the ligation cutting tool 250 is removed.
The shaft 251 of the side biting ligation-cutting tool 250 is a slender member that is longer than the lumen 38 of the endoscope 30. A housing 259 covers those mechanisms on the shaft 251 that transmit the manipulations of the handle 270 and the plunger 274 at the proximal end of the side biting ligation-cutting tool 250 to the clipping and cutting motions, respectively, at the distal end of the side biting ligation-cutting tool 250.
The suction-coagulator tool 300 (FIG. 6) is used to remove body fluids (e.g., blood) and reduce bleeding during the vessel harvesting procedure, and is of the type generally known in the art for this procedure. The suction-coagulator tool 300 has an elongated shaft 301 and includes a handle 310 attached to the proximal end of shaft 301. A suction tube 302 is attached to the proximal end of shaft 301 and extends to the distal end of shaft 301. At the distal end of shaft 301 the suction tube 302 is open for suctioning body fluids. Also attached to the proximal end of shaft 301 is a power cable 304 for supplying power for tissue coagulation. When button 308 on handle 310 is activated, the power is supplied to the distal end of shaft 301 to cauterize bleeding tissue, and thus to stop bleeding. The suction-coagulator tool 300 controls bleeding in two ways. The suction tube 302 may be used alone to suction any body fluids from the dissection area, or the coagulator may be used to cauterize the bleeding tissue.
METHOD OF USE
The endoscope 30 and accompanying tools 100, 150, 200, 250 and 300 are used in combination for harvesting a vessel. After proper preparation of the incision site, the physician makes a small incision 350 (e.g., 3 cm long) over the proximal aspect of the blood vessel to be harvested (see FIGS. 1 and 9). The blood vessel 20 is exposed and dissected for a short length under direct vision. As seen in FIG. 9, the blood vessel 20 is then severed to expose a free end 352 and a free end 353 (which may be clipped as shown in FIG. 9). For example, to remove a saphenous vein, the incision 350 will be made at the groin over the saphenous vein and the vein will be dissected free from the junction of the common femoral vein. As shown in FIGS. 1 and 9, the gripping forceps 150 is inserted through the dissecting ring 110 of the dissecting tool 100, and the assembly of the dissecting tool 100 and the gripping forceps 150 is inserted through the lumen 38 of the endoscope 30 such that the distal ends of the dissecting tool 100 and gripping forceps 150 extend beyond the distal end of the lumen 38. The physician then grasps the free end 352 of the blood vessel 20 with the gripping forceps 150 and holds it under tension. The dissecting tool 100 is then advanced distally (together with the endoscope 30) over the distal end of the gripping forceps 150 and over the blood vessel 20. As the dissecting tool 100 is manipulated by the physician, the blood vessel 20 is dissected away from the surrounding connective tissue.
As illustrated in FIG. 10 (which has a portion of the patient's body broken away to show the invention in operation), the dissection process proceeds distally along the blood vessel 20, and the endoscope 30 is advanced along with the dissecting tool 100 into the incision 350. Until this point, the physician has been viewing the procedure under direct vision. Now, the physician switches to viewing the dissection process (occurring at the area immediately adjacent the distal end of the lumen 38) through the fiber optic viewing device 42 located at the distal end of the scope body 34 of the endoscope 30. The illumination source 40 provides adequate lighting for the physician to view the dissection and tool operations occurring within the patient via the monitor. Irrigant is introduced as necessary through the irrigation channel 48 of the endoscope 30 to keep blood or other body tissue from obscuring vision adjacent the distal end of the scope body 34 of the endoscope.
As the dissection tool 100 is advanced along the blood vessel 20, a side branch 22 of the blood vessel 20 may be encountered before the desired length of blood vessel 20 has been dissected. When the physician reaches a side branch 22 before obtaining the desired length of blood vessel 20, the ligation-cutting tool 200 is employed to sever the side branch 22 from the vessel being harvested (blood vessel 20).
When a side branch 22 is reached, the physician stops advancing the dissecting tool 100 and endoscope 30 and, if necessary, withdraws the dissecting tool 100 proximally from the side branch 22 to provide room for operation of the ligation-cutting tool 200. The ligation-cutting tool 200 is inserted into the proximal end of the lumen 38 and advanced distally through the lumen 38 and into the area distal of the scope body 34 of the endoscope 30. Using the illumination source 40 and the viewing device 42, the physician positions the ligation-cutting tool 200 over the side branch 22 such that the side branch 22 is sitting in the yokes 208 and 210 (see FIG. 11). The physician then manipulates the handle 220 of the ligation-cutting tool 200 to actuate the ligation clip applicator 202. As the prongs 212A and 212B on each of the yokes 208 and 210 move toward each other, the ligation clips 216 are clamped about the side branch 22, thereby stopping blood flow through the side branch 22.
While the side branch 22 is held securely between the yokes 208 and 210 of the ligation clip applicator 202, the physician pushes the plunger 224 to activate the cutting mechanism 204. As shown in FIG. 12, the cutting blade 230 thus moves distally into and through the side branch 22, thereby severing the side branch 22 from the blood vessel 20 between the ligation clips 216. When the plunger 224 is released by the physician, the cutting blade 230 returns to its original retracted position. The handle 220 is then manipulated to separate the prongs 212A and 212B, and the ligation-cutting tool 200 is withdrawn proximally through the lumen 38 of the endoscope 30. The ligation-cutting tool 200 may then be prepared to be used again later in the procedure (i.e., reloaded with additional clips 216), if required.
After the ligation-cutting tool 200 has been removed from the endoscope, the dissecting tool 100 and endoscope 30 are again advanced distally along the blood vessel 20 (as previously described) until another side branch is reached. In this regard, the dissecting ring 110 is large enough to pass over the clipped and severed stumps of any side branches 22 which extend from the blood vessel 20. The ligation-cutting tool 200 is then used as previously described to sever additional side branches from the blood vessel 20. The procedure is repeated until the desired length of blood vessel 20 has been dissected free from the surrounding tissue and side branches. During the dissection procedure, the suction-coagulator tool 300 is used as required to control bleeding, again under the constant vigilance of the physician through the endoscope 30. During the entire procedure, the blood vessel 20 has been held in tension by the physician via the gripping tool 150. In addition, as more and more of the blood vessel 20 becomes dissected, the endoscope 30 is advanced distally into the patient's body and the blood vessel 20 is moved into the lumen 38 of the scope body 34.
When the desired length of blood vessel 20 has been dissected free from the surrounding connective tissue, the dissecting tool 100 is moved proximally away from the distal end of the dissected segment, and the side-biting ligation-cutting tool 250 is inserted into the proximal end of the lumen 38 and advanced distally through the lumen 38 into the area adjacent the distal end of the scope body 34 and the distal end of the dissected blood vessel 20. The side-biting ligation-cutting tool 250 is positioned such that the blood vessel 20 is between the first yoke 258 and the second yoke 260 of the ligation clip applicator 252. When the blood vessel 20 is properly positioned between yokes 258 and 260, the physician manipulates the handle 270 to actuate the ligation clip applicator 252. As the yokes 258 and 260 move toward each other, the yokes 258 and 260 act to pinch the ligation clips 266 over the distal end of the dissected blood vessel 20 (thus stopping blood flow through the blood vessel 20). While the blood vessel 20 is held securely by the ligation clip applicator 252, the physician pushes the plunger 274 to activate the cutting mechanism 254. The cutting blade 280 advances between the ligation clips 266 and through the blood vessel 20 to sever the blood vessel 20 into a freed section 360 having free end 352 (FIG. 10) and a free end 361 (FIG. 13) and a remaining section 362. When the plunger 274 is released by the physician, the cutting blade 280 returns to its retracted position. The handle 270 is manipulated to separate the prongs 262A and 262B, and the side-biting ligation-cutting tool 250 is withdrawn proximally through the lumen 38 of the endoscope 30. The tool 250 may apply ligation clips on sections 360 and 362, or just one clip on the remaining section 362 of the blood vessel 20.
The freed section 360 of the blood vessel 20 is now free of all connections to the patient's body and is substantially within the lumen 38 of the endoscope 30. While gripping the now dissected blood vessel 20 with the gripping forceps 150, the physician may simultaneously remove the scope body 34 of the endoscope 30 and the enclosed segment of blood vessel 20 from the body of the patient. After the endoscope 30 and freed section 360 of blood vessel 20 are removed from the patient, the physician closes the incision 350 in the patient's body to complete the vessel harvesting procedure. The freed section 360 of the blood vessel 20 may then be removed from the lumen 38 of the endoscope 30 and prepared for its intended end use. The vessel harvesting procedure has been accomplished with only a single small incision, yet the physician can see the entire working portion of the procedure for manipulation of the tools to accomplish dissection, ligation and severing of the freed section 360 of the blood vessel 20. This results in less trauma to the patient than was previously attainable, with a much more precise and efficient procedure, both in terms of affecting the tissue surrounding the dissected vessel, and in terms of the timing and control of the procedure by the physician.
Occasionally, it is desired to remove a continuous length of a blood vessel that is longer than the scope body of the inventive endoscope. In this instance, the physician is unable to advance the endoscope and its related tools far enough from the original small incision into the patient to harvest a segment of the desired length. If no endoscope scope body is long enough to harvest a blood vessel segment of the desired length, the physician may make a second incision in the patient adjacent that point on the blood vessel where the dissection has reached via the use of the endoscope and related tools through the first incision. This is illustrated in FIG. 14.
FIG. 14 illustrates a portion of a patient's leg. A first incision 350 has been made in the patient and the blood vessel 20 severed to create free ends 353 and 352. A portion of the desired segment of the blood vessel (to the left of the incision 350 in FIG. 14) has been dissected, ligated and clipped from the surrounding tissue and side branches 22, using the inventive endoscope and tools in a manner as discussed above. The desired segment of the blood vessel (designated as segment 400 in FIG. 14) is not severed using the side-biting ligation-cutting tool 250 through the scope body 34 of the endoscope 30. Instead, a second incision 450 is made in the patient adjacent that point where the dissection of the blood vessel 20 has reached. This second incision thus exposes that portion of the blood vessel 20 which has been dissected from the surrounding connective tissue of the patient's body (segment 400). The physician releases the free end 352 of the blood vessel 20 (which has been continually held by the gripping forceps 150) and proximally withdraws the endoscope 30 and all of its associated tools which are still in the patient's body. Working through the second incision 450, the physician then grips the exposed portion of the blood vessel 20 and pulls the dissected segment 400 of the blood vessel 20 through the second incision, in direction of arrow 455 as illustrated in FIG. 14.
Once the entire dissected segment 400 has been pulled out of the patient through the second incision 450, further dissection of the remaining portion of the blood vessel 20 within the patient can continue using the inventive tools and method. As previously described, the gripping forceps 150 is inserted through the dissecting ring 110 of the dissecting tool 100 and the assembly of the dissecting tool 100 and the gripping forceps 150 is inserted into the proximal end of the lumen 38 and advanced distally through the lumen 38. The gripping forceps 150 is again used to hold the free end 352 of the segment 400 of the blood vessel 20 during the continued procedure. The endoscope 30 and dissecting tool 100 are distally advanced over the blood vessel 20 and into the patient's body through the second incision 450. The physician then continues to dissect the blood vessel 20 away from the surrounding connective tissue with the dissecting tool 100, ligating and severing side branches 22 as they are encountered using the ligation-cutting tool 150. The suction-coagulator tool 300 is also used as necessary during continued dissection and side branch severing. This process may be repeated until the desired length of blood vessel 20 has been harvested. At this point, the side-biting ligation-cutting tool 250 is employed through the second incision 450 and endoscope 30 to sever the blood vessel 20 from the patient in the desired length. The severed blood vessel is then withdrawn, along with the endoscope 30 and any related tools remaining within the patient, from the patient through the second incision 450. The severed blood vessel is removed from the endoscope and then treated as necessary for further use. The incisions 350 and 450 are then closed up, with minimal trauma to the patient. For instance, a two-step vessel harvesting procedure such as illustrated in FIG. 14 may result in the harvesting of a vessel as long as twelve to fifteen inches, with only two separate 3 cm long incisions made in the patient's skin. The entire procedure, as conducted using the inventive endoscope and its related tools, has been conducted under direct vision or endoscopic vision by the physician and is thus much more effective, efficient and elegant than prior vessel harvesting techniques.
CONCLUSION
The present invention permits a discrete segment of a blood vessel to be harvested with only a small incision in the body of a patient (or more than one small incision if a very long segment is desired). The inventive endoscope and its unique tools eliminate the need for a full length incision along the length of the blood vessel in order to harvest a segment of the blood vessel. Use of the inventive endoscope and tools eliminates the need for a second incision at the distal end of the desired segment of the blood vessel in order to sever the desired segment from the patient's body, and also allows vessel harvesting with a relatively small incision. Proximal incisions heal easier and more readily than distal incisions in most patients, and particularly for those with poor circulation in their extremities. The illumination source and the viewing device of the inventive endoscope allow the physician to directly view the dissection in process, which results in a very precise and controlled dissection of the blood vessel. At the same time, the use of the ligation-cutting tool and the side-biting ligation-cutting tool allows the physician to control bleeding by cutting and sealing off side branches to the blood vessel and the vessel itself in a secure and permanent manner. Nothing is inserted within the blood vessel being harvested during the procedure, so vessel integrity is maintained. Accordingly, undesired trauma to the vessel being harvested and to its surrounding connective tissue is minimized.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. | An endoscope for use in harvesting blood vessels includes a scope body of the type having a lumen extending longitudinally therethrough which itself has a proximal and a distal end. The endoscope includes means for viewing an area adjacent the distal end of the lumen, and the lumen has a lateral dimension of a size sufficient to accommodate the blood vessel being harvested and at least one tool for use in harvesting the blood vessel. A first end of the blood vessel section to be harvested is exposed through an incision in the patient's body. A dissecting tool and a gripping tool are inserted through the lumen of the endoscope and used to dissect the blood vessel away from the surrounding connective tissue of the patient's body, using the viewing means of the endoscope to view this dissection in process within the patient's body. Additional tools are provided for use through the lumen of the endoscope to remove body fluids and coagulate bleeding tissue, and to sever side branches from the blood vessel to be harvested, as well as to sever a distal end of the blood vessel to be harvested when a desired length of blood vessel has been dissected. Only a single small incision in the patient's body is necessary to harvest a relatively long length of blood vessel in a precise and controlled manner through endoscopic vision using the inventive endoscope and its related tools.
.Iadd.The questions raised in reexamination request No. 90/004,301, filed Jul. 12, 1996, have been considered and the results thereof are reflected in this reissue patent which constitutes the reexamination certificate required by 35 U.S.C. 307 as provided in 37 CFR 1.570(e). .Iaddend. | 0 |
TECHNICAL FIELD
[0001] The present invention relates to a method for preparing natural killer cells (NK cells) having a high cytotoxic activity from hematopoietic precursor cells with high purity and a high expansion factor without using a serum or feeder cells of an animal, and a pharmaceutical composition containing the NK cells obtained by the method.
BACKGROUND ART
[0002] NK cells do not attack normal cells expressing MHC class I molecules but mainly attack cells in which the expression of the MHC class I molecules is reduced or lost. Since the expression of the MHC class I molecules is reduced in cancer cells or cells infected with a virus, NK cells can attack these cells. Therefore, if allogeneic NK cells are used in cell therapy of a cancer or an infectious disease, it is advantageous that there is no need to precedently immunize the NK cells for causing them to recognize target cells, and that an adverse reaction of GVH (Graft-versus-host) disease can be avoided. Actually, according to reports of Miller et al. (Non Patent Literature 1) and Rubnitz et al. (Non Patent Literature 2), when a cancer patient was a recipient and concentrated NK cells obtained from fresh peripheral blood mononuclear cells of a healthy donor closely related to the recipient were transplanted, the transplanted NK cells temporarily survived without causing an adverse reaction in the recipient and retained their cytotoxic activity. There is, however, no report on a clinical trial showing the effectiveness of NK cell transplantation therapy. One of the reasons is that the number of cells collectable from a donor by lymphocyte apheresis is limited, and hence, NK cells in number sufficient for killing target cells, such as cancer cells or cells infected with a pathogen, cannot be caused to stay in the body of a recipient until the target cells are killed. According to, for example, Non Patent Literature 2, a survival period of NK cells is not correlated with the number of administered NK cells, but is merely 2 to 189 days, with a median as small as 10 days. Therefore, in order to cause NK cells in number sufficient for killing target cells, such as cancer cells or cells infected with a pathogen, to stay in the body of a recipient until the target cells are killed, it is necessary to frequently repeat the NK cell transplantation, which is a great burden of the patient. Accordingly, a technique in which NK cells obtained from a donor are once cultured in a test tube to obtain NK cells in number sufficient for killing target cells has been developed. In this technique, use of a serum or feeder cells of an animal is not preferred because a risk of infection is otherwise caused in prepared NK cells.
[0003] Umbilical cord bloods of various blood types are classified and stored in an umbilical cord blood bank, and thus if an umbilical cord blood is used as an origin of NK cells for use in a treatment, it is easy to select, based on the blood type of a patient, an umbilical cord blood of a blood type that has high histocompatibility and low possibility of an adverse reaction caused by the transplantation. Therefore, a technique in which NK cells for use in a treatment are prepared from an umbilical cord blood without using a serum or feeder cells of an animal has recently attract attention. Spanholtz et al. (Non Patent Literature 3) reported that NK cells were prepared in number ten thousand times or more in 6 weeks from CD34-positive cells derived from a cryopreserved umbilical cord blood. It cannot be said, however, that the cytotoxic activity of the NK cells obtained by the method of this report is high. Besides, in the conventional technique, for the preparation of NK cells from hematopoietic precursor cells, it is necessary to replace, during the preparation, a medium with one having a different cytokine composition.
CITATION LIST
Non Patent Literature
[0004] Non Patent Literature 1: Miller, J. S. et al., Blood, 105: 3051 (2005)
[0005] Non Patent Literature 2: Rubnitz, J. E. et al., J. Clin. Oncol., 28: 955 (2010)
[0006] Non Patent Literature 3: Spanholtz et al., PLos ONE, 5: e9221 (2010)
SUMMARY OF INVENTION
Technical Problem
[0007] Accordingly, it is necessary to develop a technique in which NK cells having a high cytotoxic activity can be prepared with high purity, without using a serum or feeder cells of an animal, from hematopoietic precursor cells including hematopoietic precursor cells derived from an umbilical cord blood or an adult blood cell tissue, and hematopoietic precursor cells prepared from induced pluripotent stem cells, embryonic stem cells, adult stem cells or the like. Besides, in order to simplify operation procedures, it is necessary to develop a simpler culturing condition for preparation of hematopoietic precursor cells. Furthermore, it is also necessary to develop a simpler culturing condition for preparing NK cells from the hematopoietic precursor cells.
Solution to Problem
[0008] The present invention provides a method for preparing NK cells. The method for preparing NK cells of the present invention includes the steps of expanding hematopoietic precursor cells under a single culturing condition; and differentially inducing the cells obtained in the expanding step into NK cells.
[0009] In the method for preparing NK cells, a medium used in the step of expanding hematopoietic precursor cells under a single culturing condition may be supplemented with IL-15, SCF, IL-7 and F1t3L in some cases.
[0010] In the method for preparing NK cells, the medium used in the step of expanding hematopoietic precursor cells under a single culturing condition may be supplemented further with TPO in some cases.
[0011] In the method for preparing NK cells, the step of differentially inducing the NK cells may include culturing the expanded hematopoietic precursor cells under a culturing condition containing IL-2 in some cases.
[0012] In the method for preparing NK cells of the present invention, the medium used in each of the steps may be supplemented with a human AB-type serum and/or a human serum albumin in some cases.
[0013] In the method for preparing NK cells of the present invention, the hematopoietic precursor cells may be at least one of hematopoietic precursor cells selected from the group consisting of hematopoietic precursor cells contained in an umbilical cord blood and/or an adult blood cell tissue, hematopoietic precursor cells differentially induced from induced pluripotent stem cells, embryonic stem cells and/or adult stem cells, and hematopoietic precursor cells directly converted from differentiated cells in some cases.
[0014] In the method for preparing NK cells of the present invention, a major histocompatibility complex (MHC) or a killer immunoglobulin-like receptor (KIR) may not be the same between the hematopoietic precursor cells and a patient.
[0015] The present invention provides a pharmaceutical composition for use in cell therapy containing the NK cells prepared by the preparation method of the present invention. The pharmaceutical composition of the present invention may contain, in addition to the NK cells prepared by the preparation method of the present invention, an NK cell precursor, T cells, an NKT cells, and hematopoietic precursor cells in some cases. The present invention provides a method for preparing the pharmaceutical composition for use in cell therapy of the present invention.
[0016] The pharmaceutical composition of the present invention may be used for treating an infectious disease and/or a cancer in some cases.
[0017] The present invention provides cell therapy. The cell therapy of the present invention includes a step of expanding hematopoietic precursor cells under a single culturing condition; and a step of differentially inducing the cells obtained in the expanding step into NK cells. In the cell therapy, a medium used in the step of expanding hematopoietic precursor cells under a single culturing condition may be supplemented with IL-15, SCF, IL-7 and Flt3L in some cases. In the cell therapy, the medium used in the step of expanding hematopoietic precursor cells under a single culturing condition may be supplemented further with TPO in some cases. In the cell therapy, the step of differentially inducing the NK cells may include culturing the expanded hematopoietic precursor cells under a culturing condition containing IL-2 in some cases. In the cell therapy, the medium used in each of the steps may be supplemented with a human AB-type serum and/or a human serum albumin. In the cell therapy, the hematopoietic precursor cells may be at least one of hematopoietic precursor cells selected from the group consisting of hematopoietic precursor cells contained in an umbilical cord blood and/or an adult blood cell tissue, hematopoietic precursor cells differentiation induced from induced pluripotent stem cells, embryonic stem cells and/or adult stem cells, and hematopoietic precursor cells directly converted from differentiated cells. In the cell therapy, the step of transplanting the NK cells into a patient may be a step of transplanting the NK cells together with other cells such as T cells or NKT cells in some cases. The cell therapy of the present invention may be employed for treating and/or preventing an infectious disease and/or a cancer.
[0018] The term “NK cells” as used herein refers to CD3-negative/CD56-positive mononuclear cells, and have a cytotoxic activity against cells in which expression of MHC class I molecules is reduced or the expression is lost.
[0019] The term “hematopoietic precursor cells” as used herein includes any cells having differentiation potency into blood cells of any one of cell types. The hematopoietic precursor cells of the present invention include, but are not limited to, an umbilical cord blood, hematopoietic stem cells derived from an adult blood cell tissue such as a bone marrow, hematopoietic precursor cells differentiation induced from induced pluripotent stem cells, embryonic stem cells and/or adult stem cells, and hematopoietic precursor cells directly converted from differentiated cells of fibroblasts or the like. The hematopoietic precursor cells of the present invention are included in CD34-positive cells. The hematopoietic precursor cells of the present invention may be prepared, however, by a method using a marker other than CD34 as long as CD34-positive cells are substantially contained. The hematopoietic precursor cells of the present invention may be prepared by any procedures known to those skilled in the art. For example, in collecting mononuclear cells from an umbilical cord blood, specific gravity centrifugation may be employed. Besides, hematopoietic precursor cells present in an umbilical cord blood can be selectively collected from mononuclear cells derived from the umbilical cord blood by using immunomagnetic beads on which an antibody to a cell surface marker is immobilized. As the immunomagnetic beads, Dynabeads (registered trademark) manufactured by Dynal and available from Invitrogen, or CliniMACS (registered trademark) manufactured by Miltenyi Biotec may be used, but the immunomagnetic beads are not limited to these. On the immunomagnetic beads, an anti-CD34 antibody is preferably immobilized. However, immunomagnetic beads on which another specifically bonding partner such as an antibody to a cell surface marker different from CD34 is immobilized may be used as long as CD34-positive cells derived from the umbilical cord blood can be collected. Besides, the hematopoietic precursor cells can be isolated/identified by performing immunofluorescent staining with a specific antibody to a cell surface marker and by using a flow cytometer. In the expansion method of the present invention, mononuclear cells separated from an umbilical cord blood may be cryopreserved and thawed in accordance with a time of transplantation to a patient to be used for expanding NK cells in some cases. The cryopreservation and thaw of the cells may be performed any method known to those skilled in the art. For the cryopreservation of the cells, any of commercially available cell cryopreservation solutions is used in some cases.
[0020] If the hematopoietic precursor cells are differentiation induced from induced pluripotent stem cells, embryonic stem cells and/or adult stem cells, the hematopoietic precursor cells may be differentiation induced from undifferentiated pluripotent stem cells by employing a culturing condition not using feeder cells and a serum, such as one reported by Niwa, A. et al., (PLoS ONE 6(7): e22261 (2011)), in some cases. To be brief, human ES cells or human iPS cells are allowed to form colonies in a serum-free medium for retaining the cells in an undifferentiated state, the medium is replaced with a serum-free medium for differentiation induction supplemented with BMP4, and with this day set as day 0, the cells are cultured up to day 4. On day 4, the medium is replaced with a serum-free medium for differentiation induction supplemented with VEGF and SCF instead of BMP4, and the cells are cultured up to day 6. Thereafter, on day 6, the medium is replaced with a serum-free medium for differentiation induction supplemented with a stem cell factor (SCF), thrombopoietin (TPO), interleukin 3 (IL-3), FMS-like tyrosine kinase 3 ligand (F1t3L), a fusion protein of IL-6 receptor and IL-6 (FP6), and the like. On day 10 to 12, a cluster of hematopoietic cells starts to be observed in a margin of the colony, and starts to float in the medium several days later.
[0021] If the hematopoietic precursor cells are directly converted from differentiated cells such as fibroblasts, for example, a method reported by Szabo, E. et al. (Nature, 468: 521 (2010)) may be employed in some cases. To be brief, OCT4 protein is forcedly expressed in differentiated cells such as human fibroblasts, and cultured in a medium supplemented with a basic fibroblast growth factor (bFGF), insulin-like growth factor II (IGF-II), Flt-3L and SCF. After about 21 days, CD45-positive cells appear. The CD45-positive cells are transferred to another culture vessel, and are further cultured in a medium for hematopoietic differentiation supplemented with SCF, G-CSF, Flt-3L, IL-3, IL-6 and BMP-4. About a quarter of the CD45-positive cells obtained about 16 days after the cultivation in the medium for hematopoietic differentiation are positive also to CD34. Such cells are further differentiation induced into any of various blood cell types.
[0022] The term “umbilical cord blood” as used herein refers to both a fresh umbilical cord blood collected from an umbilical cord at the time of delivery and an umbilical cord blood in a frozen state available through an umbilical cord blood bank system in which an umbilical cord blood is cryopreserved after obtaining test data for histocompatibility.
[0023] The term “embryonic stem cells” as used herein refers to pluripotent stem cells derived from a mammal embryo before or after implantation. The term “adult stem cells” as used herein refers to stem cells that are derived from a somatic cell tissue obtained from any one of an embryo after the period of organogenesis or a fetus, a placenta thereof, and an individual of any age after delivery, and that have differentiation potency into cells of at least one or more cell types. The term “induced pluripotent stem cells” as used herein refers to pluripotent stem cells induced from non-pluripotent cells such as those described by Takahashi K. and Yamanaka S. (Cell, 126, 663 (2006)), and can be induced by any induction method.
[0024] In the NK cells obtained by the preparation method of the present invention, the pharmaceutical composition containing the NK cells and the cell therapy of the present invention, a solution for suspending or culturing living cells is, for example, a saline, a phosphate buffered saline (PBS), a medium, a serum or the like in general. The solution may contain a carrier pharmaceutically acceptable as a pharmaceutical or a quasi-pharmaceutical in some cases.
[0025] The NK cells obtained by the preparation method of the present invention, the pharmaceutical composition containing the NK cells and the cell therapy of the present invention can be applied to treatment and/or prevention of various diseases having sensitivity to NK cells. Examples of such diseases include, but are not limited to, cancers and tumors such as an oral cancer, a gallbladder cancer, a cholangiocarcinoma, a lung cancer, a liver cancer, a colorectal cancer, a kidney cancer, a bladder cancer and leukemia, and infectious diseases caused by viruses, bacteria and the like. The pharmaceutical composition containing the NK cells of the present invention may contain, in addition to the NK cells prepared by the method of the present invention, an NK cell precursor, T cells, NKT cells, hematopoietic precursor cells and other cells in some cases. The cell therapy of the present invention may be practiced singly or in combination with surgical treatment, chemotherapy, radiation therapy or the like in some cases. In the cell therapy of the present invention, the NK cells expanded by the method of the present invention may be transplanted into a patient together with T cells and NKT cells in some cases. In the cell therapy of the present invention, the NK cells may be transplanted by, for example, intravenous, intraarterial, subcutaneous or intraperitoneal administration in some cases.
[0026] In the method for preparing NK cells of the present invention, in the method for preparing the pharmaceutical composition of the present invention and in the cell therapy of the present invention, any of media such as, but not limited to, a KBM501 medium (Kohjin Bio Co., Ltd.), a CellGro SCGM medium (registered trademark, Cellgenix, Iwai Chemicals Company), a STEMLINE II (Sigma-Aldrich Co. LLC.), an X-VIVO15 medium (Lonza, Takara Bio Inc.), IMDM, MEM, DMEM and RPMI-1640 may be singly used as or blended in an appropriate ratio to be used as a medium for culturing cells in some cases. Besides, the media for culturing cells may be used with supplementation of at least one additional component selected from the group consisting of a serum, a serum albumin, an appropriate protein, a cytokine, an antibody, a compound and another component, which will be described below, in some cases.
[0027] The medium may be supplemented with an autologous serum of a subject, a human AB-type serum available from BioWhittaker Inc. or the like, or a donated human serum albumin available from Japanese Red Cross Society in some cases. The autologous serum and the human AB-type serum is supplemented preferably in a concentration of 1 to 10%, and the donated human serum albumin is supplemented preferably in a concentration of 1 to 10%. The subject may be a healthy person, or a patient having any of various diseases sensitive to NK cells.
[0028] The medium may be supplemented with an appropriate protein, a cytokine, an antibody, a compound or another component as long as the effect of expanding NK cells is not impaired. The cytokine may be interleukin 2 (IL-2), interleukin 3 (IL-3), interleukin 7 (IL-7), interleukin 12 (IL-12), interleukin 15 (IL-15), interleukin 21 (IL-21), stem cell factor (SCF), thrombopoietin (TPO) and/or FMS-like tyrosine kinase 3 ligand (F1t3L) in some cases. The IL-2, IL-3, IL-7, IL-12, IL-15, IL-21, SCF, TPO and Flt3L preferably have a human amino acid sequence, and are preferably produced by a recombinant DNA technology from the safety viewpoint. The IL-15 is used preferably in a concentration of 0.1 to 100 ng/mL, more preferably in a concentration of 20 to 30 ng/mL, and particularly preferably in a concentration of 25 ng/mL. The SCF is used preferably in a concentration of 2 to 100 ng/mL, more preferably in a concentration of 20 to 30 ng/mL, and particularly preferably in a concentration of 25 ng/mL. The IL-7 is used preferably in a concentration of 0.5 to 100 ng/mL, more preferably in a concentration of 20 to 30 ng/mL, and particularly preferably in a concentration of 25 ng/mL. The F1t3L is used preferably in a concentration of 1 to 100 ng/mL, more preferably in a concentration of 20 to 30 ng/mL, and particularly preferably in a concentration of 25 ng/mL. The TPO is used preferably in a concentration of 1 to 100 ng/mL, more preferably in a concentration of 20 to 30 ng/mL, and particularly preferably in a concentration of 25 ng/mL.
[0029] Herein, the concentration of the IL-2 may be shown in Japanese Reference Unit (JRU) and International Unit (IU). Since 1 IU corresponds to approximately 0.622 JRU, 1750 JRU/mL corresponds to approximately 2813 IU/mL. The IL-2 preferably has a human amino acid sequence and is preferably produced by a recombinant DNA technology from the safety viewpoint. The IL-2 is used preferably in a concentration of 100 to 2900 IU/mL, more preferably in a concentration of 100 to 2813 IU/mL, and particularly preferably 2813 IU/mL.
[0030] In the preparation method of the present invention and in the cell therapy of the present invention, in the step of expanding hematopoietic precursor cells, the cells are cultured in a medium supplemented with IL-15, SCF, IL-7 and Flt3L. The medium may be supplemented further with TPO in some cases. The medium may be replaced at any time after starting the cultivation as long as a desired number of NK cells can be obtained, and is preferably replaced every 3 to 5 days. In the expansion of the hematopoietic precursor cells, the cell growth rate is abruptly lowered in about 5 weeks. Therefore, the expansion of the hematopoietic precursor cells is conducted for about 5 weeks, namely, for 32, 33, 34, 35, 36, 37 or 38 days, after starting the cultivation. Thereafter, from the expanded hematopoietic precursor cells, NK cells are differentiation induced. In the step of differentially inducing NK cells, the cells are cultured in a medium supplemented with IL-2. The differentiation induction of NK cells is conducted for about 1 week, namely, for 5, 6, 7, 8 or 9 days. Here, cultivation conducted for n days under a given culturing condition refers to that the cultivation is conducted from a cultivation start date to n days after under the culturing condition, and means that transition to a next culturing condition or cell collection is performed n days after starting the cultivation.
[0031] In the present invention, the hematopoietic precursor cells may be frozen during the expansion or after completing the expansion, and thawed in accordance with a time of transplantation into a patient to be used for the transplantation into the patient in some cases. The cells may be frozen and thawed by any of methods known to those skilled in the art. For freezing the cells, any of commercially available cryopreservation solutions is used in some cases.
[0032] In the expansion method of the present invention, the culture vessel includes, but is not limited to, commercially available dishes, flasks, plates and multi-well plates. The culturing condition is not especially limited as long as the effect of expanding NK cells is not impaired, but a culturing condition of 37° C., 5% CO 2 and a saturated water vapor atmosphere is generally employed. Since the purpose of the present invention is to prepare a large amount of NK cells, it is advantageous that the time period of culturing the cells in the medium is longer because a larger amount of NK cells can be thus obtained. The culture period is not especially limited as long as the NK cells can be expanded to a desired number of cells.
[0033] The method and the production of the pharmaceutical composition of the present invention are practiced preferably under conditions complying with good manufacturing practices (GMP) for pharmaceuticals and quasi-pharmaceuticals.
[0034] The cytotoxic activity of the NK cells thus prepared is evaluated by a method known to those skilled in the art. In general, the cytotoxic activity is quantitatively determined by incubating the NK cells (effector cells) and target cells labeled with a radioactive substance, a fluorescent dye or the like, and then measuring a radiation dose or a fluorescence intensity. The target cells may be K562 cells, acute myelogenous leukemia cells, or chronic myelogenous leukemia cells in some cases, but are not limited to these. The properties of the expanded NK cells may be checked by employing RT-PCR, solid phase hybridization, ELISA, Western blotting, immune precipitation, immunonephelometry, FACS, flow cytometry or the like in some cases.
[0035] In the present invention, the collection and cryopreservation of an umbilical cord blood and/or adult blood cell tissue, the preparation of an autologous serum, the preparation of an umbilical cord blood and/or adult blood cell tissue, and mononuclear cells differentiation induced from pluripotent stem cells such as induced pluripotent stem cells, embryonic stem cells or adult stem cells, the preparation of hematopoietic precursor cells from the mononuclear cells, the measurement of the number of cells before and after the cultivation of the hematopoietic precursor cells, the measurement of a constituent ratio among NK cells, T cells and other cell types in the hematopoietic precursor cells before and after the cultivation, the calculation of the expansion factor of the NK cells, and the statistical analysis of a measurement error or significance may be practiced by any methods known to those skilled in the art.
[0036] All the literatures mentioned herein are incorporated herein by reference.
BRIEF DESCRIPTION OF DRAWINGS
[0037] FIG. 1 illustrates line graphs for comparing change with time of the expansion factor of umbilical cord blood-derived hematopoietic precursor cells among a first protocol (I) in which the cells are expanded for 1 week by using an expansion culture medium 1, expanded for 4 weeks by using an expansion culture medium 2, and then cultured for 1 week with the medium replaced with a differentiation induction medium 1, a second protocol (II) in which the cells are expanded for 5 weeks by using the expansion culture medium 2 alone and then cultured for 1 week with the medium replaced with the differentiation induction medium 1, and a third protocol (III) in which the cells are expanded for 5 weeks by using an expansion culture medium 3 alone and then cultured for 1 week with the medium replaced with the differentiation induction medium 1.
[0038] FIG. 2 illustrates bar graphs of ratios of CD3-negative and CD56-positive NK cells obtained by the first protocol (I), the second protocol (II) and the third protocol (III).
[0039] FIG. 3 illustrates bar graphs of cytotoxic activity, against K562 cells, of the NK cells obtained by the first protocol (I), the second protocol (II) and the third protocol (III).
[0040] FIG. 4 illustrates bar graphs of ratios, in the CD3-negative and CD56-positive NK cells, of cells positive to CD69, CD335 (NKp46), CD337 (NKp30), CD314 (NKG2D), granzyme B and perforin in the umbilical cord blood-derived hematopoietic precursor cells having been subjected to the expansion and differentiation induction in the respective protocols.
[0041] FIG. 5 illustrates bar graphs of cytotoxic activity, against K562 cells, of NK cells (KBM501) obtained by the second protocol (II) and the third protocol (III), and NK cells obtained when the differentiation induction media used in these protocols are replaced from KBM501 to a Stemline II medium supplemented with 1750 JRU/mL, namely, 2813 IU/mL, of IL-2 (Stemline+IL−2: 2813 IU/mL).
DESCRIPTION OF EMBODIMENTS
[0042] Examples of the present invention described below are intended to be merely illustrative, and do not limit the technical scope of the present invention. The technical scope of the present invention is defined merely by the appended claims. Modifications of the present invention, such as addition, deletion and replacement of a constituent feature of the present invention, can be conducted without departing from the spirit of the present invention.
EXAMPLE 1
[0043] This example was performed for proving that NK cells having high purity and high activity can be obtained from umbilical cord blood-derived hematopoietic precursor cells by an expansion method of the present invention.
1. Materials and Methods
[0044] Human Umbilical Cord Blood-derived Hematopoietic Precursor Cells
[0045] A sample of human umbilical cord blood-derived hematopoietic precursor cells was obtained from PromoCell (Takara Bio Inc., C-12921) or ZenBio Inc. (B-Bridge Co., Ltd., SER-CD34-F). The sample was CD34-positive precursor cells purified from mononuclear cells by using immunomagnetic beads CD34 (CD34 positive rate: 90% or more) and frozen. It is noted that a written consent was obtained from the mother in collecting the sample. Besides, it was confirmed that the results of HIV virus test and hepatitis B virus test were negative.
Media and Reagents
[0046] As a medium, STEMLINE II (Sigma-Aldrich Co. LLC., Catalog No. S0192, Lot No. SLBB3210) and/or a KBM501 medium (Kohjin Bio Co., Ltd., Catalog No. 16025015, Lot No. K1M120924, supplemented with 1750 JRU/mL, namely, 2813 IU/mL, of IL2 and 2000 mg/mL or less of a human serum albumin) was used, and was supplemented with a human AB-type serum (Kohjin Bio Co., Ltd., Catalog No. 12181301, Lot No. 12020165) at a final concentration of 10%. Proteins such as a cytokine used to add in experiments described below were all human recombinant proteins unless otherwise mentioned.
[0047] Expansion (1) of Hematopoietic Precursor Cells
[0048] The umbilical cord blood-derived CD34-positive cells were thawed in accordance with the specifications of the manufacturer, and then diluted with an expansion culture medium 1 to a concentration of 5×10 5 cells/mL, and seeded in a 6-well culture plate (140675, nunc, ThermoFisher Scientific). The medium was replaced on the 5th day of the cultivation. The expansion culture medium 1 was a STEMLINE II medium supplemented with 25 ng/mL of TPO, 25 ng/mL of SCF, 25 ng/mL of F1t3L, 250 pg/mL of G-CSF, 10 pg/mL of GM-CSF, 50 pg/mL of IL-6 and a 10% human AB-type serum.
Expansion (2) of Hematopoietic Precursor Cells
[0049] The umbilical cord blood-derived CD34-positive cells were cultured in the expansion culture medium 1 for 1 week, washed with PBS three times, diluted with an expansion culture medium 2 to 5×10 5 cells/mL, seeded in a 6-well culture plate (140675, nunc, ThermoFisher Scientific), and cultured for further 4 weeks. The medium was replaced every 4 days from the 3rd day of the cultivation. In replacing the medium, a cell suspension was collected and centrifuged at room temperature and 500 g for 5 minutes for removing the medium, and then, the resultant cells were diluted with a fresh expansion culture medium 2 to 5×10 5 cells/mL and seeded in a 6- well culture plate. The expansion culture medium 2 was a STEMLINE II medium supplemented with 25 ng/mL of IL-15, 25 ng/mL of SCF, 25 ng/mL of IL-7, 25 ng/mL of Flt3L, and a 10% human AB-type serum.
Expansion (3) of Hematopoietic Precursor Cells
[0050] The umbilical cord blood-derived CD34-positive cells were cultured for 5 weeks by using the expansion culture medium 2 alone. The medium was replaced every 4 days from the 3rd day of the cultivation.
Expansion (4) of Hematopoietic Precursor Cells
[0051] The umbilical cord blood-derived CD34-positive cells were cultured for 5 weeks by using an expansion culture medium 3 alone. The medium was replaced every 4 days from the 3rd day of the cultivation. The expansion culture medium 3 was a STEMLINE II medium supplemented with 25 ng/mL of IL-15, 25 ng/mL of SCF, 25 ng/mL of IL-7, 25 ng/mL of Flt3L, 25 ng/mL of TPO and a 10% human AB-type serum.
[0000] Differentiation Induction (1) into NK cells
[0052] The umbilical cord blood-derived CD34-positive cells were expanded by using any of the expansion culture media 1 to 3 for 35 days in total, and then, the medium was replaced with a differentiation induction medium 1 for inducing differentiation into NK cells for 7 days. The differentiation induction medium 1 was a KBM501 medium supplemented with a 10% human AB-type serum.
[0053] Differentiation Induction (2) into NK Cells The umbilical cord blood-derived CD34-positive cells were expanded by using the expansion culture medium 3 for 35 days in total, and then, the medium was replaced with a differentiation induction medium 2 for inducing differentiation into NK cells for 7 days. The differentiation induction medium 2 was a STEMLINE II medium supplemented with 1750 JRU/mL, namely, 2813 IU/mL, of IL-2 and a 10% human AB-type serum.
[0054] Analysis of Number of Cells and Cell Surface Marker The number of the hematopoietic precursor cells was determined by measuring the number of living cells by using a counting chamber. As cell surface markers of the cells, an anti-CD3 antibody (BioLegend Japan Inc., Catalog No. 317308), an anti-CD56 antibody (318321, BioLegend Japan Inc., Catalog No. 304607), an anti-CD69 antibody (BioLegend Japan Inc., Catalog No. 310905), an anti-CD335 (NKp46) antibody (BioLegend Japan Inc., Catalog No. 331907), an anti-CD337 (NKp30) antibody (BioLegend Japan Inc., Catalog No. 325207), an anti-CD314 (NKG2D) antibody (BioLegend Japan Inc., Catalog No. 320805), an anti-granzyme B antibody (BD Pharmingen, Catalog No. 560211, Japan Becton, Dickinson and Company) and an anti-perforin antibody (BioLegend Japan Inc., Catalog No. 308111) were used, and the analysis was performed by the flow cytometry.
[0055] Cytotoxic Activity of Expanded NK Cells The NK cells were expanded and differentiation induced in accordance with methods described in this example to be used as effector cells. K562 cells of chronic myelogenous leukemia cells were cultured by a method known to those skilled in the art to be used as target cells. The cytotoxic activity of the expanded NK cells and NK cells not expanded (hereinafter designated as the “non-expanded NK cells”) was quantitatively determined by a method known to those skilled in the art. To be brief, the target cells were labeled by cultivation performed for 10 minutes in an RPMI-1640 medium supplemented with 3-3′-dioctadecyloxacarbocyanine (Sigma-Aldrich Co. LLC., Catalog No. D4292) in a final concentration of 0.01 mM. The target cells were washed with PBS(-) and an RPMI medium three times after labeling. The effector cells and the target cells were seeded in a round bottom 96-well culture plate, and cocultured in an RPMI medium for 4 hours. A ratio between the effector cells and the target cells (an E:T ratio) was adjusted to 2:1. The cytotoxic activity (%) was quantitatively determined by the flow cytometry by using 7-amino-actinomycin D (Sigma-Aldrich Co. LLC., A9400).
[0056] 2. Results
Expansion of Umbilical Cord Blood-Derived Hematopoietic Precursor Cells
[0057] FIG. 1 illustrates line graphs for comparing change with time of the expansion factor of the umbilical cord blood-derived hematopoietic precursor cells among the first protocol (corresponding to a graph plotted with white rhombuses (⋄), I) in which the cells were expanded for 1 week by using the expansion culture medium 1, expanded for 4 weeks by using the expansion culture medium 2, and then cultured for 1 week with the medium replaced with the differentiation induction medium 1, the second protocol (corresponding to a graph plotted with white squares (□), II) in which the cells were expanded for 5 weeks by using the expansion culture medium 2 alone and then cultured for 1 week with the medium replaced with the differentiation induction medium 1, and the third protocol (corresponding to a graph plotted with black triangles (▾), III) in which the cells were expanded for 5 weeks by using the expansion culture medium 3 alone and then cultured for 1 week with the medium replaced with the differentiation induction medium 1. The abscissa indicates the number of days from the start of the cultivation of the hematopoietic precursor cells prepared from the umbilical cord blood. The ordinate indicates the expansion factor obtained on the assumption that the number of cells at the start of the cultivation was 1. As illustrated in FIG. 1 , the growth rate of the umbilical cord blood-derived hematopoietic precursor cells was largely lowered from about the 30th day of the cultivation. While the expansion factors of the cells obtained by the first and third protocols were both approximately 10,000, the expansion factor of the cells obtained by the second protocol was approximately 1,000, and thus the number of the cells was increased by merely 1/10 as compared with that obtained by the first and third protocols. Incidentally, even when the cells were cultured in the expansion culture medium up to day 42, the number of cells was not substantially changed as compared with that obtained on day 35 (not shown).
[0058] FIG. 2 illustrates bar graphs of ratios of CD3-negative and CD56-positive NK cells contained in the umbilical cord blood-derived hematopoietic precursor cells having been subjected to the expansion and differentiation induction by the first protocol (I), the second protocol (II) and the third protocol (III). As illustrated in FIG. 2, while the ratio of the NK cells was approximately 90% in the cells expanded and differentiation induced by the second protocol, the ratio of the NK cells was merely approximately 80% in the cells expanded and differentiation induced by the first and third protocols. As illustrated in FIG. 1 , however, the expansion factor of the cells obtained by the second protocol was as low as 1/10 of the expansion factor of the cells obtained by the first and third protocols. Therefore, it was proved that the cells obtained by the third protocol contain a larger number of NK cells.
[0059] FIG. 3 illustrates bar graphs of the cytotoxic activity, against the K562 cells, of the NK cells obtained by the first protocol (I), the second protocol (II) and the third protocol (III). The ordinate indicates a percentage of the target cells, K562 cells, lysed when the cells were mixed in the ratio between the effector cells and the target cells (E:T ratio) of 2:1 and cocultured for 4 hours. Here, the umbilical cord blood-derived hematopoietic precursor cells having been subjected to the expansion and the differentiation induction by the respective protocols were directly used as the effector cells without further purifying the NK cells. As illustrated in FIG. 3 , the cell lysis ratio of the NK cells obtained by the second protocol was approximately 100%, and the cytotoxic activity was extremely high, but as for the cytotoxic activity of the NK cells obtained by the third protocol, the cell lysis ratio was approximately 95%. As illustrated in FIG. 1, the expansion factor of the cells obtained by the second protocol was as low as 1/10 of the expansion factor of the cells obtained by the first and third protocols. Therefore, it was found that the cells obtained by the third protocol contain a large number of cells having a higher cytotoxic activity than the cells obtained by the second protocol. According to the report of Non Patent Literature 3, the cytotoxic activity targeting the K562 cells is merely approximately 40% under the same coculturing condition. Accordingly, it was proved that the NK cells obtained by the method of the present invention have much higher cytotoxic activity than umbilical cord blood-derived NK cells obtained by the conventional technique although the expansion factor is substantially equivalent.
[0060] FIG. 4 illustrates bar graphs of ratios, in the CD3-negative and CD56-positive NK cells, of cells positive to CD69, CD335 (NKp46), CD337 (NKp30), CD314 (NKG2D), granzyme B and perforin in the umbilical cord blood-derived hematopoietic precursor cells having been subjected to the expansion and the differentiation induction by the respective protocols. In all the NK cells obtained through the expansion and the differentiation induction performed by any of the protocols, CD69, CD335 and CD337 were expressed in substantially 100% of the cells. A ratio of cells expressing CD314 (NKG2D) and cells expressing granzyme B or perforin was not largely different among all the NK cells obtained through the expansion and the differentiation induction performed by any of the protocols.
[0061] FIG. 5 illustrates bar graphs of the cytotoxic activity, against K562 cells, of NK cells (KBM501) obtained by the second protocol (II) and the third protocol (III), and NK cells obtained when the differentiation induction media used in the respective protocols were replaced from the KBM501 to a Stemline II medium supplemented with 2813 IU/mL of IL-2 (Stemline +IL-2: 2813 IU/mL). When the differentiation induction medium was replaced from the KBM501 to the Stemline II medium supplemented with 2813 IU/mL of IL-2, the cytotoxic activity was lowered to 70%, but this activity was much higher than the cytotoxic activity reported in Non Patent Literature 3 (approximately 40%). Accordingly, it was proved that the effects of the present invention can be exhibited if a differentiation induction medium supplemented with IL-2 is used regardless of the composition of a basal medium. | The object of the present invention is to develop a technique in which NK cells having a high cytotoxic activity can be prepared with high purity from hematopoietic precursor cells without using a serum or feeder cells of an animal.
A method for expanding NK cells includes the steps of expanding hematopoietic precursor cells under a single culturing condition using a medium supplemented with IL-15, SCF, IL-7 and Flt3L, and differentially inducing the cells obtained in the expanding step into NK cells under a culturing condition using a medium supplemented with IL-2. A pharmaceutical composition contains the NK cells prepared by the method for expanding NK cells of the present invention. The pharmaceutical composition of the present invention is used for treating an infectious disease and/or a cancer. | 2 |
RELATED APPLICATION
This is a divisional application of application Ser. No. 10/654,545 filed Sep. 3, 2003 now U.S. Pat. No. 7,081,342 which is a continuation of application Ser. No. 09/981,282 filed Oct. 18, 2001, which issued as U.S. Pat. No. 6,641,819, which is a continuation-in-part of application Ser. No. 09/461,879 filed Dec. 15, 1999, which is now abandoned, which is a continuation-in-part of application Ser. No. 09/298,110 filed Apr. 22, 1999, which is now abandoned.
SEQUENCE DISCLOSURE
A Sequence Listing in the form of a computer readable ASCII file in connection with the present invention was filed in application Ser. No. 09/981,282. This earlier filed CRF is incorporated herein by reference and applicant requests that this previously filed CRF be used as the CRF for this application. A paper copy of this sequence is included herein and is identical to this previously-filed CRF.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is broadly concerned with attenuated avirulent atypical porcine reproductive and respiratory syndrome (PRRS) virus (PRRSV), and corresponding live virus vaccines for administration to swine in order to confer effective immunity in the swine against PRRSV. The invention also includes methods of immunizing swine against PRRSV, and a new, highly efficient method of passaging viruses to attenuation. Furthermore, the invention provides methods of detecting and differentiating between field strains and an attenuated strain of PRRSV.
2. Description of the Prior Art
PRRS emerged in the late 1980's as an important viral disease of swine. PRRSV causes severe reproductive failure in pregnant sows, manifested in the form of premature farrowings, increased numbers of stillborn, mummified and weak-born pigs, decreased farrowing rate, and delayed return to estrus. Additionally, the respiratory system of swine infected with PRRSV is adversely affected, which is evidenced by lesions that appear in the lungs of infected swine. To combat the problems associated with PRRSV infection, vaccines have been developed which conferred immunity to then extant PRRSV strains.
Epidemics of an unusually severe form of PRRS, referred to hereafter as “atypical PRRS”, were first recognized in North America in the latter part of 1996. They differed from epidemics of “typical PRRS” in that: 1) clinical signs were more prolonged as well as more severe; 2) the incidence of abortion was greater, especially during early and middle gestation; 3) there was a higher incidence of gilt and sow mortality; 4) PRRSV was less often isolated from aborted fetuses, stillborn pigs, and liveborn pigs—perhaps because abortions were more often the result of acute maternal illness rather than transplacental infection; 5) lung lesions of young affected pigs were more extensive; and 6) commercially available vaccines provided little or no protection. Collectively these observation indicated the emergence of more virulent and antigenically distinct strains of PRRSV and the need for a new generation of PRRS vaccines.
The most frequently used method for producing attenuated, live-virus vaccine is to serially passage the virus in a substrate (usually cell culture) other than the natural host (S) until it becomes sufficiently attenuated (i.e., reduced in virulence or diseases-producing ability) to be used as a vaccine. For the first passage, a cell culture is infected with the selected inoculum. After obtaining clear evidence of virus replication (e.g., virus-induced cytopathic effects [CPE] in the infected cells), an aliquot of the cell culture medium, or infected cells, or both, of the first passage are used to infect a second cell culture. The process is repeated until one or more critical mutations in the viral genome cause sufficient attenuation so that the virus can be safely used as a vaccine. The degree of attenuation is usually determined empirically by exposing the natural host (S) to progressively greater passage levels of the virus.
The above procedure is fundamentally sound and has been successfully used for the development of numerous vaccines for human and veterinary use. However, it is relatively inefficient because the logarithmic phase of virus replication, during which mutations are most likely to occur, is often completed long before evidence of virus replication becomes visibly obvious.
Therefore, there is a decided need in the art for a vaccine that confers effective immunity against PRRSV strains, including recently discovered atypical PRRSV strains. There is also a need in the art for a method of making such a vaccine. Finally, what is needed is a method of passaging a virus that attenuates the virus more efficiently than was heretofore thought possible with the resulting attenuated virus eliciting PRRSV specific antibodies in swine thereby conferring effective immunity against subsequent infection by PRRSV.
SUMMARY OF THE INVENTION
The present invention overcomes the problems outlined above, and provides attenuated, atypical PRRSV strains, and corresponding improved modified-live vaccines which confer effective immunity to newly discovered atypical PRRSV strains. “Effective immunity” refers to the ability of a vaccine to prevent swine PRRSV infections, including atypical PRRSV infections, which result in substantial clinical signs of the disease. That is to say, the immunized swine may or may not be serologically positive for PRRSV, but do not exhibit any substantial clinical symptoms. “Atypical PRRSV” refers to these new strains of PRRSV that are substantially more virulent than typical PRRSV strains.
In preferred forms, the vaccine of the invention includes live virus which has been attenuated in virulence. The resulting attenuated virus has been shown to be avirulent and to confer effective immunity. A particularly virulent strain of atypical PRRS (denominated JA-142) which caused especially severe symptoms of PRRS and represents the dominant strain of atypical PRRSV, was chosen for subsequent attenuation through passaging. The resultant attenuated virus has been deposited in the American Type Culture Collection (ATCC), Rockville, Md. on Feb. 2, 1999, and was accorded ATCC Accession No. VR-2638. This attenuated virus is a preferred Master Seed Virus (MSV) which has been subsequently passaged and developed as an effective PRRSV vaccine.
The name given the unattenuated virus, JA-142, arises from the restriction enzyme pattern. The 1 represents the inability of the enzyme MLUI to cleave the virus in open reading frame 5 (ORF 5). The 4 represents cleavage by Hinc II at base pair positions 118 and 249 of ORF 5 and short contiguous sequences. The 2 represents cleavage by Sac II at base pair position 54 of ORF 5 and short contiguous sequences.
Additionally, the present invention provides another way to differentiate between field strains of PRRSV and strain JA-142. The method is based upon differences in RNA cleavage by a restriction enzyme, NspI. Briefly, isolated PRRSV RNA is subjected to digestion by NspI. Digestion of the attenuated strain, JA-142, results in at least one additional fragment in comparison to field strains of PRRSV. In preferred methods, the RNA is isolated and RT-PCR is performed on the isolated RNA. This RNA is then subject to electrophoresis and a 1 Kd product is identified and purified for digestion by NspI. This digestion results in three fragments for JA-142 and either one or two fragments for PRRSV field strains.
Passaging of the virus to attenuation was accomplished using a novel method which resulted in increased efficiency. Specifically, the virus was kept in the logarithmic phase of replication throughout multiple cell culture passages in order to materially shorten the time to attenuation. This is achieved by ensuring that in each cell culture there is a substantial excess of initially uninfected cells relative to the number of virus present. Thus, by transferring only small numbers of virus from passage-to-passage, logarithmic replication is assured.
In practice, the process is normally initiated by inoculation of several separate cell cultures with progressively smaller viral aliquots (i.e., lesser numbers of virus in each culture.) For example, starting cultures could contain 200 μl, 20 μl and 2 μl viral aliquots. After an initial short incubation period (e.g., ˜24 hours), the same viral aliquots (in the example, 200 μl, 20 μl and 2 μl) from each cell culture are transferred to individual fresh (previously uninfected) cultures, while the starting cultures are monitored until cytopathic effect (CPE) is or is not observed. This process is continued in serial order for multiple passages, using the same viral aliquots in each case and preserving the cultures for CPE observation. If all of the serial culture passages exhibit CPE after a selected number of passages are complete, the larger viral aliquot series may be terminated (in the example 200 μl and 20 μl), whereupon another series of progressively smaller viral aliquots are employed (e.g., 2 μl, 0.2 μl and 0.02 μl) and the process is again repeated, again keeping the cell cultures after transfer for CPE observation.
At some point in this successively smaller viral aliquot inoculation process, CPE will not be observed in a given cell culture. When this occurs, the next higher viral aliquot level showing CPE is substituted for the passage in which CPE was not observed, whereupon subsequent passages will be inoculated using previously employed viral aliquots.
Inasmuch as a virus will tend to become more efficient at infecting cells and also replicate to a higher infectivity titer for cell cultures over time, (which is especially true with RNA viruses such as PRRSV), it will be seen that smaller and smaller viral aliquots are required to maintain infection during serial transfer. The use of the smallest aliquot that maintains infection helps to assure that viral replication remains in a logarithmic phase throughout the process.
The DNA sequence of the attenuated passaged virus from the 201st passage was then determined using conventional methods. The sequence of this attenuated virus was designated as MSV JA-142 Passage No. 201, the sequence of which is given as SEQ ID No. 1. The sequence of the virulent virus, JA-142, is given as SEQ ID No. 2.
As used herein, the following definitions will apply: “Sequence Identity” as it is known in the art refers to a relationship between two or more polypeptide sequences or two or more polynucleotide sequences, namely a reference sequence and a given sequence to be compared with the reference sequence. Sequence identity is determined by comparing the given sequence to the reference sequence after the sequences have been optimally aligned to produce the highest degree of sequence similarity, as determined by the match between strings of such sequences. Upon such alignment, sequence identity is ascertained on a position-by-position basis, e.g., the sequences are “identical” at a particular position if at that position, the nucleotides or amino acid residues are identical. The total number of such position identities is then divided by the total number of nucleotides or residues in the reference sequence to give % sequence identity. Sequence identity can be readily calculated by known methods, including but not limited to, those described in Computational Molecular Biology, Lesk, A. N., ed., Oxford University Press, New York (1988), Biocomputing: Informatics and Genome Projects, Smith, D. W., ed., Academic Press, New York (1993); Computer Analysis of Sequence Data, Part I, Griffin, A. M., and Griffin, H. G., eds., Humana Press, New Jersey (1994); Sequence Analysis in Molecular Biology, von Heinge, G., Academic Press (1987); Sequence Analysis Primer, Gribskov, M. and Devereux, J., eds., M. Stockton Press, New York (1991); and Carillo, H., and Lipman, D., SIAM J. Applied Math., 48: 1073 (1988), the teachings of which are incorporated herein by reference. Preferred methods to determine the sequence identity are designed to give the largest match between the sequences tested. Methods to determine sequence identity are codified in publicly available computer programs which determine sequence identity between given sequences. Examples of such programs include, but are not limited to, the GCG program package (Devereux, J., et al., Nucleic Acids Research, 12(1):387 (1984)), BLASTP, BLASTN and FASTA (Altschul, S. F. et al., J. Molec. Biol., 215:403-410 (1990). The BLASTX program is publicly available from NCBI and other sources (BLAST Manual, Altschul, S. et al., NCVI NLM NIH Bethesda, Md. 20894, Altschul, S. F. et al., J. Molec. Biol., 215:403-410 (1990), the teachings of which are incorporated herein by reference). These programs optimally align sequences using default gap weights in order to produce the highest level of sequence identity between the given and reference sequences. As an illustration, by a polynucleotide having a nucleotide sequence having at least, for example, 95% “sequence identity” to a reference nucleotide sequence, it is intended that the nucleotide sequence of the given polynucleotide is identical to the reference sequence except that the given polynucleotide sequence may include up to 5 point mutations per each 100 nucleotides of the reference nucleotide sequence. In other words, in a polynucleotide having a nucleotide sequence having at least 95% identity relative to the reference nucleotide sequence, up to 5% of the nucleotides in the reference sequence may be deleted or substituted with another nucleotide, or a number of nucleotides up to 5% of the total nucleotides in the reference sequence may be inserted into the reference sequence. These mutations of the reference sequence may occur at the 5′ or 3′ terminal positions of the reference nucleotide sequence or anywhere between those terminal positions, interspersed either individually among nucleotides in the reference sequence or in one or more contiguous groups within the reference sequence. Analogously, by a polypeptide having a given amino acid sequence having at least, for example, 95% sequence identity to a reference amino acid sequence, it is intended that the given amino acid sequence of the polypeptide is identical to the reference sequence except that the given polypeptide sequence may include up to 5 amino acid alterations per each 100 amino acids of the reference amino acid sequence. In other words, to obtain a given polypeptide sequence having at least 95% sequence identity with a reference amino acid sequence, up to 5% of the amino acid residues in the reference sequence may be deleted or substituted with another amino acid, or a number of amino acids up to 5% of the total number of amino acid residues in the reference sequence may be inserted into the reference sequence. These alterations of the reference sequence may occur at the amino or the carboxy terminal positions of the reference amino acid sequence or anywhere between those terminal positions, interspersed either individually among residues in the reference sequence or in the one or more contiguous groups within the reference sequence. Preferably, residue positions which are not identical differ by conservative amino acid substitutions. However, conservative substitutions are not included as a match when determining sequence identity.
Similarly, “sequence homology”, as used herein, also refers to a method of determining the relatedness of two sequences. To determine sequence homology, two or more sequences are optimally aligned as described above, and gaps are introduced if necessary. However, in contrast to “sequence identity”, conservative amino acid substitutions are counted as a match when determining sequence homology. In other words, to obtain a polypeptide or polynucleotide having 95% sequence homology with a reference sequence, 95% of the amino acid residues or nucleotides in the reference sequence must match or comprise a conservative substitution with another amino acid or nucleotide, or a number of amino acids or nucleotides up to 5% of the total amino acid residues or nucleotides, not including conservative substitutions, in the reference sequence may be inserted into the reference sequence.
A “conservative substitution” refers to the substitution of an amino acid residue or nucleotide with another amino acid residue or nucleotide having similar characteristics or properties including size, hydrophobicity, etc., such that the overall functionality does not change significantly.
Isolated” means altered “by the hand of man” from its natural state., i.e., if it occurs in nature, it has been changed or removed from its original environment, or both. For example, a polynucleotide or polypeptide naturally present in a living organism is not “isolated,” but the same polynucleotide or polypeptide separated from the coexisting materials of its natural state is “isolated”, as the term is employed herein.
Preferably, sequences sharing at least about 75%, more preferably at least about 85%, still more preferably at least about 90% and most preferably at least about 95% sequence homology with SEQ ID No. 1 are effective as conferring immunity upon animals vaccinated with attenuated viruses containing such homologous sequences. Alternatively, sequences sharing at least about 65%, more preferably at least about 75%, still more preferably at least about 85%, and most preferably at least about 95% sequence identity with SEQ ID No. 1 are also effective at conferring immunity upon animals vaccinated with attenuated viruses containing such identical sequences.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph illustrating the ratio of samples which tested positive for antibodies against PRRSV to the total number of samples over a 196 day testing period; and
FIG. 2 is a graph illustrating the ratio of samples which tested positive for antibodies against PRRSV to the total number of samples over a 38 day testing period after challenge.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The following examples set forth preferred embodiments of the present invention. It is to be understood, however, that these examples are provided by way of illustration and nothing therein should be taken as a limitation upon the overall scope of the invention.
Example 1
Materials and Methods
This example describes a passage method of attenuating viruses which maximizes attenuation efficiency by ensuring that the virus is preferably in a logarithmic phase of replication. Virus was passed (i.e. an aliquot of nutrient medium including the virus, unattached cells, and cell debris from a virus-infected cell culture was added to the nutrient medium of a noninfected culture) at daily intervals. Different amounts of virus were added at each interval by using multiple cultures. For example, at the beginning, 200 μl was transferred to one noninfected culture, 20 μl was added to a second noninfected culture, and 2 μl to a third noninfected culture. The goal was to have a sufficient amount of susceptible cells so that the replication cycles could continue until the next transfer. The procedure was deemed successful if the cells eventually showed CPE. However, because PRRSV-induced CPE do not appear until sometime after the logarithmic growth phase, passages were made before it was known whether or not they would be ultimately successful (“blind passages”). Passages that resulted in virus induced CPE were said to have resulted in a “take”. If a passage did not result in a take, the passage was restarted using the highest dilution from the last passage which did result in a take. As more and more passages were made, the virus became more adapted to replicate in the cell line and less able to produce disease symptoms in its original host. These changes occur through random mutations that occur during replication.
Using this method, the following procedures were used to passage an exemplary virus in accordance with the present invention, MSV, JA-142. This strain was passaged in MARC-145 cell cultures at daily intervals. Twenty-four-well plates were used for the process to minimize the amount of cells and nutrient medium required, and to simplify the multiple-aliquot passage technique. Cells and nutrient medium were added to each well and the cells were allowed to form, or nearly form (greater than about 70%), a confluent monolayer. The nutrient medium comprised approximately 90% Earle's balanced salt solution minimal essential medium (MEM), 10% fetal calf serum and 0.05 mgm/ml of gentamicin sulfate. The volume of nutrient medium used was approximately 1 ml. Usually, three wells of a column were used for each amount of virus that was transferred. An aliquot of nutrient medium from the previous passage was transferred to the first well in the column at 48 or 72 hours, after the cell cultures had been prepared, nutrient medium from the first well was transferred to the second well of the same column at 72 or 96 hours and the third well of the same column at 96 or 120 hours. Plates were usually set up twice a week so sometimes the fourth well of the column was used and sometimes it was not used. Passaging conditions were maintained at 37° C. in a moist atmosphere containing 5% CO 2 .
Different sized aliquots (having different amounts of virus) for each passage were tested to determine if the amount of virus was sufficient to induce CPE. For example, a separate series of aliquot transfers (passages) of 200 μl, 20 μl, and 2 μl, respectively, was used until the smaller aliquots consistently exhibited CPE with the goal being to transfer the smallest aliquot that produced CPE. When the smallest aliquot (e.g. 2 μl) of the group of aliquots being tested consistently resulted in CPE, smaller amounts were tested (e.g. 0.2 μl and 0.02 μl). When a certain dilution did not exhibit CPE, that series of cultures was restarted with the next lower amount which did result in CPE at that passage (i.e. if the 2 μl transfer was unsuccessful at producing CPE in the 25th passage but the 20 μl transfer in the 25th passage was successful, the 2 μl transfer was repeated using 20 μl with 2 μl transfers resuming for the 26th passage.)
Using this method, the smallest amount of virus necessary to transfer to obtain CPE was determined. Virus was passed successfully at daily intervals using the following amounts of virus-infected nutrient medium (which reflect the highest dilution [i.e., smallest aliquot] which resulted in CPE keeping in mind that other dilutions would also work):
Passage Number Amount Transferred 3-21 200 μl 22, 23 20 μl 24-41 200 μl 42-83 20/200 μl (alternating) 84-90 20 μl 91-112 2 μl 113 0.2 μl 114-116 2 μl 117 0.2 μl 118-120 2 μl 121 0.2 μl 122-124 2 μl 125-167 0.2 μl 168 0.02 μl 169-171 0.2 μl 172 0.02 μl 173-175 0.2 μl 176 0.02 μl 177-179 0.2 μl 180 0.02 μl 181-183 0.2 μl 184 0.02 μl 185-187 0.2 μl 188 0.02 μl 189-191 0.2 μl 192 0.02 μl 193-195 0.2 μl 196 0.02 μl 197 0.2 μl
Results and Discussion
The passaging of the virus using the above method resulted in an attenuated PRRSV, JA-142. As is apparent, the virus became more adapted to replicate in the cell culture and therefore required a smaller amount of virus-infected nutrient medium to be transferred as passaging continued. For transfers using a very small amount of virus-infected nutrient medium (e.g. 0.2 μl or 0.02 μl), a separate dilution was required. This dilution was accomplished by adding a small amount of virus-infected nutrient medium to a larger amount of nutrient medium. For example, to obtain a transfer of 0.2 μl, 2 μl of virus infected nutrient medium was added to 20 μl of nutrient medium and 2 μl of this dilution was added to the next culture in the series. Using this approach, the highest dilution which resulted in CPE was used and the time necessary for passaging the virus was minimized. Passaging at daily intervals ensured that the virus was always in a logarithmic phase of replication. Daily transferring also ensured that there was an adequate number of cells for virus replication.
Because the mutations (which are probably cumulative) that are likely to result in attenuation only occur during replication, there is no advantage to having substantially all cells infected and replication either proceeding at a slower rate or stopping before the next transfer. Based on previous studies of PRRSV, it was known that the replication cycle is about 8 hours, therefore, transferring a minimal amount of virus from virus-infected nutrient medium to uninfected nutrient medium at daily intervals results in the virus always having plenty of cells within which to replicate.
As can be readily appreciated, passaging using this method results in a savings of time that was heretofore thought impossible (i.e. each passage required less time). This is especially important when a high number of passages are required for adequate virus attenuation. If each passage, using old methods, was performed at a 3 day interval, a procedure requiring 200 passages would take 400 fewer days using the method of the present invention.
Example 2
Materials and Methods
This example determined if passage 200 of PRRS Virus, JA-142, would revert in virulence when passed in the host animal six times. This study consisted of six groups. Five pigs from group 1 (principle group) were inoculated intra-nasally with PRRS MSV, JA-142 passage 200, while three pigs from group 1A, (control group) were inoculated intra-nasally with sterile diluent. The animals were provided commercial feed and water ad libitum throughout the study. Pigs of both treatment groups were monitored daily for clinical signs (appearance, respiratory, feces, etc.). After six days, the animals were weighed, bled and sacrificed. After scoring the lungs for lesions, lung lavages were collected from each animal. The lung lavages were frozen and thawed one time, and a pool was prepared using 2.0 ml of serum and 2.0 ml of lung lavage from each animal within a group to prepare Backpassage 1 and 1A, respectively. This pool was used to challenge (intra-nasally) the animals in group 2 and group 2A, respectively. This process was repeated for groups 3 and 3A through 6 and 6A. Animals in each group were housed in separate but identical conditions.
Following inoculation, blood samples were collected and body temperatures were monitored. Rectal temperatures were measured for each animal periodically from −1 DPE (days post exposure) to 6 DPE and averaged together with other animal temperatures from the same group. The health status of each animal was monitored daily for the duration of the study. Results were compiled and scored on a daily observation form. The scoring parameters are as follows:
1. Appearance
normal=0; depressed=1; excited=2; comatose/death=30.
2. Respiration
normal=0; sneeze=1; cough=1; rapid/short=2; labored=3.
3. Feces
normal=0; dry=1; loose=2; fluid=3.
4. Eyes
normal=0; watery=1; matted=2; sunken=3.
5. Nostrils
normal=0; watery discharge=1; red/inflamed=2; crusted ulcers=3.
6. Mouth
normal=0; slobbers=2; ulcer=3.
7. Activity
NA
8. Appetite
normal=0; decreased=1; anorexic (none)=3.
9. Other
Animals were also weighed prior to inoculation and at necropsy. Average weight gains for each group were calculated for comparison. PRRS Enzyme Linked Immuno-Absorbent Assays (ELISA) and serum neutralization (SN) assays were performed following the exposures of the animals with test and control articles. Attempts to isolate PRRSV from serum samples were performed on MA-104 cells. Prior to and following vaccination, total white blood cell counts were determined using COULTER COUNTER MODEL Z1, Coulter Corp., Miami, Fla. At necropsy, the lungs of each animal were scored. Lung scoring was done by separating the lung into 7 sections and determining the percentage of lung involvement (the percentage of the lung area affected as shown by lesions or redness for each section and multiplying by the approximate area of the whole lung) that percentage of total lung area that the section encompasses. Parameters for lung scoring are as follows:
Left Apical Lobe % of involvement × 0.10 = Left Cardiac Lobe % of involvement × 0.10 = Left Diaphragmatic Lobe % of involvement × 0.25 = Right Apical Lobe % of involvement × 0.10 = Right Cardiac Lobe % of involvement × 0.10 = Right Diaphragmatic Lobe % of involvement × 0.25 = Intermediate Lobe of Right Lung % of involvement × 0.10 = Total (Sum of all values in the far right column) =
Results and Discussion
Each group of pigs was monitored for six days following vaccination. Clinical scores were low in all groups. Clinical score results are given in Table 1.
TABLE 1
Daily Clinical Scores
Treatment
Day − 1
Day 0
Day1
Day 2
Day 3
Day 4
Day 5
Day 6
Average
Group 1
Pig #
JA-142 psg 200
545
0
0
2
0
0
0
0
0
0.25
551
0
0
0
0
0
0
0
0
0
561
0
0
0
0
0
0
0
0
0
565
0
0
0
0
0
0
0
0
0
806
0
0
0
0
0
0
0
0
0
Average
0
0
0.4
0
0
0
0
0
0.05
Saline
550
0
0
0
0
0
0
0
0
0
568
0
0
0
0
0
0
0
0
0
801
0
0
0
0
0
0
0
0
0
Average
0
0
0
0
0
0
0
0
0
Group 2
Pig #
Backpassage 1
546
0
0
0
0
0
0
0
0
0
553
0
0
0
0
0
0
0
0
0
562
0
0
0
0
0
1
0
0
0.125
572
0
0
0
0
0
0
0
0
0
573
0
0
0
0
2
0
0
0
0.25
Average
0
0
0
0
0.4
0.2
0
0
0.075
Backpassage 1
556
0
0
0
0
0
0
0
0
0
566
0
0
0
0
0
0
0
0
0
802
0
0
0
0
0
0
0
0
0
Average
0
0
0
0
0
0
0
0
0
Group 3
Pig #
Backpassage 2
548
0
0
0
0
0
0
0
0
0
567
0
0
0
0
0
0
0
0
0
569
0
0
0
0
1
1
0
0
0.25
574
0
0
0
0
0
0
0
0
0
804
0
0
0
0
0
0
0
0
0
Average
0
0
0
0
0.2
0.2
0
0
0.05
Backpassage 2A
547
0
0
0
0
0
0
0
0
0
5564
0
0
0
0
0
0
0
0
0
805
0
0
0
0
0
0
0
0
0
Average
0
0
0
0
0
0
0
0
0
Group 4
Pig #
Backpassage 3
549
0
0
0
0
0
0
0
0
0
554
0
0
0
0
0
0
0
0
0
563
0
0
0
0
0
0
0
0
0
570
0
0
0
0
0
0
0
0
0
803
0
0
0
0
0
0
0
0
0
Average
0
0
0
0
0
0
0
0
0
Backpassage 3A
560
0
0
0
0
0
0
0
0
0
571
0
0
0
0
0
0
0
0
0
575
0
0
0
0
0
0
0
0
0
Average
0
0
0
0
0
0
0
0
0
Group 5
Pig #
Backpassage 4
1
0
2
0
0
2
0
2
2
1
2
0
0
0
0
0
0
0
0
0
3
2
0
2
2
2
2
2
2
1.75
4
0
0
0
0
0
0
0
0
0
5
0
0
0
0
0
0
0
0
0
Average
0.4
0.4
0.4
0.4
0.8
0.4
0.8
0.8
0.55
Backpassage 4A
6
0
0
0
0
0
0
0
0
0
7
0
0
2
2
2
2
2
2
1.5
8
0
0
0
0
0
0
0
0
0
Average
0
0.08
0.48
0.48
0.56
0.48
0.56
0.56
0.4
Group 6
Pig #
Backpassage 5
10
0
0
0
0
2
0
0
2
0.5
12
0
0
0
2
2
0
0
2
0.75
14
0
0
0
0
0
0
0
0
0
15
2
2
2
0
0
0
0
2
1
16
2
2
2
0
0
1
1
2
1.25
Average
0.8
0.8
0.8
0.4
0.8
0.2
0.2
1.6
0.7
Backpassage 5A
9
0
0
0
0
0
0
0
0
0
11
2
2
0
0
0
0
0
0
0.5
13
0
0
0
0
0
0
0
0
0
Average
0.666667
0.56
0.16
0.08
0.16
0.04
0.04
0.32
0.253333
There were no significant differences between groups for rectal temperatures or daily weight gains. All lung scores were negative.
Serologically, ELISA S/P ratios and SN titers were negative throughout each group's trial period. Virus isolation was attempted on all serum samples and lung lavages. By day 6, 60-100% of the serum samples from the groups given JA-142, passage 200, and subsequent back passes were positive. The groups given saline were negative. In the first three passes, virus was recovered in the lung lavages from only 20-40% of the pigs, but by the last three passes, the virus was recovered from 50-80% of the pigs.
Based on this data, JA-142 passage 200 did not revert to virulence when passed through pigs six times.
Example 3
Materials and Methods
This example demonstrated that the level of attenuation of safety of MSV, JA-142, passage 200 did not change significantly during six backpassages in the host animal. Evaluation of level of attenuation or safety was performed using the pregnant sow model and monitoring the effect on reproductive performance. This model is the most sensitive test system and does not rely upon subjective factors for virulence testing. This example consisted of four groups (A, B, C & D) having seven sows per group. Group A was inoculated intra-nasally with PRRS MSV, JA-142 passage 200. Group B was inoculated intra-nasally with JA-142, passage 200, Backpassage 6. Group C was inoculated intra-nasally with sterile diluent, to act as normal controls. Group D was inoculated intra-nasally with PRRSV JA-142, passage 4. The test articles (challenge with JA-142, passage 4) were given at about 93 days gestation. Body temperatures of the sows were monitored for the first seven days following vaccination. Blood samples were collected from the sows once a week and at time of farrowing. Blood samples were collected and weights were recorded from piglets at birth, 7, and 14 days of age. The health status of each animal was monitored daily for the duration of the study up to and following farrowing for 14 days. The farrowing performance was evaluated by observing the health status of the piglets born.
PRRS ELISA assays were performed following the exposures of the sows with the test article. PRRS ELISA assays were also performed on the piglet sera weekly following farrowing. Following exposure to the test article, attempts to isolate PRRSV from serum samples were performed on MA-104 cells. Rectal temperatures were measured periodically from 0 days post vaccination (DPV) to 7 DPV and the average temperature of each group was determined. Prior to and after inoculation, total white blood cell counts were determined as in Example 1. Clinical observations of the sows, as in Example 2, were made from −1 DPV through farrowing. Clinical observations of the piglets were made from farrowing until 14 days of age. Finally, at necropsy, the lungs of each piglet were scored for percent lung involvement.
Results
The ELISA results indicate that the animals used in this study were naive to PRRSV. Those animals that received virus inocula, groups A, B, and D, sero-converted at 14 days post treatment. Three sows of group B remained negative at 14 days post treatment. At the time of farrowing, the negative sows of group B tested positive for antibody to PRRSV.
The pigs' ELISA results indicated that the majority of the piglets born to sows of group A and group B were sampled after they had nursed. Those pigs that were negative at zero days post farrowing (0 DPF) tested positive at 7 DPF. All pigs born to sows of group C tested sero-negative throughout the study. Only a few pigs were tested from group D, since the majority were either stillborn or mummies. Half of those pigs that were tested were sero-positive. This indicated that the sero-negative pigs were sampled prior to nursing or they were not capable of nursing. All piglets born to sows of group D died before 7 DPF. Isolations of PRRSV from the sows of groups A and B were sporadic. Although the results of the ELISA test indicated that these sows were successfully inoculated with the viral test articles, many remained negative for virus isolation from serum.
The majority of pigs born to sows from groups A and B tested positive for virus isolation during the performance of the study. The litter born to one sow of group A never tested positive and the litter born to one sow of group B had only two of eight piglets test positive for virus isolation. No virus was recovered from the piglets born to sows from group C. Virus was recovered from the majority (71%) of piglets born from sows of group D.
Post treatment rectal temperatures were unremarkable. The groups that were treated with either MSV, backpassage 6 or sterile diluent experienced no measurements exceeding 101.7° F. Group D, treated with JA-142, passage 4, had four (out of seven) sows that experienced temperatures that exceeded 102° F. with one sow reaching 103.4° F. for one of the days. The weight gain performance of the piglets born to sows of groups A (treated with MSV) and B (treated with MSV, backpassage 6) was greater than that of the pigs born to the control sows of group C. The average weight gain for the 14 day observation period was 7.9 lbs. For group A, it was 7.7 lbs; for group B and group C it was 6.9 lbs. The difference in the weight gain was not related to the size of the litter remaining at 14 days. The average litter sizes at 14 days post farrowing (DPF) were 9 for group A, 7 for group B, and 10 for group C. No pig born to the sows of group D survived beyond 3 DPF.
The white blood cell (WBC) counts for the sows of groups A, B, and C remained relatively constant. The average percentages of the pre-challenge values were equal to or greater than 92% for the duration of the observation period. Three sows of group D experienced WBC counts that were lower than the expected normal range (7-20×10 6 /ml).
The post inoculation clinical scores were unremarkable for the sows of groups A and B. Several sows of group C were observed to experience clinical signs over a period of several days. The majority of the clinical symptoms observed were in the category of decreased appetite, respiratory symptoms, and depression. One sow of group C died on trial day 31 of chronic bacterial pneumonia. Six of the seven sows of group D were observed to have clinical signs, primarily of varying degrees in severity, of lost appetite, ranging from decreased to anorexic. Results of the clinical scoring for the sows are given in Table 2.
TABLE 2
Sow Clinical Scores
Treatment
Sow#
−3
−2
−1
0
1
2
3
4
5
6
7
8
9
10
11
12
Group A
98
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
JA-142 MSV
133
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Passage 200
147
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
178
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
215
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
233
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
243
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Group A
98
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
JA-142 MSV
133
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Passage 200
147
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
178
0
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
215
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
233
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
243
0
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0.6
0
0
0
0
0
0
0
0
0
0
0
0
0
0
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
Group A
98
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
JA-142 MSV
133
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Passage 200
147
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
178
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
215
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
233
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
243
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Treatment
Sow#
−3
−2
−1
0
1
2
3
4
5
6
7
8
9
10
11
12
Group B
49
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Backpassage6
100
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
135
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
149
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
209
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
212
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
226
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0
0
0
0
0
0
0
0
0
0.1
0.1
0.1
0.1
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Group B
49
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Backpassage6
100
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
135
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
149
0
0
0
0
0
0
0
1
1
0
0
0
0
0
0
0
209
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
212
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
226
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0
0
0
0
0.1
0.1
0
0
0
0
0
0
0
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
Group B
49
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Backpassage6
100
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
135
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
149
0
0
0
0
0
0
0
0
0
0
2
2
2
2
2
2
209
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
212
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
226
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0
0
0
0
0
0
0
0.3
0.3
0.3
0.3
0.3
0.3
Treatment
Sow#
−3
−2
−1
0
1
2
3
4
5
6
7
8
9
10
11
12
Group C
58
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Sterile
113
0
0
0
0
0
0
0
0
0
0
1
3
3
5
3
3
Diluent
117
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
144
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
156
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
166
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0
0
0
0
0
0
0
0.2
0.5
0.5
0.8
0.7
0.7
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Group C
58
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Sterile
113
3
3
3
3
3
3
4
4
4
4
6
6
2
4
2
2
Diluent
117
0
0
0
0
0
0
1
5
5
5
5
5
2
4
1
1
144
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
156
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
166
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0.8
0.5
0.5
0.5
0.5
0.5
0.8
1.5
1.5
1.5
1.8
1.8
0.7
1.3
0.5
0.5
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
Group C
58
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Sterile
113
2
2
30
Diluent
117
2
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
144
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
156
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
166
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0.7
0.7
6
0
0
0
0
0
0
0
0.2
0.2
0.2
0.2
0.2
0.2
Treatment
Sow#
−3
−2
−1
0
1
2
3
4
5
6
7
8
9
10
11
12
Group D
2
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
JA-142
106
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
Pass 4
159
0
0
0
0
0
0
0
0
0
3
1
1
1
1
1
1
190
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
206
0
0
0
0
0
0
0
0
0
0
1
1
0
0
0
0
232
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
234
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
Avg.
0
0
0
0
0
0
0
0
0
0.6
0.6
0.6
0.6
0.7
0.7
0.7
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Group D
2
1
1
3
3
1
0
0
0
0
0
0
0
0
0
0
0
JA-142
106
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Pass 4
159
1
1
1
1
3
4
2
3
3
3
2
0
0
2
0
0
190
1
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
206
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
232
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
234
0
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0.4
0.3
0.6
0.6
0.6
0.6
0.3
0.4
0.4
0.4
0.3
0
0
0.3
0
0
29
30
31
32
33
34
35
36
37
38
Group D
2
0
0
0
1
1
1
3
3
1
1
JA-142
106
0
0
0
0
0
0
0
0
0
0
Pass 4
159
0
0
0
0
0
0
0
0
0
0
190
0
0
0
0
0
0
0
0
0
0
206
0
0
0
0
0
0
0
0
0
0
232
0
0
0
0
0
0
0
0
0
0
234
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0.1
0.1
0.1
0.4
0.4
0.1
0.1
Clinical observations of the piglets fell into two major categories, death and reduced appetite. There were no significant differences between groups A, B and C in the area of average deaths per litter (DPL). Group A had an average of 1.3 DPL, group B had an average of 2.4 DPL, group C had an average of 2.0 DPL, and no pigs from group D survived beyond three days post farrowing. Clinical scores for the piglets are given in Table 3.
TABLE 3
Treatment
Sow#
Pig#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Group A
98
813
0
0
1
30
JA-142
814
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Pass 200
815
0
0
0
0
0
0
0
0
0
0
0
0
0
0
816
0
0
0
0
0
0
0
0
0
0
0
0
0
0
817
1
0
1
0
0
0
0
0
0
0
0
0
0
0
818
0
0
0
0
0
0
0
0
0
0
0
0
0
0
819
0
0
0
0
0
0
0
0
0
0
0
0
0
0
820
0
0
0
0
0
0
0
0
0
0
0
0
0
0
821
1
0
0
0
0
0
0
0
0
0
0
0
0
0
822
1
30
Avg.
0.3
3
0.2
3.3
0
0
0
0
0
0
0
0
0
0
133
720
30
721
0
1
0
0
0
0
0
0
0
0
0
0
0
0
722
0
0
0
1
0
0
0
0
0
0
0
0
0
0
723
0
0
0
0
0
0
0
0
0
0
0
0
0
0
724
0
1
0
0
0
1
0
0
0
0
0
0
0
0
725
0
0
0
0
0
0
0
0
0
0
0
0
0
0
798
0
0
0
0
0
0
0
0
0
0
0
0
0
0
799
30
800
0
0
0
0
0
0
0
0
0
0
0
0
0
0
807
0
0
0
0
0
0
0
0
0
0
0
1
0
0
809
0
0
0
0
0
0
0
0
0
0
0
0
0
0
810
0
0
0
0
0
0
0
0
0
0
0
0
0
0
812
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
4.6
0.2
0
0.1
0
0.1
0
0
0
0
0
0.1
0
0
147
823
0
0
0
0
0
0
0
0
0
0
0
0
0
0
824
0
0
0
0
0
0
0
3
1
1
1
1
1
1
825
0
0
0
0
0
0
0
0
0
0
0
0
0
0
845
0
0
0
0
0
0
0
0
0
0
0
0
0
0
846
0
0
0
0
0
0
0
0
0
0
0
0
0
0
847
0
0
0
0
0
0
0
0
0
0
0
0
0
0
848
0
0
0
0
0
0
1
0
0
0
0
0
0
0
849
0
0
0
0
0
0
0
0
0
0
0
0
0
2
850
30
976
0
0
0
0
0
0
0
0
0
0
0
0
0
0
977
0
0
0
0
1
1
3
30
978
30
Avg.
5
0
0
0
0.1
0.1
0.4
3.3
0.1
0.1
0.1
0.1
0.1
0.3
178
486
30
487
0
0
0
0
0
0
0
0
0
0
0
1
0
0
488
0
0
0
0
0
0
0
0
0
0
0
0
0
0
489
0
0
0
0
0
0
0
0
0
0
0
0
0
0
490
0
0
0
0
0
0
0
0
0
0
0
0
0
0
491
0
0
0
0
0
0
0
0
0
0
0
0
0
0
492
0
0
0
0
0
0
0
0
0
0
0
0
0
0
493
0
0
0
0
0
0
0
0
0
0
0
0
0
0
494
0
1
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
3.3
0.1
0
0
0
0
0
0
0
0
0
0.1
0
0
Group A
215
495
0
0
0
0
0
0
0
0
0
0
0
0
0
0
JA-142
496
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Pass 200
497
0
0
0
0
0
0
0
0
0
0
0
0
0
0
498
0
0
0
0
0
0
0
0
0
0
0
0
0
0
499
0
0
0
0
0
0
0
0
0
0
0
0
0
0
500
0
0
0
0
0
0
0
0
0
0
0
0
0
0
808
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0
0
0
0
0
0
0
0
0
0
0
233
476
0
0
0
0
0
0
0
0
0
0
0
0
0
0
477
0
0
0
0
0
0
0
0
0
0
0
0
0
0
478
0
0
0
0
0
0
0
0
0
0
0
0
0
0
478
0
0
0
0
0
0
0
0
0
0
0
0
0
0
480
0
0
0
0
0
0
0
0
0
0
0
0
0
0
481
0
0
0
0
0
0
0
0
0
0
0
0
0
0
482
0
0
0
0
0
0
0
0
0
0
0
0
0
0
483
0
0
0
0
0
0
0
0
0
0
0
0
0
0
484
0
0
0
0
0
0
0
0
0
0
0
0
0
0
485
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0
0
0
0
0
0
0
0
0
0
0
243
707
0
0
0
0
0
0
0
0
0
0
0
0
0
0
708
0
0
0
0
0
0
0
0
0
0
0
0
0
0
709
0
0
0
0
0
0
0
0
0
0
0
0
0
0
710
0
0
0
0
0
0
0
0
0
0
0
0
0
0
711
0
0
0
0
0
0
0
0
0
0
0
0
0
0
712
0
0
0
0
0
0
0
0
0
0
0
0
0
0
713
0
0
0
0
0
0
0
0
0
1
30
714
0
0
0
0
0
0
0
0
0
0
0
0
0
0
715
0
0
0
0
0
0
0
0
0
0
0
0
0
0
716
0
0
0
0
0
0
0
0
0
0
0
0
0
0
717
0
0
0
0
0
0
0
0
0
0
0
1
0
0
718
0
0
0
0
0
0
0
0
0
0
0
1
0
0
719
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0
0
0
0
0
0
0.1
2.3
0.2
0
0
Group B
Backpassage 6
49
430
0
0
0
0
0
0
0
0
0
0
0
0
0
0
431
0
0
0
0
0
0
0
0
0
0
0
0
0
0
432
0
0
0
0
0
0
0
0
0
0
0
0
0
0
433
0
0
0
0
0
0
0
0
0
0
0
0
0
0
434
0
0
0
0
0
0
0
0
0
0
0
0
0
0
435
0
0
0
0
0
0
0
0
0
0
0
0
0
0
436
0
0
0
0
0
0
0
0
0
0
0
0
0
0
437
0
0
0
0
0
0
0
0
0
0
0
0
0
0
438
30
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
3.3
0
0
0
0
0
0
0
0
0
0
0
0
0
100
459
0
0
0
0
0
0
0
0
0
0
0
0
0
0
460
0
0
0
0
0
0
0
0
0
0
0
0
0
0
461
0
0
0
0
0
0
1
1
1
0
0
0
0
0
462
0
0
0
0
1
1
1
1
1
1
1
1
1
1
463
0
0
0
0
0
0
0
0
0
0
0
0
0
0
464
0
0
1
1
1
1
30
465
0
30
Avg.
0
4.3
0.2
0.2
0.3
0.3
5.3
0.4
0.4
0.2
0.2
0.2
0.2
0.2
135
439
0
0
0
0
0
0
0
30
440
0
0
0
0
0
0
0
0
0
0
0
0
0
0
441
0
0
0
0
0
0
0
0
0
0
0
0
0
0
442
0
0
0
1
1
1
1
1
1
1
3
3
3
30
443
0
0
0
0
0
0
0
0
0
0
0
0
0
0
444
0
0
0
0
0
0
1
1
0
0
0
0
0
0
445
0
0
0
0
0
0
0
0
0
0
0
0
0
0
446
0
0
0
0
0
0
0
0
0
0
0
0
0
0
447
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0.1
0.1
0.1
0.2
3.6
0.1
0.1
0.4
0.4
0.4
3.8
149
231
0
0
0
0
0
0
0
0
0
0
0
0
0
0
232
0
0
0
0
0
0
0
0
0
0
0
0
0
0
233
0
0
0
0
0
0
30
234
0
0
0
0
0
0
3
1
1
3
1
1
1
1
235
0
0
0
0
0
0
3
2
3
3
0
0
0
0
236
0
0
0
0
0
0
0
0
0
0
0
0
0
0
237
0
0
0
0
0
0
1
1
1
1
1
1
1
1
238
0
0
0
0
0
2
0
0
0
0
0
0
0
0
239
0
0
30
240
30
241
3
30
242
0
0
0
0
0
2
3
3
30
Avg.
2.8
2.7
3
0
0
0.4
4.4
0.9
4.4
1
0.3
0.3
0.3
0.3
Group B
209
448
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Backpassage 6
449
0
0
0
0
0
0
0
0
0
0
0
0
0
0
450
0
0
0
0
0
0
0
0
0
0
0
0
0
0
451
0
0
0
0
0
0
0
0
1
1
1
1
1
1
452
0
0
0
0
0
0
0
0
0
0
0
0
0
0
453
0
0
0
0
0
0
0
0
0
0
0
0
0
0
454
0
0
0
0
0
0
0
0
1
1
1
1
1
1
455
0
0
0
0
0
0
0
0
0
1
1
1
1
1
456
30
457
0
0
0
0
0
0
0
0
2
1
1
1
1
1
458
30
Avg.
5.5
0
0
0
0
0
0
0
0.4
0.4
0.4
0.4
0.4
0.4
212
243
0
0
0
0
0
0
0
0
0
0
0
0
0
0
244
0
0
0
0
0
0
0
0
0
0
0
0
0
0
245
0
0
0
0
3
1
30
246
0
0
0
0
0
0
0
0
0
0
0
0
0
0
247
0
0
0
0
0
2
2
0
0
0
0
0
0
0
248
0
0
0
0
2
0
0
0
0
0
0
0
0
0
249
0
0
0
0
0
0
2
2
0
0
2
0
0
0
250
0
0
0
3
30
426
0
0
0
0
0
0
0
0
0
0
0
0
0
0
427
0
0
0
1
3
1
1
30
428
0
0
0
1
3
3
30
429
0
0
0
0
2
3
3
3
3
3
3
1
30
Avg.
0
0
0
0.4
3.6
0.9
6.2
3.9
0.4
0.4
0.6
0.1
3.8
0
226
Not
Preg.
Group C
Sterile
58
24
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Diluent
25
0
0
0
0
0
0
0
0
0
0
0
0
0
0
46
0
0
0
0
0
0
0
0
0
0
0
0
0
0
47
0
0
0
0
0
0
0
0
0
0
0
0
0
0
48
0
0
0
0
0
0
0
0
0
0
0
0
0
0
49
0
0
0
0
0
0
0
0
0
0
0
0
0
0
50
0
0
0
0
0
0
0
0
0
0
0
0
0
0
51
0
0
0
2
2
1
1
1
30
Avg.
0
0
0
0.3
0.3
0.1
0.1
0.1
3.8
0
0
0
0
0
113
17
30
18
30
19
30
20
30
21
0
30
22
30
23
30
Avg.
25.7
30
117
52
1
0
0
0
0
0
0
0
0
0
0
0
0
0
53
0
0
0
0
0
0
0
0
0
0
0
0
0
0
54
0
0
0
0
0
0
0
0
0
0
0
0
0
0
55
0
0
0
0
0
0
0
0
0
0
0
0
0
0
56
1
0
0
0
30
57
1
0
0
0
0
0
0
0
0
0
0
0
0
0
58
0
0
0
0
0
0
0
0
0
0
0
0
0
0
59
0
0
0
0
0
0
0
0
0
0
0
0
0
0
60
0
0
0
0
0
0
0
0
0
0
0
1
0
0
61
1
0
0
0
0
0
0
0
1
1
1
0
0
0
62
1
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0.5
0
0
0
2.7
0
0
0
0.1
0.1
0.1
0.1
0
0
144
146
0
0
0
0
0
0
0
0
0
0
0
0
0
0
147
0
0
0
0
0
0
0
0
0
0
0
0
0
0
148
0
0
0
0
0
0
0
0
0
0
0
0
0
0
149
0
0
0
0
0
0
0
0
0
0
0
0
0
0
150
0
0
0
0
0
0
0
0
1
0
1
1
1
0
221
0
0
0
0
0
2
2
0
0
0
0
0
0
0
222
0
0
0
0
0
2
2
1
1
1
1
1
0
1
223
0
0
0
0
0
0
0
0
0
0
0
0
0
0
224
0
0
0
0
0
0
0
0
0
0
0
0
0
0
225
0
0
0
0
0
0
0
0
0
0
0
0
0
0
970
0
0
0
0
0
0
0
0
0
0
0
0
0
0
971
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0
0
0
0.3
0.3
0.1
0.2
0.1
0.2
0.2
0.1
0.1
Group C
156
63
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Sterile
64
0
0
1
0
30
Diluent
65
0
0
0
0
0
0
0
1
1
1
1
1
0
0
66
0
0
0
0
1
0
0
0
0
0
0
0
0
0
67
0
0
0
0
1
0
1
1
30
68
0
0
0
0
0
0
0
0
0
0
0
0
0
0
69
0
0
0
0
0
0
0
1
0
0
0
0
0
0
70
0
0
0
0
0
0
0
0
0
0
0
0
0
0
71
0
0
0
0
0
2
2
0
0
0
0
0
1
0
72
0
0
0
0
0
0
0
0
0
0
0
0
0
0
73
0
0
0
0
0
0
0
0
0
0
0
0
0
0
74
0
0
0
0
1
0
0
0
0
0
0
0
0
0
75
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Avg.
0
0
0.1
0
2.5
0.2
0.3
0.3
2.6
0.1
0.1
0.1
0.1
0
166
76
0
0
0
0
0
0
0
0
0
0
0
0
0
0
77
0
0
0
0
0
0
0
0
0
0
0
0
0
0
78
0
0
0
0
0
0
0
0
0
0
0
0
0
0
79
0
0
0
0
0
0
0
0
0
0
0
0
0
0
80
0
0
0
0
0
0
0
0
0
0
0
0
0
0
81
1
0
0
0
0
0
0
0
0
0
0
0
0
0
141
0
0
0
0
0
0
0
0
0
0
0
0
0
0
142
0
0
0
0
0
0
0
0
0
0
0
0
0
0
143
0
0
0
0
0
0
0
0
0
0
0
0
0
0
144
0
0
0
0
0
0
0
0
0
0
0
0
0
0
145
1
30
Avg.
0.2
2.7
0
0
0
0
0
0
0
0
0
0
0
0
Group D
JA-142
2
891
1
3
30
Passage 4
892
1
30
Avg.
1
16.5
30
106
Aborted
NA
159
883
30
884
30
Avg.
30
190
Aborted
NA
206
890
30
Avg.
30
232
888
30
889
30
Avg.
30
234
Aborted
NA
The farrowing performance results provided the most dramatic differences and similarities between the various treatment groups. Since the treatments would not have an effect on the size of the litters, the most appropriate way to compare the farrowing results would be by using percentage values. Group A had an average percentage of live/born of 85% (SD+/−9.6). Group B had an average percentage of live/born of 89% (SD+/−11.6). The control group (group C) had an average percentage of live/born of 83.4% (SD+/−7.9). The average percentages for stillborns for groups A, B and C were 8.8 (SD+/−9.66), 6.6 (SD+/−9.7), and 14 (SD+/−11.39), respectively. The average percentages of mummies born to sows of groups A, B, and C were 6.1 (SD+/−6.01), 3.9 (SD+/−4.45), and 2.6 (SD+/−4.01), respectively. The average percentages of live/born, stillborn and mummies born to the sows of group D were 8.7 (SD+/−8.92), 10.7 (SD+/−11.39), and 81.9 (SD+/−17.18), respectively.
The results of this example demonstrated the stability of the MSV, JA-142, passage 200 after being passed in the host animal six times. There were no significant differences between the group of sows treated with the MSV (group A) and those sows that were exposed to the Backpassage 6 virus (group B) in the categories of farrowing performance, leukopenia, rectal temperatures, and the clinical observations of either the sows or the piglets. In addition, the results in these same categories for the groups A and B were comparable to those achieved by group C that had been treated with sterile diluent. Finally, the performance of the sows that had been exposed to the virulent parent virus of MSV, JA-142, passage 4, clearly illustrated the level of attenuation of the MSV and the lack of reversion to virulence by the Backpassage 6, JA-142 virus.
Example 4
Materials and Methods
This example evaluated the safety and level of attenuation of administering a 10× concentration of MSV, JA-142, passage 201. The study was performed on the pregnant sow model and monitored the effect of this dosage on reproductive performance. The study consisted of three groups, A, C, and D. Group A was inoculated intra-nasally with PRRS MSV, JA-142, passage 200. Group C was inoculated intra-nasally with sterile diluent, to act as a normal control group. Group D was inoculated intra-nasally with 10× JA-142, passage 201. All inoculations were given at about 93 days gestation. Body temperatures of the sows were monitored for the first seven days following inoculation (vaccination). Blood samples were collected from the sows once a week and at time of farrowing. Prior to and following inoculation, total white blood cell counts were determined as in Example 2. The health status of each animal was monitored daily for the duration of the study up to and following farrowing for 14 days. Clinical observations of the sows were made from −1 DPV through farrowing. The farrowing performance was evaluated by observing the health status of the piglets born. PRRSV ELISA assays were preformed following the exposures of the sows with the test article. Attempts to isolate PRRSV from serum samples were performed on MA-104 cells following exposure to the test article. Clinical observations of the piglets were made from farrowing until 14 days of age. Blood samples were collected from the piglets at birth, 7 and 14 days of age. PRRSV ELISA assays were performed on the piglet sera weekly following farrowing. Piglets were also weighed at birth, day 7 post farrowing, and at necropsy. At necropsy, the lungs of each piglet were scored for percent lung involvement.
Results and Discussion
There were no significant differences between groups given a 10× dose of MSV, JA-142, passage 201, groups given a regular dose of MSV, JA-142, passage 200, and groups given sterile diluent. Therefore, based on the safety and attenuation of MSV, JA-142, passage 200 and the lack of any significant difference in the results comparing these groups, a 10× dose of MSV, JA-142, passage 201 was shown to be safe, attenuated and effective in inducing antibodies against PRRSV.
Example 5
Materials and Methods
This example demonstrated that a minimal vaccine dose of PRRSV, JA-142, passage 205, representing MSV+5, is efficacious in an experimental respiratory challenge model in feeder pigs. Pigs were divided into three groups. Group 1 was inoculated intramuscularly with PRRS MSV, JA-142, passage 205 at a titer of 2.0 logs/dose. Group 2 was inoculated intramuscularly with sterile diluent. Group 3 acted as normal controls. Pigs from groups 1 and 2 were challenged with a PRRSV isolate with an RFLP pattern of 144 on day 28 post vaccination. Body temperatures of the pigs were monitored for the first seven days following vaccination and daily following challenge. Each animal was weighed at vaccination, challenge, weekly throughout the study, and necropsy. Blood samples were collected weekly following vaccination and every two days following challenge. The health status of each animal was monitored daily for the duration of the study. At necropsy, each animal was sacrificed and the lungs were scored for percent lung involvement as in Example 2. PRRSV ELISA assays were performed following the exposures of the pigs with the test articles and challenge. Following exposure to the test articles, attempts to isolate PRRSV from serum samples were performed on MA-104 cells. Virus isolation and ELISA results were analyzed using a Chi-square analysis which tests whether the percentage of positive animals is the same in each group. White blood cell counts were performed as in Example 2.
Results and Discussion
Pigs from group 1 (vaccinated pigs) fared better in all aspects of this example than did the pigs from group 2 (pigs given sterile diluent). Clinical scores, rectal temperatures, and percent lung involvement were all higher for the pigs given sterile diluent. Weight gain and white blood cell counts were lower for the pigs receiving the sterile diluent. There was also a significant reduction in viremia beginning on day 4 post-challenge in the group given vaccine. On days 10 and 11 post-challenge, the number of animals positive for viremia decreased further in the vaccinated group, but remained the same in the group receiving sterile diluent.
An ELISA was used to monitor anti-PRRSV serological status prior to and following vaccination and challenge. All pigs were negative (S/P ratio<0.4) at the time of vaccination. All pigs including the vaccinates were negative at 7 DPV (Days Post Vaccination). Seven days later, 21 of 22 vaccinated pigs were tested as positive for antibody to PRRSV. Two pigs of group 1 remained negative during the pre-challenge period and serological converted at 8 days post challenge (8 DPC). All of the pigs in group 2 were negative at trial day 0 and remained negative throughout the pre-challenge period. On trial day 39 (8 DPC) 17 of the 22 non-vaccinated challenged pigs (Group 2) tested as sero positive. All of the pigs in group 3 (normal controls) remained sero-negative throughout the study.
Virus isolations from sera were performed before and after vaccination. Of the 22 vaccinated pigs, 17 were positive by 2 DPV, 18 were positive by 4 DPV and 19 were positive by 7 DPV. Following vaccination, vaccine virus was not recovered at all from one pig and not until 0 DPC for another. These results correspond to the sero-negative status of these pigs during the post vaccination observation period. At the time of challenge, 55% of the vaccinated pigs were viremic positive. Following challenge, this percentage rose to 82% (at 2 DPC) and gradually decreased to 9% on 11 DPC. All pigs in group 2 were negative at 0 DPC and increased to 82% positive at 2 DPC and 91% at 4 DPC. On 6 and 10 DPC, group 2 was approximately 82% virus positive and 73% of this group was positive on 11 DPC. The normal controls, group 3, remained negative for the duration of the study.
Rectal temperature monitoring showed an overall group increase experienced by group 2. One-half of the pigs in this group experienced a rise of 1° F. over the pre-challenge average for 2 or more days during the 11 day observation period. In comparison, only four of the 22 pigs in the vaccinated group experienced temperatures of 1° F. over their pre-challenge average. The average duration of those animals experiencing elevated temperatures for two or more days was 2.2 days for group 1 and 4 days for group 2. None of the pigs in group 3 experienced increases of 1° F. over their pre-challenge average for two days or longer.
Weight gain was monitored over the 11 day observation period. Pigs in group 3 gained an average of 1.06 pounds/day, pigs in group 2 gained an average of 0.94 pounds/day and pigs in group 1 gained an average of 0.53 pounds/day. Therefore, non-vaccinated challenged pigs gained only about 57% as much weight as did vaccinated challenged pigs and only 50% as much weight as the control group.
Leukopenia (white blood cell counts) were monitored during the post challenge observation period. Group 3 experienced a 5% reduction in the group average on trial day 33 (2 DPC) when compared to the pre-challenge average. For group 2, white blood cell counts dropped an average of 41% and did not return to pre-challenge levels until 11 DPC. The vaccinated group experienced a group average drop of 12% on trial day 34 (3 DPC). The counts returned to pre-challenge level on the next day and remained equal to the pre-challenge level for the duration of the observation period.
Daily clinical observations were made from trial day 28 (−4 DPC) through trial day 42 (11 DPC). All pigs were free of any observable clinical signs during the pre-challenge period. Group 3 remained free of any clinical signs for the duration of the post challenge period. Five of the pigs in group 2 were observed to have post challenge clinical signs. These signs became evident at 6 DPC and were not considered to be severe. The vaccinated pigs had only 1 clinical sign observed during the 11 day post challenge observation period.
At the termination of the study, lungs were evaluated for observable lung lesions. Group 3 had normal lungs and a group average score of 0.02. The individual pig scores for group 2 ranged from a low of 33 to a high of 98 for a group average of 78.33. The scores of the vaccinated group ranged from 30 to a high of 90 with a group average of 53.20.
The data in this example demonstrated the efficacy of a modified live Atypical PRRS viral vaccine. The vaccine was administered at a minimal dose of 2.0 logs per dose containing the fifth passage beyond the MSV (JA-142, passage 205). Efficacy of the vaccine was demonstrated by significantly reducing the extent of lung lesions, the severity of post challenge leukopenia, and post challenge fever. Additionally, a normal growth rate was maintained in vaccinated/challenged pigs compared to that achieved by the normal control pigs and significantly better than that achieved by non-vaccinated/challenged pigs.
Example 6
Materials and Methods
This example compared four groups, groups 1, 2, and 3 having twenty pigs each, and group 4 having 10 pigs. Group 1 was inoculated intramuscularly (IM) with PRRS MSV, JA-142, passage 205, at a titer of about 2.5 logs/dose. Group 2 was inoculated intra-nasally with PRRS MSV, JA-142, passage 205, at a titer of about 5.0 logs/dose. Group 3 was inoculated IM with sterile diluent. Group 4 acted as strict controls. Pigs were challenged with a PRRSV isolate from South Dakota State University (SDSU) with an RFLP pattern of 144 on day 28 post-vaccination. Body temperatures of the pigs were monitored daily following challenge. Each animal was weighed at vaccination, challenge, weekly for the duration of the study, and necropsy. Blood samples were collected weekly following vaccination and every two days following challenge. The health status of each animal was monitored daily for the duration of the study. At the termination of the study, animals were sacrificed and their lungs scored for percent lung involvement.
PPRSV ELISA assays were performed following the exposures of the pigs with the test articles and challenge. Attempts to isolate PRRSV from serum samples were also performed on MA-104 cells following exposure to the test articles. WBC counts and clinical observations were determined post inoculation as in Example 2.
Results and Discussion
At zero days post vaccination (DPV), all pigs in this example were serologically negative to PRRSV as indicated by having a S/P ratio<0.4. At 14 DPV, 70% of the pigs in group 1 and 95% of the pigs in group 2 tested positive for the presence of anti-PRRSV antibody. Only one vaccinated pig of group 1, remained sero-negative throughout the pre-challenge period. This pig became sero-positive at seven days post challenge (DPC). All of the pigs in groups 3 and 4 remained negative throughout the pre-challenge period. At nine DPC, all of the pigs in group 3, the sterile diluent treated group, tested positive by ELISA for PRRSV antibody. The normal controls, group 4, remained negative for the duration of the study.
The virus isolation results correlated well with serological results. Only one pig remained negative for virus isolation from serum and this corresponded to the sero-negative status during the post vaccination period. These results indicate a relationship between post vaccination viremia and serological conversion with vaccine dosage. Group 2 was 100% sero-positive at 14 DPV as compared to 70% for group 1. The high dose group (group 2) was 85% and 90% viremia positive at 14 and 21 DPV, respectively. In comparison, the low dose group (group 1) was 55% and 85% positive for the same test days.
Following challenge, 89% of the animals in group 3 experienced temperatures that were one degree F. or greater than the pre-challenge values for two or more days. In group 1, 75% of the animals experienced temperatures of one degree or greater for two or more days. While only 45% of the animals of group 2 experienced elevated temperatures. In comparison, 30% of the animals in the normal control group (group 4) experienced elevated temperatures for two or more days during the 11 day observation period.
Treatment with either the high vaccine dose or the low vaccine dose appeared to have no detrimental effect on the growth performance during the post-vaccination period (−3 DPV to 28 DPV). The average daily weight gain for groups 1 and 2 was 0.77 lbs./day and 0.76 lbs./day, respectively. For comparison, groups 3 and 4 had average daily weight gains of 0.77 lbs. and 0.78 lbs., respectively. Following challenge, the vaccinated groups outperformed the sterile diluent group by 0.05 lbs./day (group 1) and 0.15 lbs./day (group 2). The normal controls outgained the vaccinates during the same time period by an average of 0.4 to 0.5 lbs./day.
Eighty-four percent (16 of 19) of group 3, the sterile diluent treatment group, experienced a 25% or greater drop in their WBC count for one or more days after challenge. The normal controls had 3 of 10 (30%) that had experienced similar decreases. Following challenge, the vaccinated groups, the low dose (group 1) and the high dose (group 2) had 11 of 20 (55%) and 3 of 20 (15%) experiencing leukopenia of 25% for one or more days.
The clinical observations made prior to the challenge indicated that the pigs were of good health status. Following challenge, the level of health status did not significantly change for those pigs that were challenged (groups 1, 2, & 3). Lethargy, respiratory signs, and lost appetite were the clinical signs observed and these were described as mild in severity. The clinical signs reported for one pig in group 2 could be attributed to the bacterial pneumonia (see discussion below on lung lesions) that it was experiencing. The normal control group (group 4) was free of any observable clinical signs during the 11 day observation period.
At the termination of the study, pigs were sacrificed and the lungs were observed for PRRS-like lesions to score the extent of lung involvement. The percent of involvement was scored for each lobe then multiplied by the percent the lung represented for the total lung capacity. For example, 50% lung involvement for a diaphragmatic lobe was then multiplied by 25% to equal 12.5% of the total lung capacity. The maximum score that could be obtained was 100. The group average lung score for the normal controls (group 4) was zero. The group average score for the sterile diluent treatment group (group 3) was 70.08. The vaccinated treatment groups average scores were 48.83 for the low dose (group 1) and 17.76 for the high dose (group 2). One pig was observed to have a lung score of 62.5, the highest score within group 2. The lesions noted on this pig's lungs were described to be associated with bacterial pneumonia.
From the results of this study, both dosage levels of the atypical PRRS MSV vaccine reduced the severity of the clinical signs associated with the respiratory disease caused by the PRRSV. A full field dose outperformed the minimal dose as indicated by the significant reduction in lung lesion scores.
Example 7
Materials and Methods
This example determined the sequence of the attenuated MSV, JA-142 from the 201st passage as well as the sequence of passage 3 of the field isolate virus, JA-142. The attenuated virus isolate was obtained from the master seed stock representing the 201st passage in MA-104 simian cells of a PRRSV isolated from swine affected with PRRS.
The virus was grown on 2621 cells, a monkey kidney cell line, also referred to as MA-104 and as USU-104 (Gravell et al., 181 Proc. Soc. Exp. Biol. Med. 112-119 (1986), Collins et al., Isolation of Swine Infertility and Respiratory Syndrome Virus (Isolate ATCC VR-2332) in North America and Experimental Reproduction of the Disease in Gnotobiotic Pigs, 4 J. Vet. Diagn. Invest. 117-126 (1992)) (the teachings of which are hereby incorporated by reference). Cells were cultured in 50 ml Dulbecco modified Eagle's MEM medium (Life Technologies, Inc., Gaithersburg, Md.), supplemented with 10% fetal calf serum and 50 μg/ml gentamicin (Sigma Chemical Co., St. Louis, Mo.) in a 5% humidified CO 2 atmosphere at 37° C. in 75 cm 2 plastic tissue culture flasks. Cells were maintained by passage at 5-7 day intervals. Cells were dislodged from the surface with trypsin-versene and split 1:4. To infect cells, media was decanted and 1 ml of cell supernatant containing virus at a titer of approximately 10 5 -10 6 tissue culture infective doses (TCID 50 ) was added for 30 min. Thirty ml fresh media containing 4% fetal calf serum was added. Cells were incubated as described above for 5 days, at which time cytopathic effect was evident in the culture. Culture medium containing virus was centrifuged at 2000 rpm in a Beckman TJ6 centrifuge to pellet cellular debris.
Viral genomic RNA was purified by adding 1120 μl of prepared Buffer AVL (QIAamp Viral RNA Isolation Kit, Qiagen)(QIAGEN, Inc. Valencia, Calif.)/carrier RNA to a 280 μl sample of virus-containing culture medium. The mixture was vortexed and incubated at room temperature for 10 min. 1120 μl ethanol was added and the mixture was inverted several times. RNA was absorbed to the matrix of a QIAamp spin column by repeated centrifugation of 630 μl aliquots at 6,000×g for 1 min. The column was washed with 500 μl buffer AW and centrifuged to remove all traces of wash solution. RNA was eluted from the column with 60 μl of diethylpyrocarbonate-treated water at room temperature. Purified RNA was stored at −70° C. or used immediately for synthesis of cDNA.
For cDNA synthesis, viral RNA was heated at 67° C. for 7 min, primed with random hexamers or PRRSV-specific primers, and reverse transcribed with Superscript II RNase H − reverse transcriptase (RT) (Life Technologies, Inc.). Reactions contained 5 mM MgCl 2 , 1× standard buffer II (Perkin Elmer Corp. Wellesley, Mass.), 1 mM each of dATP, dCTP, dGTP and dTTP, 1 unit/μl of RNase inhibitor, 2 units of RT, and 1 μl of RNA in a 40 μl reaction. Reaction mixtures were incubated for 15 min at 42° C., for 5 min at 99° C. and for 5 min at 5° C.
Polymerase chain reaction (PCR) was performed to obtained DNA fragments for sequencing as follows: 10 μl portions of cDNA reaction mixture were combined with the following reagents, resulting in a 25 μl reaction containing 2 mM MgCl 2 , 1× standard buffer II (Perkin Elmer), 0.2 mM each of dATP, dCTP, dGTP and dTTP, 0.3 μM of 5′- and 3′-PRRSV-specific primer, and 0.375 units AmpliTaq Taq polymerase (Perkin Elmer). Reactions were prepared by heating for 4 min at 93° C. in a thermal cycler, then 35 cycles consisting of 50-59° C. for 30 sec, 72° C. for 30-60 sec, and 94° C. for 30 sec. Specific times and temperatures varied depending on the annealing temperatures of the primers in each reaction and the predicted length of the amplification product. A final incubation was performed for 10 min at 72° C. and reactions were placed at 4° C. PCR products were purified with a Microcon 100 kit (Amicon, Bedford, Mass.).
Rapid amplification of cDNA ends (RACE) PCR was performed to obtain the extreme 5′-end sequence of the genomic RNA, based on the method of Frohman, Mass., On Beyond Classic RACE (Rapid Amplification of cDNA Ends), 4 PCR Methods and Applications S40-S58 (1994) (the teachings of which are hereby incorporated by reference). Viral RNA was isolated and converted to cDNA as described above, with random hexamers as primers. Reaction products were purified on a Microcon 100 column (Amicon). A poly(dA) tail was added to the 3′-end by incubating 10 μl of cDNA in a 20 μl volume containing 1× buffer 4 (New England Biolabs, Beverly, Mass.), 2.5 mM CoCl 2 , 0.5 mM dATP and 2 units terminal transferase (New England Biolabs), for 15 min at 37° C. The reaction was stopped by heating for 5 min at 65° C. and then was diluted to 200 μl with water.
PCR was performed using the Expand a Long Template PCR System (Boehringer Mannheim, Mannheim, Germany) in a 50 μl reaction volume containing 10 μl of diluted, poly(dA)-tailed cDNA, 1× buffer 3, 0.35 mM each of dATP, dCTP, dGTP and dTTP, 0.625 mM MgCl 2 , 0.04 μM Q t primer (Frohman, 1994), 0.3 μM Q o primer (Frohman, 1994), 0.3 μM 5′-CGCCCTAATTGAATAGGTGAC-3′ and 0.75 μl of enzyme mix. Reactions were heated at 93° C. for 2 min in a thermal cycler and cycled 25 times with each cycle consisting of 93° C. for 10 sec, 63° C. for 30 sec, and 68° C. for 12 min. After 25 cycles, the reaction was incubated at 68° C. for 7 min and held at 4° C. An aliquot of the reaction was diluted 100-fold and 5 μl of diluted product was added to a second PCR reaction containing, in 50 μl, 1× buffer 1, 0.35 mM each of dATP, dCTP, dGTP and dTTP, 0.3 μM primer Qi (Frohman, 1994), 0.3 μM 5′-CCTTCGGCAGGCGGGGAGTAGTGTTTGAGGTGCTCAGC-3′, and 0.75 μl enzyme mix. Reactions were heated at 93° C. for 2 min in a thermal cycler and cycled 25 times with each cycle consisting of 93° C. for 10 sec, 63° C. for 30 sec, and 68° C. for 4 min. After 25 cycles, the reaction was incubated at 68° C. for 7 min and held at 4° C. Reaction products were electrophoresed on a 1% agarose gel and the band of approximately 1500 bp was purified using the QIAgen QXII gel purification kit. Eluted DNA was cloned into the pGEM-T vector (Promega, Madison, Wis.) using standard procedures. Individual clones were isolated and grown for isolation of plasmid DNA using QIAgen plasmid isolation kits.
PCR products and plasmid DNA were combined with appropriate primers based on related PRRSV sequences in Genbank or derived from known sequences, and subjected to automated sequencing reactions with Taq DyeDeoxy terminator cycle sequencing kits (Applied Biosystems, Foster City, Calif.) and a PR 2400 Thermocycler (Perkin Elmer) at the University of Minnesota Advanced Genetic Analysis Center. Reactions were electrophoresed on an Applied Biosystems 3700 DNA sequencer. Sequence base calling and proofreading were performed primarily with the Phred program (University of Washington Genome Center) and fragment assembly was performed primarily with the Phrap program (University of Washington Genome Center). Additional computer software including the Lasergene Package (DNASTAR Inc., Madison, Wis.), Wisconsin package version 9.1 (Genetics Computer Group, Madison, Wis.), and EuGene (Molecular Biology Information Resource, Houston, Tex.) was used to analyze the sequence. The final viral genomic sequence was assembled from approximately 100 PCR reactions and 428 DNA sequencing reactions.
Results
The results of Example 7 are given as SEQ ID Nos. 1 and 2 wherein SEQ ID No. 1 represents the DNA sequence of the 201 st passage of the Master Seed Virus, JA 142 and SEQ ID No. 2 represents the DNA sequence of the field-isolated virulent virus, JA 142 after three passages. Additionally, RNA sequences of the 201 st passage JA-142 and the field isolated virulent virus, JA-142 are provided as SEQ ID Nos. 3 and 4, respectively. These RNA sequences vary slightly from the DNA sequences at the 5′ end of the genome.
Example 8
Materials and Methods
This example demonstrated the presence or absence of a NspI restriction endonuclease site for differentiation between field strains of PRRSV and an attenuated strain of PRRSV. Thus, this example provides a diagnostic testing method using restriction fragment length polymorphism (RFLP) analysis. RFLP is useful as a diagnostic tool because the NspI site is present in most field strains of PRRSV. Samples, preferably of serum, should be gathered from a suspected infected individual for RT-PCR/RFLP based diagnostic testing. In this case, known virulent field strains were used for testing to provide known result standards for later diagnostic testing. While Qiagen products and specific method steps are disclosed, it is understood that other methods and products known in the art can be utilized.
For performance of the diagnostic test (and to obtain the standards disclosed below) viral genomic RNA was isolated using a QIAamp Viral RNA Isolation Kit (Qiagen, Inc. Valencia, Calif.) and following the mini spin protocol. The following steps were used:
1. Carrier RNA was added to Buffer AVL and placed at 80° C. for five minutes or until dissolution of the precipitate to form solution 1. Do not heat Buffer AVL over 5 minutes or more than 6 times. Frequent warming/extended incubation will cause degradation of carrier-RNA, leading to reduced recovery of Viral RNA and eventually false negative RT-PCR results. 2. 1120 μl of solution 1 was pipetted into a microfuge tube. 3. 280 μl of serum sample was added to the microfuge tube holding solution 1 and the resulting mixture was vortexed thoroughly to ensure that solution 1 and the sample were well mixed together. This is done to lyse the sample under highly denaturing conditions, inactivate RNases, and ensure isolation of intact viral RNA. Carrier-RNA improves binding of viral RNA to the QIAamp membrane, and limits possible degradation of the viral RNA due to any residual RNase activity. 4. This mixture was incubated at room temperature for 10 minutes. Viral particle lysis is substantially complete after lysis for 10 minutes at room temperature, although longer times may be used with little or no effect on the yield or quality of the purified RNA. 5. 1120 μl of ethanol (EtOH) (96-100%) was added to the incubated mixture and mixed thoroughly by inverting the tube several times. 6. A QIAamp spin column was placed in a 2 ml collection tube and 630 μl of the mixture obtained in step five was added. This mixture was then centrifuged at 6000×g for one minute. 7. The filtrate in the collection tube was discarded. 8. The QIAamp spin column was placed into a clean 2 ml collection tube and another 630 μl of the mixture obtained in step five was added to the spin column and centrifuged at 6000×g. 9. The filtrate in the collection tube was discarded. 10. The QIAamp spin column was placed into a clean 2 ml collection tube and another 630 μl of the mixture obtained in step five was added to the spin column and centrifuged at 6000×g. 11. 500 μl of Buffer AW1 was added to the spin column and centrifuged at 6000×g for one minute. 12. The tube containing the filtrate was discarded. 13. The spin column was placed into a clean 2 ml collection tube and 500 μl of Buffer AW2 was added and centrifuged at 18,500×g for three minutes. The filtrate was discarded. 14. The spin column was placed into a new 2 ml collection tube and centrifuged at 6000×g for one minute to remove the last traces of AW2. The filtrate was discarded. 15. The spin column was placed into a clean 1.5 ml microcentrifuge tube and 60 μl of Buffer AVE at room temperature. This mixture was incubated for one minute at room temperature before being centrifuged at 6000×g for one minute to elute the RNA. 16. The eluted RNA was pipetted into a 1.5 ml microfuge tube and stored at −70° C. if the RT-PCR is not able to be done immediately.
RT-PCR was performed on the eluted RNA obtained in the above method. A 20 μl “master mix” containing the following: 5 μl of 1×RT-PCR buffer, 1 μl of 0.4 mM DNTP mixture (containing equal amounts each of dATP, dCTP, dGTP and dUTP), 0.1 μl of 0.08 units/Rx RNAse inhibitor, 0.5 μl 500 nM BVDV forward primer, 0.5 μl 500 nM BVDV reverse primer, 11.9 μl RNAse/DNAse free water, and 1 μl Qiagen “secret” enzyme mix was added to a tube. 5 μl of the eluted RNA was then added to the tube.
Reactions were initially heated at 50° C. for 30 minutes followed by heating at 95° C. for 15 minutes in a thermal cycler and then cycled 35 times with each cycle consisting of 57° C. for 30 seconds, 72° C. for 45 seconds, and 94° C. for 45 seconds. After 35 cycles, the reaction was incubated at 57° C. for 30 seconds followed by 72° C. for 7 minutes and finally held at 4° C. To check the PCR on an agarose gel, 1 g of agarose was added to 100 ml of 1×TAE buffer before microwaving on high for two minutes. Next, 4 μl of 10 mg/ml EtBr was added to the heated gel before casting the gel and allowing it to solidify for 15-30 minutes. 4 μl of the PCR product was mixed with 1 μl loading dye. 3.5 μl of a 1 Kb ladder was added to 13.2 μl of water and 3.3 μl of loading dye for use as a marker. 4 μl of the marker mixture was electrophoresed on the gel, indicating a 1 Kb product. A band from the PCR product should be approximately 1 Kb in size. The gel was then run at 140 volts for 1 hour or 75 volts for two hours.
The band of approximately 1 Kb was purified using the QIAgen Qiaquick PCR Purification Kit (Qiagen, Inc. Valencia, Calif.). A column was placed in a collection tube and 20 μl PCR reaction sample and 100 μl PB buffer were added. This mixture was mixed thoroughly before spinning for 1 minute at full speed in an Eppendorf microfuge. The flow-through products were discarded and the column was replaced in the tube. The tube was spun for another full minute and allowed to stand for at least one minute at room temperature. The column was then spun a third time at full speed. The eluent remaining contains purified PCR product and water.
The PCR/water product from above was then digested with Nsp I, a restriction enzyme and then electrophoresed on a 1.5% agarose gel to determine fragment numbers and lengths.
Results
The results of Example 8 are used for diagnostic results. It was found that most of the field strains for the PRRS virus contain one Nsp I restriction site, therefore yielding digestion products of 549 and 476 bp from the 1 Kb RT-PCR product. The parent strain of the JA-142 passage 200 possesses this phenotype. Only one PRRS strain, BI-Vetmedica 142 passage 200 (+5), contains two Nsp I sites, yielding digestion products of 476, 380, and 173 bp from the 1 Kb RT-PCR product. Some field strains possess no Nsp I site within this RT-PCR product, and therefore exhibit no digestion and electrophoresis of one fragment of 1021 bp. Thus, the presence of the attenuated virus can be determined.
Example 9
Materials and Methods
This Example tested the degree of protective immunity against maternal reproductive failure of swine vaccinated by one or two attenuated strains of PRRSV.
Fifty gilts were separated into five experimental groups designated A-E and having ten gilts in each group. Gilts of group A were neither vaccinated nor challenged and were therefore used as strict controls. Gilts of group B were used as the challenge controls and therefore received no vaccinations but were challenged at or about day 90 of gestation. Gilts of groups C, D, and E were each vaccinated twice before conception with one month between vaccinations. These gilts were then challenged at or about day 90 of gestation. Two strains of vaccine virus (strains RespPRRS/Repro and JA-142) were used to challenge the gilts. The challenge consisted of oronasal exposure to virulent PRRSV. Gilts of group C were vaccinated twice with strain RespPRRS/Repro. Gilts of group D were vaccinated first with RespPRRS/Repro and then with JA-142. Gilts of group E were vaccinated twice with strain JA-142. Gilts and their progeny were observed at least twice daily for clinical signs and tested for both PRRSV and homologous antibody at selected intervals. The gilts of groups C, D, and E were bled just before their first vaccination and at selected times thereafter until they were necropsied, usually at or about 14 days after farrowing or sooner if they aborted. Gilts of group A and B were bled just before challenge and at identical selected times thereafter. Beginning one month after the second vaccination of groups C, D, and E, all gilts were bred as they came into estrus. All of the boars used for breeding purposes were free of antibody against PRRSV. Near the time of challenge, each gilt was moved to an isolation room and was kept in isolation until the experiment was ended for that gilt and her litter at two weeks after farrowing or sooner in the case of abortion or premature death of all progeny. All surviving pigs were weighed when they were two weeks old. Gilts that failed to conceive at their first, second, or third estrocycle were excluded from the experiment. This reduced the numbers of pregnant gilts for groups B, C, D, and E to 9, 8, 9, and 9, respectively. The same limitation did not apply to group A because for this group, there were more than ten nonvaccinated gilts available from which to make a random selection for inclusion in group A.
Results and Discussion:
All vaccinated gilts (groups C, D, and E) responded to vaccination with the production of antibodies against PRRSV. These results are provided in FIG. 1 which is a graph representing the ratio of the total number of samples to samples positive for PRRSV antibodies. Blood samples were collected from the gilts just before their first vaccination and at selected times thereafter during an interval of 196 days. Depending on when gilts conceived (breeding was started on day 60), they were progressively removed from this group. Beginning at or about 90 days of gestation, blood samples were collected just before they were challenged, seven days after challenge, fourteen days after challenge, at the time of delivery (which was at or about 24 days after challenge if the gilt farrowed normally, or sooner if the gilt aborted), and at the time of necropsy (which was at or about 38 days, i.e. 2 weeks after farrowing, or sooner if the gilt lost all of her live born pigs before 2 weeks after farrowing). These results are provided in FIG. 2 .
As shown in FIGS. 1 and 2 , antibody levels increased after challenge for groups B, C, D, and E. For group B, the nonvaccinated group, these antibodies appeared only after challenge while they were present prior to challenge for groups C, D, and E. Gilts of group A and all boars used for breeding both vaccinated and nonvaccinated gilts remained free of antibody against PRRSV throughout the experiment. None of the vaccinated gilts had any obvious vaccine-related clinical signs after vaccination. Conversely, all of the gilts (both vaccinated and nonvaccinated) had moderate to severe clinical signs following challenge. A summary of the number of live born and still born pigs, the number of aborted, late term dead, and mummified fetuses, and the number and weight of pigs still alive 14 days after farrowing is presented in Table 4. All of the pigs of groups C, D, and E that survived through day 14 were robust and were judged to be in excellent health. None of these pigs yielded infectious virus from either serum or lung lavage samples. In contrast, all pigs of group B that survived through day 14 were unthrifty and were shown by virus isolation to be infected. A measure of the difference in general health is provided by the relative body weights of pigs of group B versus those of pigs of groups A, C, D, and E. The appearance of pigs of group B suggested that few, if any, would have recovered or would have recovered sufficiently to warrant any expectation of their continued survival under conditions of commercial swine production.
TABLE 4
Effect of Vaccination Against Porcine Reproductive and Respiratory Syndrome Virus
(PRRSV) on the Health and Survival of Fetuses and Pigs of Gilts Subsequently Exposed
to Highly Virulent PRRSV
Day 14 2
Day 0 1
Mean
Late-term
Mean pig
litter
Liveborn
Stillborn
dead
Mummified
Aborted
Live
weight
weight
Group
Gilts 3
pigs
pigs
fetuses
fetuses
fetuses
pigs
(lbs)
(lbs)
A
10
102
17
1
2
0
95
9.8
93.1
B
9
24
3
62
5
0
16
5.6
10.0
C
8
37
8
31
4
13
27
11.1
37.5
D
9
47
10
14
0
39
38
8.7
36.7
E
9
50
13
38
3
0
33
10.4
38.1
1 At the time of farrowing.
2 On the day the experiment was ended.
3 Pregnant gilts that aborted or farrowed.
Vaccination with either strain (RespPRRS/Repro and JA-142) of attenuated PRRSV provided a level of protective immunity that was demonstrated by challenge exposure. Although protection was incomplete regardless of the vaccine strain or method of vaccination, it was sufficient to recommend vaccination as an economically beneficial procedure. Whereas the loss of pigs of group B was essentially complete either due to death or ill health, about 40% of the pigs of litters of groups C, D, and E (on a per litter basis and using 100% as the value for litters of group A) would have survived to market. The excellent health status of the surviving pigs of groups C, D, and E is emphasized by the fact that the mean body weight of pigs of these groups (when calculated collectively) is the same as that of pigs of group A. The economic impact of saving about 3.6 pigs/litter through vaccination is difficult to project with certainty, however, if a reasonable assumption is made that each pig is worth about $20.00 in profit and reduced overhead through sharing of fixed costs, then two vaccinations at an estimated cost of about $1.00 each would return $72.00 for each $2.00 invested. On the basis of these assumptions, anything more than a prevalence of PRRSV-induced reproductive failure of one case for every 36 pregnancies (or a severe clinical epidemic once every 18 months assuming 2 pregnancies/year) would make vaccination cost effective. Moreover, it seems likely that the results of this study present the worst case scenario. Namely, the strain used for challenge was selected to represent the most virulent field strains of PRRSV currently present in North America and may not accurately reflect the majority of field strains against which vaccines are likely to be more protective. | Substantially avirulent forms of atypical porcine reproductive and respiratory syndrome (PRRS) virus and corresponding vaccines are provided which result from cell culture passaging of virulent forms of PRRS. The resultant avirulent atypical PRRS virus is useful as a vaccine in that PRRS specific antibody response is elicited by inoculation of host animals, thereby conferring effective immunity against both previously known strains of PRRS virus and newly isolated atypical PRRS virus strains. The preferred passaging technique ensures that the virus remains in a logarithmic growth phase substantially throughout the process, which minimizes the time required to achieve attenuation. The present invention also provides diagnostic testing methods which can differentiate between animals infected with field strains and attenuated strains of PRRSV. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention concerns the knitting and sewing arts and more particularly relates to a unique tool for use in grabbing a loose thread and positioning the thread for securement within the needlework.
2. Background of the Prior Art
Loose threads will invariably appear on the back mesh of any needlework project. Such loose threads result from waste knots, cut out stitches and the like. Such threads, if left unattended, are unsightly and will tend to unravel the work as a whole. In order to prevent such results, the loose threads need to be tied down or otherwise need to be secured.
The threads can be secured in one of two ways. The end of the loose thread nearest the mesh can be tied down and snipped in order to prevent travel of the thread through the mesh. Although this method of tie down and cutting of the loose thread is effective, it is very difficult to practice. Most loose threads tend to be of relatively short length such that only a highly skilled vascular surgeon could knot the thread. Furthermore, this method can result in an unsightly project and is ineffective when a large-spaced mesh is utilized.
The second method of thread securement is to position the loose thread underneath existing stitches within the needlework project. The stitches securely hold the thread in place and prevent unraveling. However, as the existing stitches are relatively tight, positioning of the loose threads thereunder can be quite challenging.
In order to accomplish this task, most individuals attempt to position the loose thread with the help of a needle that is used as a "lifter" of the threads. Such a method, inefficient and difficult at best, runs a strong risk of cutting existing stitches or mesh.
A device is needed to assist an individual in tying down loose threads in a needlework project. The device should be relatively quick and simple to use and should not cause any damage to the existing needlework. Ideally, such a device should be of relatively simple and inexpensive construction.
SUMMARY OF THE INVENTION
The thread positioner of the present invention meets the aforementioned needs in the art. The present invention provides a thread positioner that grabs a loose thread of a needlework project and positions the loose thread underneath existing stitching.
The thread positioner of the present invention comprises a guide loop that is inserted through one or more existing stitches on the needlework project with the end of the guide loop protruding beyond the target stitches. A thread grabber passes through the guide loop and grabs the loose thread. Once the thread is grabbed, the thread grabber is retracted from the guide loop depositing the loose thread between the edges of the guide loop. Once the loose thread is thus deposited, the guide loop itself, with loose thread in tow, is retracted from within the target stitch or stitches and thereby permanently depositing the loose thread within the stitches.
The thread positioner is quick and simple to use. The device does not damage the needlework or material and leaves the loose thread tied down with a neat and clean appearance.
The device is very simple and relatively inexpensive to construct.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a a front elevation view of the thread positioner of the present invention.
FIG. 2 is a side elevation view of the thread positioner of the present invention.
FIG. 3 is an exploded view of the guide loop with a releasably attachable connection means.
FIG. 4 is a cutaway view of the guide means illustrated in FIG. 1.
FIG. 5 is a cutaway view of the guide means illustrated in FIG. 2.
Similar reference numerals refer to similar parts throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, it is seen that the thread positioner of the present invention, generally denoted by reference numeral 10, is comprised of a guide means having a guide loop 12. The guide loop 12 is a resilient member made from wire, plastic or other similar material. The guide loop 12 is attached to a finger grip 16 by any appropriate method. As seen in FIGS. 4 and 5, the finger grip 16 can have a hollow channel 20, with a first opening 22 and a second opening 24, disposed therein. The guide loop 12 is disposed and secured within the hollow channel 20 through the first opening 22. It is recognized that the guide loop 12 can be attached to the finger grip 16 by any other appropriate means. It is noted that while the finger grip 16 is illustrated as an ornamental heart, the finger grip 16 can be configured in any appropriate shape and design to facilitate holding of the finger grip 16 by a user.
A first keyhole 18 is disposable within the second opening for insertion of a chain or string (neither illustrated) therethrough. An optional second keyhole 28 is securable to the finger grip 16 at any appropriate point on the finger grip 16 including disposed within the first opening 22.
A thread grabber is comprised of a shaft having a proximal end 36 and a distal end 38, having a hook 40 thereon. The proximal end 36, which can be ornamentally designed, serves as a finger grip. An optional third keyhole 34 is attached to the end of the proximal end 36.
A connection means 32 connects the thread grabber to the finger grip 16 of the guide loop 12. The connection means 32 be any appropriate flexible or semi-flexible material such as the illustrated chain as well as string, an elongate piece of plastic, rubber, or neoprene, among others. The connection means 32 can be either releasably or securely attached to the finger grip 16 and can be either releasably or securely attached to the thread grabber. If the connection means 32 is releasably attached to the finger grip 16, any appropriate method can be employed to provide the releasable attachment. As an example, a clasp 30, located on the end of the connection means 32 can receive the optional second keyhole 28. If the connection means 32 is releasably attached to the thread grabber, any appropriate method can be employed to provide the releasable attachment including a clasp 30 receiving the optional third keyhole 34. Additionally, the connection means 32 can be retachably separable along its length.
In order to utilize the thread positioner 10, the guide loop 12 is inserted through the target stitch or stitches within which the loose thread will eventually be secured. The end of the guide loop 12 extends beyond the final stitch and terminates near the loose thread to be positioned and secured. The thread grabber is inserted through the guide loop 12. The hook 40 is used to grab the loose thread. Once so grabbed, the thread grabber, with the loose thread secured by the hook 40, is retracted with loose thread in tow from within the guide loop 12. The loose thread is now positioned within the guide loop 12. Thereafter, the guide loop 12 is withdrawn, with loose thread in tow, from the stitches. Once the guide loop 12 is fully withdrawn, the loose thread is securely positioned within the target stitches.
If the loose thread is found on the front side, as opposed to the back side, of the material, the device 10 is used to retrieve the loose thread to the back side where the loose thread can then be securely positioned as described above. In order to accomplish this task, the guide means is separated from the thread grabber. The guide loop 12 is positioned on the back side of the material and is pushed through the material so that the guide loop's end is located on the front side of the material proximate the loose thread. Thereafter, the thread grabber is inserted through the guide loop 12 and the hook 40 is used to grab the loose thread. The thread grabber is then retracted so that the loose thread is positioned within the guide loop 12 in the usual way. With the loose thread now positioned within the guide loop 12, the guide loop 12 is pulled out of the material pulling the loose thread to the back side of the material. The loose thread, now located at the back side of the material, is now ready for secure positioning within the stitching.
While the invention has been particularly shown and described with reference to an embodiment thereof, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention. | A thread positioner comprises a guide loop, having a finger grip, that is insertable through one or more stitches of a needlework project. A thread grabber is insertable through the guide loop and grabs a loose thread and is thereafter withdrawn, positioning the loose thread within the guide loop. The guide loop is withdrawn from the stitches positioning the loose thread therewithin. | 3 |
FIELD OF THE INVENTION
The present invention relates to a well stimulation tool for oil and/or gas production. More specifically, the invention is a hydraulically-actuated propellant stimulation downhole tool for use in a hydrocarbon well.
BACKGROUND
In hydrocarbon wells, fracturing (or “fracing”) is a technique used by well operators to create and/or extend a fracture from the wellbore deeper into the surrounding formation, thus increasing the surface area for formation fluids to flow into the well. Fracing may be done by either injecting fluids at high pressure (hydraulic fracturing), injecting fluids laced with round granular material (proppant fracturing), or using explosives to generate a high pressure and high speed gas flow (TNT or PETN up to 1,900,000 psi) known as propellant stimulation.
Gas generating propellants have been utilized in lieu of hydraulic fracturing techniques as a more cost effective manner to create and propagate fractures in a subterranean formation. In accordance with conventional propellant stimulation techniques, a propellant is ignited to pressurize the perforated subterranean interval either simultaneous with or after the perforating step so as to propagate fractures therein. Typically, the propellant material is ignited due to shock, heat, and/or pressure generated from a detonated charge. Upon burning, the propellant material generates gases that clean perforations created in the formation by detonation of the shaped charge and which extend fluid communication between the formation and the wellbore.
SUMMARY
In one embodiment there is provided a downhole tool comprising a detonation section for stimulating a hydrocarbon-producing formation. The detonation section comprises a first end, a second end, a propellant volume located proximate to the second end, and a wall. The wall has an inner surface, an outer surface, a rupture disc and an actuating assembly. The inner surface defining a central bore extending from the first end to the second end. The outer surface is exposed to a well annulus during operation of the downhole tool. The actuating assembly comprises a detonator chamber, a detonator assembly, a firing pin and a flow passage. The detonator chamber has a first end positioned adjacent to the propellant volume and a second end having an inlet. The detonator assembly is located within the detonator chamber proximate to the first end of the detonator chamber. The firing pin is located within the detonation chamber. The firing pin is retained proximate to the inlet until an actuating pressure is applied through the inlet. The flow passage is contained between the inner surface and the outer surface and is in fluid flow communication with the detonation chamber through the inlet. The rupture disc is positioned between the flow passage and the central bore such that it prevents fluid flow communication between the flow passage and the central bore until ruptured by the application of the actuating pressure in the central bore.
Additionally, in the above-described downhole tool, the flow passage can be contained between the inner surface and the outer surface so as to be entirely interior to the wall. The firing pin can be retained proximate to the inlet by a shear pin such that the shear pin holds the firing pin back from the detonator until the actuating pressure is applied through the inlet.
In a further embodiment of the above-described downhole tool, the wall can have a plurality of actuating assemblies spaced about the circumference of the wall. The flow path of each actuating assembly can be in fluid flow communication with a circumferential chamber, which is in fluid flow communication with the central bore when the rupture disc is ruptured such that fluid is distributed to each flow path through the circumferential chamber. Additionally, there can be no more than one rupture disc associated with the circumferential chamber and the plurality of actuating assemblies.
In another embodiment of the above described downhole tool, there can be a plurality of detonation sections arranged sequentially such that the central bore of each section aligns to form a continuous central bore running through the plurality of sections.
In still yet another embodiment, there is a downhole tool comprising a detonation section for stimulating a hydrocarbon-producing formation. The detonation section comprises a first end, a second end, a propellant volume and a wall. The propellant volume is located proximate to the second end. The wall has an inner surface and an outer surface. The inner surface defines a central bore extending from the first end to the second end. The outer surface is exposed to a well annulus during operation of the downhole tool. The wall is comprised of a first wall element connected to a second wall element so as to form a circumferential chamber running circumferentially through the wall. The first wall element having a plurality of actuating assemblies. Each actuating assembly comprises a detonator, a detonator assembly, a firing pin and a flow path. The detonator chamber having a first end positioned adjacent to the propellant volume and a second end having an inlet. The detonator assembly is located within the detonator chamber proximate to the first end of the detonator chamber. The firing pin is located within the detonation chamber. The firing pin is retained proximate to the inlet until an actuating pressure is applied through the inlet. The first flow passage is contained between the inner surface and the outer surface and extends from the circumferential chamber to the inlet of the detonation chamber. The first flow path is in fluid flow communication with the detonation chamber through the inlet and is in fluid flow communication with the circumferential chamber. The second wall element has a second flow passage extending from the circumferential chamber to the inner surface so as to provide fluid flow communication between the central bore and the circumferential chamber. The rupture disc is positioned in the second flow passage such that the rupture disk prevents fluid flow communication between the circumferential chamber and the central bore until ruptured by the application of the actuating pressure in the central bore.
In the above-described downhole tool, the rupture disc can be positioned adjacent to the inner surface. Also, the first flow passage and the second flow passage can be contained between the inner surface and the outer surface so as to be entirely interior to the wall. Additionally, there can be a plurality of detonation sections arranged sequentially such that the central bore of each section aligns to form a continuous central bore running through the plurality of sections.
In a further embodiment of the above-described downhole tool, the firing pin can be retained proximate to the inlet by a shear pin such that the shear pin holds the firing pin back from the detonator until the actuating pressure is applied through the inlet.
In still another embodiment, there is provided a method comprising:
(a) introducing a casing string into a wellbore extending through at least one subterranean region having hydrocarbon deposits, wherein the casing string comprises a tubular wall defining an annular region between the tubular wall and the wellbore, and a central bore, which extends through at least one detonation section; (b) increasing the pressure in the central bore such that rupture discs located within the tubular wall are ruptured thus detonating a propellant volume such that the subterranean region around the wellbore is fractured.
Further, the detonation can be accomplished by an increase in pressure carried out under substantially static downhole tool conditions to rupture the rupture disc. The method can further comprise after step (a) and prior to step (b), introducing cement into the annular region to thus cement the casing in the wellbore. Also, step (b) can further comprise perforating the cement.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of a detonation section of a downhole tool in accordance with an embodiment.
FIG. 2 is a sectional elevation through section line 2 - 2 of FIG. 1 .
FIG. 3 is a sectional elevation through section line 3 - 3 of FIG. 1 .
FIG. 4 is an enlargement of the circumferential flow channel section of the embodiment of FIG. 1 .
FIG. 5 is an enlargement of the rupture disc section of the embodiment of FIG. 1 .
FIG. 6 is an enlargement of the firing pin retainment section of the embodiment of FIG. 1
FIG. 7 is a sectional elevation of the pressure chamber and firing pin of the embodiment of FIG. 1 prior to actuation of the firing pin.
FIG. 8 is a sectional elevation of the pressure chamber and firing pin of the embodiment of FIG. 1 after actuation of the firing pin.
FIG. 9 is an illustration of a downhole tool comprising a casing string utilizing an embodiment of the invention; the downhole tool having been lowered into a wellbore.
FIG. 10 is an illustration of the downhole tool of FIG. 9 after cementing of the casing string within the wellbore.
FIG. 11 is an illustration of the downhole tool of FIGS. 9 and 10 after firing of the propellant.
DETAILED DESCRIPTION
In the description that follows, like parts are marked throughout the specification and drawings with the same reference numerals, respectively. The drawings are not necessarily to scale and the proportions of certain parts have been exaggerated to better illustrate details and features of the invention. In the following description, the terms “upper,” “upward,” “lower,” “below,” “downhole” and the like as used herein shall mean in relation to the bottom or furthest extent of the surrounding wellbore even though the well or portions of it may be deviated or horizontal. The terms “inwardly” and “outwardly” are directions toward and away from, respectively, the geometric center of a referenced object. Where components of relatively well-known designs are employed, their structure and operation will not be described in detail.
Turning now to FIG. 1 , one embodiment of a detonation section 10 for a downhole tool is illustrated. Detonation section 10 is comprised of a wall 12 . Wall 12 typically is a cylindrical wall having an inner surface 14 and an outer surface 16 . Inner surface 14 defines a central bore 18 , typically a cylindrical bore, extending from a first end 20 to a second end 22 of detonation section 10 . As can be seen from FIG. 1 , central bore 18 extends continuously through detonation section 10 . Outer surface 16 is exposed to the well annulus during operation of the downhole tool in a wellbore. The well annulus is the region between the downhole tool and the wellbore wall or the inner casing wall of the wellbore. Additionally, first end 20 is configured to connect to other components of the downhole tool or a casing string and second end 22 can be configured to connect to additional components of the downhole tool or a casing string.
Generally, detonation section 10 and wall 12 will be made up of one or more wall elements or sleeves. As illustrated, detonation section 10 has first wall element or first sleeve 26 , and second wall element or second sleeve 28 . First sleeve 26 and second sleeve 28 are configured such that when connected they form circumferential flow channel 30 , which can better be seen with reference to FIGS. 3 and 4 . O-rings 29 provide a fluid tight seal between first sleeve 26 and second sleeve 28 . As can be seen from FIG. 3 , circumferential flow channel 30 extends circumferentially around the interior of wall 12 such that it is entirely interior to wall 12 . Circumferential flow channel 30 is in fluid flow connection via flow passage 32 to a rupture disc chamber 34 . Flow passage 32 is entirely interior to wall 12 . As used herein, “entirely interior to wall 12 ” means residing within wall 12 so as not to have a flow passage or channel wall in addition to the wall 12 wherein such separate flow passage or channel wall would be exposed to the interior central bore 10 or the annular region 74 (see FIG. 9 ). Thus, “entirely interior to wall 12 ” excludes tubes or passages running along inner surface 14 or outer surface 16 of wall 12 .
Rupture disc chamber 34 , which can be better seen with reference to FIG. 5 , can be accessed through a plug 36 accessible from and forming a part of outer surface 16 . In operation of the downhole tool, rupture disc chamber 34 will be sealed by plug 36 such that rupture disc chamber 34 is entirely interior to wall 12 . Rupture disc 38 can be positioned adjacent to inner surface 14 of wall 12 . Rupture disc 38 provides a second seal for rupture disc chamber 34 such that, when in place, rupture disc 38 prevents fluid flow communication between flow passage 32 and central bore 18 through rupture disc chamber 34 . When rupture disc 38 is ruptured by a predetermined pressure within central bore 18 , fluid flow communication is established between flow passage 32 and central bore 18 . In an additional embodiment, rupture disc chamber 34 and flow passage 32 are not used, and the rupture disc is located in the first wall element 26 at the circumferential flow channel so that the rupture disc is directly between the circumferential flow channel 30 and central bore 18 . In another embodiment, multiple rupture discs are associated with circumferential flow channel 30 ; typically, with a flow passage and rupture disc chamber also associated with each rupture disc. However, it is presently preferred and considered advantageous that there is no more than one rupture disc associated with the circumferential flow channel 30 .
Returning to FIG. 1 , a propellant region 40 of wall 12 comprises a ported sleeve 48 and a portion of wall 12 which serves as an internal sidewall 42 of the propellant region 40 . A cylindrical propellant volume 44 is adjacent to and between the internal sidewall 42 and ported sleeve 48 . Ported sleeve 48 has a plurality of circular pressure ports 46 (shown in FIGS. 9, 10 and 11 ) therein to direct and shape the gases and emissions generated during detonation of the propellant volume 44 . Typically ports 46 are spaced equally radially around ported sleeve 48 .
As can be seen with reference to FIGS. 1, 2, 6, 7 and 8 , one or more actuating assemblies 50 are contained at least partially and generally entirely within wall 12 . As best seen from FIG. 7 , each actuating assembly 50 comprises a detonator chamber 52 having a first end 51 positioned adjacent to a propellant volume 44 . Each actuating assembly 50 also has a second end 53 , which has an inlet 54 . Within detonator chamber 52 are detonator assembly 56 and firing pin 58 . Detonator assembly 56 is located proximate to first end 51 so as to be able to detonate propellant volume 44 when activated by firing pin 58 . Firing pin 58 is retained proximate to inlet 54 by a shear pin 60 .
A flow passage 62 extends from inlet 54 to circumferential flow channel 30 and can be entirely interior to wall 12 . Flow passage 62 places inlet 54 in fluid flow communication with circumferential flow channel 30 such, when rupture disc 38 is ruptured, inlet 54 is in fluid flow communication with central bore 18 . Prior to the rupturing, rupture disc 38 prevents fluid flow communication with central bore 18 .
The detonator assembly 56 includes a primer 80 , primer case 82 , shaped charge 84 and an isolation bulkhead 86 . The primer 80 is spaced from the firing pin 58 within the primer case 82 . The shaped charge 84 is positioned adjacent to the primer case 82 opposite from primer 80 . The isolation bulkhead 86 is positioned adjacent the shaped charge 84 and proximate to the propellant volume 44 . In this position, detonation of the shaped charge 84 will cause corresponding ignition of the propellant volume 44 .
FIG. 8 illustrates the actuating assembly after detonation. By applying a predetermined pressure, rupture disc 38 is ruptured and fluid flow communication is established between inlet 54 and central bore 18 . Prior to the rupturing, firing pin 58 is in a first position proximate to inlet 54 . Upon the rupturing, the fluid introduced to inlet 54 at the predetermined pressure causes firing pin 58 to move towards detonator assembly 56 because of the pressure differential established across firing pin 58 . The pressure differential is maintained by seal rings 61 . In other words, the portion of detonation chamber 52 adjacent to first end 57 of firing pin 58 is at a first pressure, which is equal to or greater than the pressure at inlet 54 prior to rupturing of rupture disc 38 . After rupturing of the rupture disc 38 , the pressure at the inlet 54 increases to the predetermined pressure, which is greater than the first pressure. The pressure differential is great enough to move firing pin 58 and, thus, shear the shear pin 60 , which allows firing pin 58 to move to a second position contacting and detonate primer 80 . Detonation of primer 80 is contained by primer case 82 and causes detonation of the adjacent shaped charge 84 , which transfers explosive energy to the propellant volume 44 , causing ignition thereof. The explosive energy is directed radially outwardly in the form of pressure waves through ports 46 (see FIGS. 9 to 11 ) and into the surrounding subterranean formation.
As can be best seen from FIG. 2 , there can be a plurality of actuating assemblies associated with circumferential flow channel 30 . In FIG. 2 , firing pin 58 can be seen within a plurality of detonation chambers 52 . Each detonation chamber 52 would be in fluid flow communication with the same circumferential flow channel 30 by separate flow passages 62 as described above. Each detonation chamber 52 and associated flow passage 62 would generally be spaced symmetrically around the interior of wall 12 .
Also, as can best be seen from FIG. 9 , there can be a plurality of detonation sections 10 on a downhole tool or casing string. In FIG. 9 , a casing string 70 comprises casing 71 and at least two detonation sections 10 a and 10 b . Additionally, the casing string 70 can have tools 72 a and 72 b , which, for example, can be a packer such as used during cementing operations or other similar tools. As will be realized from FIG. 9 , casing 71 , tools 72 a and 72 and detonation sections 10 a and 10 b can each have central bores 18 , which can be aligned sequentially so that the central bores 18 of each form a continuous central bore running through downhole tool or casing string 70 .
With reference now to FIGS. 9, 10 and 11 , a process using an embodiment of the downhole tool will now be described. In FIG. 9 a casing string 70 is introduced into wellbore 64 having a wall 66 . Wellbore 64 extends through at least one subterranean region 68 having hydrocarbon deposits. As shown, the wellbore 64 extends through at least two such subterranean regions 68 a and 68 b . The casing string comprises a tubular wall 12 defining an annular region 74 between tubular wall 12 and wellbore wall 66 . The casing string also comprises a central bore 18 . The central bore 18 extends continuously through detonation sections 10 a and 10 b and can extend continuously through the length of the casing string 70 . As shown, the detonation sections 10 a and 10 b of casing string 70 are placed adjacent to subterranean regions 68 a and 68 b , respectively. Each detonation section is located adjacent to a subterranean region having hydrocarbon deposits. It will be appreciated for some applications, more than one detonation section will be adjacent the same subterranean region.
After introducing of casing string 70 into wellbore 64 , casing string 70 can be cemented in wellbore 64 as shown in FIG. 10 . Cement 76 can be introduced into annular region 74 to thus cement the casing string 70 in the wellbore 64 . Cement 76 can be introduced in accordance with methods known in the art.
After cementing operations, if any, are completed, perforation and/or fracing can be performed as illustrated in FIG. 11 . The fluid pressure in the central bore 18 is increased to a predetermined pressure or greater such that rupture discs, located within tubular wall 12 and exposed to the central bore 18 , are ruptured. By rupturing the rupture discs, inlet 54 to detonation chamber 52 is exposed to the predetermined fluid pressure, thus, moving the firing pin and detonating the propellant volume 44 , as described above. The detonation of the propellant volume is such that the cement located adjacent to the detonation sections 10 a and 10 b is perforated 90 , and/or subterranean regions adjacent to wellbore 64 is fractured 92 . As will be appreciated, the detonation is accomplished by an increase in pressure carried out under substantially static downhole tool conditions to rupture said rupture disc. By “static downhole tool conditions” it is meant the rupturing of the disc and movement of firing pin by increased fluid pressure actuates the detonation without the necessity of further mechanical or electrical movement or actuating of the downhole tool such as by movement of sleeves, valves or other mechanical apparatuses.
While various embodiments have been shown and described herein, modifications may be made by one skilled in the art without departing from the spirit and the teachings herein. The embodiments described herein are exemplary only, and are not intended to be limiting. Many variations, combinations, and modifications are possible. Accordingly, the scope of protection is not limited by the description set out above, but is defined by the claims which follow, that scope including all equivalents of the subject matter of the claims. | A hydraulically-actuated propellant stimulation of a downhole tool for use in hydrocarbon wells, which comprises a rupture disc that allows a predetermined pressure in the central bore of the tool to actuate a detonator assembly and, thereby, detonating a propellant volume. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to a drug delivery matrix coating, to an implantable device comprising the drug delivery matrix coating, to a method for making the drug delivery matrix coating and to a method for applying the drug delivery matrix coating to a stent.
Stents are typically implanted within a vessel in a contracted state and expanded when in place in the vessel in order to maintain patency of the vessel to allow fluid flow through the vessel. Typically, implantation of such stents is accomplished by mounting the stent on the balloon portion of a catheter, positioning the stent in a body lumen, and expanding the stent to an expanded state by inflation of a balloon within the stent. The stent can then be left in place by deflating the balloon and removing the catheter.
Because of the mechanical strength that is required to properly support vessel walls, stents are typically constructed of metallic materials. However, it is frequently desirable to provide localized pharmacological treatment of a vessel at the site being supported by the stent. It is convenient to employ the stent as a vehicle for drug delivery. The metallic materials are not capable of carrying and releasing drugs. Polymeric materials capable of absorbing and releasing drugs typically do not fulfill the structural and mechanical requirements of a stent, especially when the polymeric materials are loaded with a drug, since drug loading of a polymeric material diminishes the structural and mechanical properties of the polymeric material. Since it is often useful to provide localized therapeutic pharmacological treatment of a vessel at the location being treated with the stent, it is desirable to combine such polymeric materials with existing stent structures to provide a stent with the capability of absorbing therapeutic drugs or other agents, for placement and release of the therapeutic agents at a specific intravascular site.
One solution historically used has been coating a stent's metallic structure with a polymeric material in order to provide a stent capable of both supporting adequate mechanical loads as well as delivering drugs. Techniques typically used to join polymers to metallic stents include dipping, spraying and conforming processes. However, these techniques have tended to introduce other problems into the stent products. Other problems with drug delivery matrix coatings include marginal adhesion to a substrate such as a metal substrate, insufficient elongation of the coating resulting in cracks, and limited and sub-optimal solvent choices that result in difficult application of the coating and poor manufacturability.
SUMMARY OF THE INVENTION
The present invention relates to a copolymer of carboxylic acid in a layer as applied in a drug releasing implant. The carboxylic acid copolymer may be in a matrix having a drug or in a primer or in a diffusion barrier.
One embodiment of the present invention includes a drug delivery coating. The drug delivery coating comprises a matrix comprising one or more co-polymers of ethylene comprising the reaction products of carboxylic acid containing unsaturated monomers. The drug delivery coating also includes a drug contacting the matrix. The drug delivery coating has a strong adhesion due to Van der Waals interaction resulting from carboxylic acid bonding of the coating to the material being coated.
One other embodiment of the present invention includes a stent. The stent comprises a tubular main body. The stent also comprises a coating that is adhered to the tubular main body. The coating comprises one or more co-polymers of ethylene wherein the co-polymers include a carboxylic acid moiety. The carboxylic acid moiety comprises one or more of acrylic acid, methacrylic acid, maleic acid, itaconic acid and all combinations and esters of these monomers. The coating deforms to a degree that accommodates stent deformation and, as a result, is resistant to cracking and delamination. The coating adheres to stents comprised of materials such as stainless steel.
Another embodiment of the present invention includes a drug delivery system. The drug delivery system comprises a tubular main body and a first coating that overlays the tubular main body. A drug is incorporated into the first coating. A coating comprising one or more co-polymers of ethylene with a carboxylic acid moiety overlays the first coating. The carboxylic acid moiety is one or more of acrylic acid, methacrylic acid, maleic acid, itaconic acid and all combinations and esters of these monomers. For some embodiments, the first coating is biodegradable.
Another embodiment of the present invention includes a method for improving manufacturability of a drug delivery system used with a medical device. The method comprises providing a medical device with a main body and providing a coating comprising cross-linkable co-polymers of ethylene with carboxylic acid. The method also includes applying the coating to the main body of the medical device.
The drug delivery coating of the present invention adheres to a metal substrate and has an elongation comparable to a metal or polymeric substrate. The drug delivery coating is soluble in a ternary blend. The ternary blend eases application of the coating to a medical device surface, such as a stent. The ternary blend also improves manufacturability as compared to polymeric drug delivery systems not using the ternary blend.
DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a perspective view of one embodiment of the stent of the present invention.
FIG. 2 illustrates a cross-sectional view of one embodiment of the drug delivery matrix of the present invention, wherein a drug is positioned within a polymeric matrix.
FIG. 3 a illustrates a cross-sectional view of another embodiment of the drug delivery matrix of the present invention wherein a polymeric matrix overlays a drug-containing matrix.
FIG. 3 b illustrates a cross-sectional view of another embodiment of the drug delivery matrix of the present invention wherein the polymeric matrix overlays the drug-containing matrix.
DETAILED DESCRIPTION
One embodiment of the present invention comprises an array of matrix drug delivery coatings 42 usable as drug delivery coatings for stents 40 , namely metal stents and polymeric stents, such as are illustrated, in one embodiment, in FIG. 1 . While a roll is shown in FIG. 1, it is understood that the coating may be a sheath or a thin coat for other implant embodiments. The array of matrix coatings comprises one or more cross-linkable co-polymers of ethylene, —(C 2 H 4 )— that comprises one or more carboxylic acid moieties. The carboxylic acid moieties are, for some embodiments, unsaturated monomers or unsaturated co-monomers. The unsaturated monomers or co-monomers are one or more of acrylic acid, methacrylic acid, maleic acid, itaconic acid and all combinations and esters of these monomers.
The carboxylic acid co-monomer content is at least about 5% by weight and not more than about 50% by weight of the polymer. The carboxylic co-monomer content is, for some embodiments, in a range of about 15 to 40% by weight of the polymer. The acid groups are, for some embodiments, partially neutralized. For other embodiments, the acid groups are fully neutralized using sodium hydroxide, potassium hydroxide, ammonia, and the like.
The term “ionomers” as used herein refers to polymers with acid groups that are neutralized with metal cations.
The term “matrix polymer” as used herein refers to a polymer capable of forming a coating on a surface of a medical apparatus and providing a network for containing a drug. The matrix polymer has functional moieties capable of crosslinking by hydrogen bonds to other moieties within the matrix polymer and crosslinking to any other moieties derived from the medical apparatus to enhance the strength and toughness of the coating. Adhesion is enhanced by Van der Waals interaction resulting from carboxylic acid bonding of the coating to the medical apparatus.
The term “elongation” as used herein refers to a percent elongation to break or an amount of strain the polymer can endure before rupturing.
Another embodiment of the present invention includes the matrix drug delivery coating of the present invention and a drug. For some embodiments, such as is illustrated at 20 in FIG. 2, the polymer comprising the coating acts as a drug eluting matrix. The drug 22 is incorporated within the drug eluting matrix 24 . For some embodiments, the drug is a particulate which is dispersed within the drug eluting matrix 24 . For other embodiments, the drug is dissolved within the matrix 24 .
The drug delivery coating acts as a barrier to rapid diffusion of the drug through the coating and to a treatment site. The drug delivery coating has a thickness ranging from about 0.1 to 3.0 mils, when applied to a stent. Because diffusion and drug release are delayed by the coating, the coating is usable for releasing drugs to a treatment site after a time interval of no or negligible drug release.
The coating of the present invention is usable with multiple drug delivery matrices in order to orchestrate drug release. In one embodiment, the coating, as shown in cross-section in FIG. 2, overlays a surface 26 , such as a stent surface. With this embodiment, the coating functions as a drug release coating. For another embodiment which is not shown, the coating is drug free and does not function as a drug release coating.
For some embodiments, the coating made with co-polymers of ethylene is a primer layer or a diffusion barrier. As a primer layer, the coating adheres to the surface of a stent. The primer layer also has functional moieties for crosslinking to a matrix polymer. For some embodiments, the primer layer is a dispersion of ethylene acrylic acid (EAA), such as Primacor 5980, available from Dow-Corning Corp. in Midland, Mich. or MICHEMPRIME 4983R, available from Michelman of Cincinnati, Ohio, or which is a dispersion that is capable of providing carboxyl moieties to the surface. As a primer layer, the coating of the present invention deforms to a degree that accommodates stent deformation, such as stent strut deformation. As a result, the coating is resistant to cracking and delamination and provides both elongation and high adhesion. For some embodiments, a drug is incorporated in the primer or the diffusion barrier. Typically, the drug concentration for these embodiments is lower if the matrix layer is present.
Thus, the coating of the present invention accomplishes what many other polymers cannot perform. Thermosets such as epoxies, polyesters, phenolics, polyimide, as well as conventional thermoplastics such as vinyl chloride, cellulosics, styrene, methyl methacrylate and thermoplastics such as PEEK, PPS, polysulfone, polycarbonate, Mylar, unless the strain occurs above the polymer's glass transition temperature, do not elongate and adhere to a degree that makes them acceptable coatings for stent devices.
For other embodiments, the polymer comprising the coating is positioned to provide a diffusion limiting barrier for a drug reservoir, such as a micro-depot 17 , shown in FIG. 3 a . The micro-depot 17 is defined by a divot formed at the surface 14 of the stent 13 . This embodiment is illustrated generally at 10 in FIG. 3 a . A coating illustrated at 12 overlays a stent surface 14 . For some embodiments, the coating 12 includes drugs and for other embodiments, the coating 12 is drug-free. The polymer overcoat 16 of the present invention overlays the coating 12 . The coating matrix includes one or more of poly(ethylene-acrylic acid), EAA, poly(ethylene-vinyl alcohol), poly(ethylene vinyl acetate), poly n-butyl methacrylate, poly(ethylene oxide) or a polyurethane elastomer such as Bionate 80A, manufactured by Polymer Technology Group of Berkeley, Calif. Bionate 80 is a polycarbonate-urethane and is a thermoplastic elastomer formed as a reaction product of a hydroxyl terminated polycarbonate, an aromatic diisocyanate, and a low molecular weight glycol which is used as a chain extender. The overcoat 16 includes one or more of EAA, ethylene-methacrylic acid (EMAA), and other ethylene, acrylic acid-based materials.
For other embodiments such as is illustrated at 30 in FIG. 3 b , the polymer overcoat 16 functions as a cover over a drug-only layer 32 or a drug/non-drug mixture layer, which is not shown. The coat may be biodegradable but there may be non-biodegradable coats, as well. One layer of this type is a layer that comprises a drug and a biodegradable material such as phosphatidylcholine. Other suitable biodegradable materials include linear aliphatic polyesters like polyglycolide and polylactide from poly(alpha-hydroxyacetic acids), poly(orthoesters), polyanhydrides, polysaccharides, poly(ester amides), tyrosine-based polyarylates or polyiminocarbonates or polycarbonates, poly(D,L-lactide-urethane), poly(beta-hydroxybutyrate), poly(e-caprolactone), poly[bis(carboxylatophenoxy)phosphazene], poly(amino acids), pseudo-poly(amino acids), and copolymers derived from amino acids and non-amino acids. As the biodegradable layer degrades, the drug is released.
For other embodiments, the matrix polymer coats a medical device such as a stent as shown at 40 in FIG. 1 but the polymer acts as a primer, and is free of drugs. For these embodiments, the matrix polymer 42 coats surfaces that are regarded as difficult to coat, such as stainless steel. Stainless steel is regarded as a difficult to coat metal because stainless steel has an outer surface that is trivalent chromium oxide, which provides a less reactive surface than other metal oxides. It is the interactions between metal oxides on the substrate and functional groups on the polymer that provide the adhesive force.
For some embodiments, the polymer coating formulation of the present invention also includes one or more of a surfactant, a colorant, and one or more plasticizers or mixtures of these materials. Some of the co-polymer coating embodiments of the present invention comprise co-polymers that are soluble in ternary blends comprising toluene, a chlorinated solvent, and a lower alcohol. The ternary blends of toluene, chlorinated solvents, and lower alcohols, are usable to dissolve and to apply the polymer or polymer/drug blend to a stent. For example, a blend of 15% trichloroethane, 15% 2-propanol and 70% toluene is usable to dissolve a coating polymer manufactured by Dow Chemical, PRIMACOR 5980. For some embodiments, the polymer coating formulation is dissolved at an elevated temperature. The use of these ternary blends renders the coating application process easier in that a coating has a viscosity that eases application and uniformity of thickness.
Specifically, solvents dissolve the polymer to make a coating solution. Surfactants are added to improve substrate wetting. Surfactants are also added to prevent foaming. Plasticizers increase elongation at the expense of hardness and tensile strength.
The co-polymers are neutralized in a volatile or a non-volatile base. The copolymers are dispersed in water and in co-solvents such as the ternary blends that are described. Specifically, the co-solvents include the ternary blends of toluene, chlorinated solvents and lower alcohols.
In one particular example, a coating of the present invention is made with a PRIMACOR 5980I, which is manufactured by Dow Chemical of Midland, Mich. The PRIMACOR 5980I is an ethylene acrylic acid copolymer, EAA, that adheres to metals and other polar substrates. The PRIMACOR 5980I has the physical properties described in Table 1.
TABLE 1
Physical Properties
Test Method
Values (SI)
Resin Properties
Weight Percent Comonomer
Dow Method
20.5
Melt Index, g/10 min
ASTM D 1238
300
Melt Flow Rate, g/10 min
ASTM D 1238
13.8
Density, g/cc
ASTM D 792
0.958
DSC Melting Point, F (C)
Dow Method
171 (77)
Vicat Softening Point, F (C)
ASTM D 1525
108 (42)
Molded Part Properties
Ultimate Tensile, psi (Mpa)
ASTM D 638
1400 (10)
Ultimate Elongation, %
ASTM D 638
390
Tensile Modulus, 2% secant, psi (MPa)
ASTM D 638
4800 (33)
Hardness, Shore D
ASTM D 2240
50
One other polymer formulation usable in the coating formulation of the present invention is provided in an ammonia neutralized aqueous dispersion at 25% solids, manufactured by Michelman Inc. The product name is Michem Prime4983 R. The Michem Prime 4983R product includes EAA solids in a percent of 25% non-volatiles. Dow Primacor 5980i is also usable. The specific gravity is 0.98 to 1.00. The particle size is about 0.03 micron. The viscosity is about 50 to 400, as measured with a No. 2 spindle. The hardness, as measured by ASTM test D-5, is about 54 sd.
This Michem Prime 4983R dispersion is, for some embodiments, blended in a concentration that is less than 40% w/w, and is preferably within a range of 5 to 20% w/w with a co-solvent and, optionally, with a drug component. This dispersion is applied by standard coating application techniques such as spray coating or dipping, at substantially room temperature. When used as a primer, an addition of about 20 to 50 micrograms of coating material per stent is typically used. As a matrix with drug, about 50 to 500 micrograms per stent are applied to each stent. If used as a diffusion limiting barrier coat, a quantity of about 50 to 500 micrograms of material are applied to each stent. Once the coating is applied to a stent, the coating and stent are baked at low temperature, 120 degrees to 150 degrees F., for a period of time that is sufficient to drive off the solvents and any volatile amine. Coating and heating produces a conformal coating on the device. For some embodiments, the coating is dried at room temperature, rather than being subjected to baking.
Another embodiment of the present invention includes a stent or other implantable medical device made with the coating of the present invention. The medical device comprises a main body comprising a material such as stainless steel, nickel, gold, chrome, nickel titanium alloy, platinum, other metals, silicone, polyethylene, other polyolefins, polyesters, other plastics, glass, polyurethane, acetal, polyamide, and polyvinyl chloride. Medical devices include catheters, microcatheters, wires, wound drains and dressings, arteriovenous shunts, gastroenteric tubes, urethral inserts, laparoscopic equipment, pellets and implants. The medical devices are made for some embodiments with coating alone. For other embodiments, the medical devices deliver drugs through the drug delivery coating.
The drug delivery coating of the present invention substantially eliminates problems of marginal substrate adhesion, insufficient elongation resulting in cracks and limited and sub-optimal solvent choices resulting in difficult application and poor manufacturability. The carboxylic acid groups of the ethylene polymer impart a high adhesion to the coating so that the coating strongly adheres to metal. The ethylene content insures sufficient elongation of the coating to accommodate the strain associated with stent expansion.
An ability to neutralize the acid groups with a volatile or permanent counter ion provides water dispersibility properties to the coating. The water dispersibility is compatible with organic co-solvents such as 2-propanol or methyl ethyl ketone to aid in substrate wetting and improved application properties. The acid groups that are not ionically neutralized in the dried film are usable to associate with amine groups on a drug, such as Actinomycin D, and to retard its release.
Thus, the drug delivery coating of the present invention resists wet abrasion. The coating remains coherent without cracks despite flexing when applied to substantially inert surfaces that are difficult to coat, such as stainless steel. This performance is an improvement over other coatings which do not display optimal properties when applied to stainless steel.
Due to a high ethylene content, the hydrophobic nature of the dry film retards the transport of drug molecules, which tend to be functionalized and have some hydrophilic character.
Examples of such active ingredients include antiproliferative substances as well as antineoplastic, anti-inflammatory, antiplatelet, anticoagulant, antifibrin, antithrombin, antimitotic, antibiotic, antioxidant, and combinations thereof. A suitable example of an antiproliferative substance includes actinomycin D, or derivatives and analogs thereof (manufactured by Sigma-Aldrich 1001 West Saint Paul Avenue, Milwaukee, Wis. 53233; or COSMEGEN available from Merck). Synonyms of actinomycin D include actinomycin, actinomycin IV, actinomycin I1, actinomycin X1, and actinomycin C1. Examples of suitable antineoplastics include paclitaxel and docetaxel. Examples of suitable antiplatelets, anticoagulants, antifibrins, and antithrombins include sodium heparin, low molecular weight heparin, hirudin, argatroban, forskolin, vapiprost, prostacyclin and prostacyclin analogs, dextran, D-phe-pro-arg-chloro-methylketone (synthetic antithrombin), dipyridamole, glycoprotein IIb/IIIa platelet membrane receptor antagonist, recombinant hirudin, thrombin inhibitor (available from Biogen), and 7E-3B® (an antiplatelet drug from Centocore). Examples of suitable antimitotic agents include methotrexate, azathioprine, vincristine, vinblastine, fluorouracil, adriamycin, and mutamycin. Examples of suitable cytostatic or antiproliferative agents include angiopeptin (a somatostatin analog from Ibsen), angiotensin converting enzyme inhibitors such as CAPTOPRIL (available from Squibb), CILAZAPRIL (available from Hoffman-LaRoche), or LISINOPRIL (available from Merck); calcium channel blockers (such as Nifedipine), colchicine, fibroblast growth factor (FGF) antagonists, fish oil (omega 3-fatty acid), histamine antagonist, LOVASTATIN (an inhibitor of HMG-CoA reductase, a cholesterol lowering drug from Merck), monoclonal antibodies (such as PDGF receptors), nitroprusside, phosphodiesterase inhibitors, prostaglandin inhibitor (available form Glazo), Seramin (a PDGF antagonist), serotonin blockers, steroids, thioprotease inhibitors, triazolopyrimidine (a PDGF antagonist), and nitric oxide. Other therapeutic substances or agents which may be appropriate include alpha-interferon, genetically engineered epithelial cells, and dexamethasone.
While the foregoing therapeutic agents have been used to prevent or treat restenosis, the drugs are provided by way of example and are not meant to be limiting, since other therapeutic drugs may be developed which are equally applicable for use in the present invention. The treatment of diseases using the therapeutic agents described as well as dosage rates are known.
For some embodiments, a selected drug is intimately mixed with the polymeric coating material of the present invention in order to uniformly disperse the therapeutic drug in the polymeric material. For other embodiments, the drug is incorporated into a matrix such as a biodegradable polymer matrix. The specific method of uniformly dispersing the therapeutic drug in the polymer is variable, and depends upon the stability of the therapeutic drug to thermal processing. Ethylene and acrylic acid, for example, are co-polymerized by free radical techniques to form an essentially linear polymer. However, ethylene is not “crosslinked” by the acid co-polymer. The acid groups randomly placed along the chain hydrogen bond to each other. The acid groups crosslink each other, not the ethylene groups.
For some embodiments, the therapeutic drug is uniformly dispersed in the polymeric material by coextruding small solid particles of the drug with the polymer material. The specific method of uniformly dispersing the therapeutic drug in the polymer varies and depends upon the stability of the therapeutic drug to thermal processing. The therapeutic drug is uniformly dispersed in the polymeric material by coextruding small solid particles of the selected therapeutic drug with the selected polymeric material. This extrusion device includes a hopper into which the polymeric material and small particles of selected therapeutic drug are added together, and into which a porosigen is also added, if desired. The extruder also typically includes a lead screw that drives and that intimately mixes the ingredients together, to uniformly disperse the small particles of the therapeutic drug, and if desired, a porosigen as well, in the polymeric material.
The barrel of the extruder is heated by temperature controlled heaters surrounding the barrel in stagers. A motor and associated gears are provided to drive the lead screw, and a cooling system is also typically provided. This method of intimately mixing the therapeutic drug and polymeric material yields a relatively high and uniformly distributed loading of the therapeutic drug in the polymer. While a loading of the therapeutic drug is currently no more than about 40% by weight, depending upon the specific application and interaction of the polymer with the drug, drug loadings as high as 70% by weight have been achieved by this method. A preferable concentration range is 5 to 20% by weight. The drug loaded polymer is extrudible into an appropriate shape, or can be subsequently calendered to produce a drug loaded polymer film having a smooth surface, with the therapeutic drug uniformly distributed in the film.
A polycarbonate-urethane material such as Bionate 80 is very hygroscopic. Pellets of Bionate 80 are dried by a process such as forced air dehumidifying dryer at 82 degrees C. for at least about 4 hours prior to extrusion or injection molding. Bionate 80 pellets are typically filtered during extrusion, through filters such as a 350 mesh filter and two 500 mesh filters.
Extrusion equipment is set with a cross head temperature of about 200 degrees C. to 215 degrees C. to initiate the flow. Once flow is established, the cross head temperature is decreased until steady, viscous flow is achieved. Extrusion conditions for the polycarbonate-urethane material are typically within the following ranges:
Conditions
Temperature (C)
Temperature (F)
Barrel-Zone 1
200-215
390-420
Barrel-Zone 2
193-230
380-445
Barrel-Zone 3
193-230
380-445
Die
200-215
390-420
Melt Temperature
191-221
375-430
Extruder Configuration
Parameter
Value
Length to Diameter Ratio
24:1
Compression Ratio
2.5:1 to 3.5:1
Cooling Water Temperature
18-20 degrees C.
The particles of the desired therapeutic drug are formed to have a maximum cross-sectional dimension of about 10 microns. An average particle size of less than 10 microns and a uniform distribution of the particles of the therapeutic drug in the polymeric material provide a therapeutically effective amount of the therapeutic drug in the layer of the polymeric material to be applied to the structure of the stent, since the layer of polymeric material typically is as thin as 25 microns. The size and distribution of the particles of the therapeutic drug affect the physical properties of the polymer.
In other embodiments, the therapeutic drug is compounded with the polymer by calendering the ingredients, such as in a two roll mill, for example. This method yields a relatively high and uniformly distributed loading of the therapeutic drug in the polymer.
The matrix coating is applicable to the surface of a stent using methods such as dipping, spraying, flowing, rolling and brushing. Thickness of the coating ranges from about 0.1 to about 3 mils. The thickness is adjustable by adjusting viscosity of the coating material prior to application. Thickness is also adjustable by applying multiple coating layers.
The embodiments illustrated and discussed in this specification are intended only to teach those skilled in the art the best way known to the inventors to make and use the invention. Nothing in this specification should be considered as limiting the scope of the present invention. Modifications and variations of the above-described embodiments of the invention are possible without departing from the invention, as appreciated by those skilled in the art in light of the above teachings. It is therefore to be understood that, within the scope of the claims and their equivalents, the invention may be practiced otherwise than as specifically described. | A coated stent is provided including a coating comprising one or more co-polymers of ethylene with carboxylic acid wherein the carboxylic acid co-monomer content is 5-50 wt%. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Priority is claimed to U.S. Provisional Application Ser. No. 60/552,577 filed Mar. 12, 2004 and U.S. Provisional Application Ser. No. 60/562,683 filed Apr. 15, 2004.
BACKGROUND OF THE INVENTION
[0002] This invention is generally in the field of ocular lubricants, and in particular relates to a formulation for treatment of the symptoms of dry eye.
[0003] The surface of the eye requires constant lubrication for proper function. This includes quality of vision as well as comfort. The eye becomes irritated and vision blurs when inadequately lubricated. This condition is frequently referred to as dry eye. Inadequately treated severe dry eye can lead to cornea scarring, blindness and even loss of the eye. Dry eye is a common condition and many over-the-counter and even prescription therapies are available to mitigate this at times difficult and annoying condition. Many patients are unable to find relief with present therapies.
[0004] It is well recognized that the meibomian gland secretions of the eyelid provide the lipid layer of the tear film. The major component of the meibomian gland lipid secretions are wax esters (Driver and Lemp, Meibomian Gland Dysfunction, Surv Ophthalmol 40:343-367, 1996). It is also known that the natural product jojoba is comprised of over 97% wax esters of the long chain variety similar to that of the lipid tear film.
[0005] It is therefore an object of the present invention to provide a formulation for alleviating the symptoms of dry eye.
[0006] It is a further object of the present invention to provide an over the counter formulation for alleviating the symptoms of dry eye.
SUMMARY OF THE INVENTION
[0007] A formulation has been developed for treatment of the symptoms of dry eye which incorporates the natural product jojoba wax, or components thereof, to enhance the spreading of the artificial tear as well as stabilize the tear film. The jojoba wax tear relieves irritation and discomfort as well as sharpens the blurred vision.
DETAILED DESCRIPTION OF THE INVENTION
[0008] A jojoba liquid wax formulation providing comfort and clarity of vision to patients with dry eye has been developed. The wax esters of the jojoba improve and enhance the spreading, stability and lubricating effect of the artificial tear on the tear film.
[0000] I. Formulation
[0009] A. Wax
[0010] In the preferred embodiment, the formulation contains jojoba wax in an emulsion. The jojoba wax performs as lubricant and evaporation retardant for the tear film. Jojoba wax is a liquid wax composed of long chain wax esters.
[0011] The components of the jojoba wax esters include long chain alcohols esterified with long chain fatty acids with a total of 38 to 44 carbon atoms. Exemplary long chain fatty acids include gadoleic, palmitic, palmitoleic, stearic, oleic, linoleic, arachidic, linolenic, eicosenoic, behenic, erucic, lignoceric, lactic, decate, acetic and myristic fatty acids. The fatty acids typically have carbon chains of C12 to C30, with or without various degrees of saturation or unsaturation. The alcohol components of the wax ester contain carbon chains between C16 and C32 with or without various degrees of saturation or unsaturation. The alcohol component may be eicos-11-enol, docos-13-enol, tetracos-15-enol, myristyl alcohol, octyldodecyl stearoyl alcohol or cetyl alcohol.
[0012] Jojoba's melting point is about 6° C. It is extracted from seeds and leaves of the jojoba tree ( Simmondsia chinensis ) cultivated in the desert conditions of Arizona and California as well as Northern Mexico and other locations. The chemical structure does not vary with plant type, growing location, soil type, rainfall or altitude. The oil produced by jojoba lacks triglycerides. It does not contain glycerol combined with fatty acids. Rather the jojoba combines fatty alcohols with fatty acids to produce a vegetable oil which is actually a liquid wax, having its own type of molecular size and shape with unusual anti-evaporative properties which protect the shrub from its severe arid natural habitat. Jojoba wax or the wax esters therein keep the shrub well lubricated and moisturized yet it is non occlusive. The non-occlusive property is related to its porosity. In the shrubs and trees it is derived from, the porosity allows for evaporative exchange of vapors thus cooling the jojoba tree in its hot native climate.
[0013] The natural jojoba is 97% wax esters with few impurities. There are no resins, tars, or alkaloids and only a trace amount of saturated wax, alcohols, fatty acids, and hydrocarbons. Jojoba wax is non toxic and biodegradable and is pasteurized to kill microorganisms (National Research Council. 1985. Jojoba: New Crop for Arid Lands, New Material for Industry . National Academy Press, Washington, D.C.). The liquid wax commercially available does not include those solid components of the seed which have toxic effects; the glycosides simmondsin and simmondsin-2-ferulate.
[0014] The wax esters are comprised of alcohols esterified with long chain fatty acids with a total of 38 to 44 carbon atoms. The fatty alcohols are predominantly 20 and 22 carbon atoms with one double bond. Its fatty acids are mostly 20:1 (70%), with some 22:1 (20%) and the remainder 18:1 (10%). All double bonds have a cis configuration and are spaced widely apart equidistant from the ester linkage creating an especially stable molecule resistant to oxidation. The cis double bond configuration is also felt to give the jojoba its porosity.
[0015] Oils having similar properties to jojoba wax, or its components, may be substituted for the jojoba oil. Jojoba has been identified as chemically similar to sperm whale oil, an unsaturated wax. Sperm whales were sought for their oil throughout the 20 th century since it is considered a fine lubricant oil. Due to the near extinction of the sperm whale, alternative lubricants were sought. Although jojoba was known to similar to sperm whale oil since the 1930's, the advanced study of its chemistry was not available until the 1970's and 1980's due to advances in technology. Both are fine lubricants as they are stable at high temperatures and high pressures. However, jojoba is now felt to be a superior lubricant to sperm whale oil (National Academy of Sciences. 1975. Products from Jojoba: A Promising New Crop for Arid Lands . National Research Council Washington D.C.). Another similar oil to sperm whale oil is from the fish Orange Roughy. This oil and other fish oils may be used in place of or in combination with the jojoba.
[0016] Jojoba wax is approved by the Food and Drug Administration (“FDA”) for use in cosmetics and other formulations for application around the eyes, although not for direct application to the eye. Jojoba wax is used extensively in the cosmetic industry in up to at least a 10% in water emulsion, in eye makeup remover, as well as for skin and hair products. It is also used in therapeutic massage. Primary eye irritation studies have been performed in rabbits using undiluted refined jojoba liquid wax. Slight irritation was noted which resolved within 24 hours. A 20% natural jojoba wax dropped in rabbit eyes was concluded a nonirritant (Final Report on the Safety Assessment of Jojoba Oil and Jojoba Wax, J Amer College Toxicology, 11 (1), 1992, 57-74.) The Environmental Protection Agency (EPA) in the Federal Register 40 CFR Part 180, 1995 acknowledged the wide distribution of Jojoba in commerce and availability to the general public throughout the United States without any evidence of significant adverse effects to humans or the environment. The Cosmetic Ingredient Review lists Jojoba as safe to use.
[0017] Jojoba wax has also been shown to help break down sebum in plugged up sebaceous pores of the skin. It may prove to also be able to break down and unplug the modified sebaceous (meibomian) glands of the lid when applied as a drop or an ointment or other topical therapy.
[0018] Jojoba wax also has intrinsic antimicrobial properties which include activity against envelope viruses, mold, fungus and bacteria. U.S. Pat. Nos. 4,585,656 and 6,559,182 describe the efficacy of treating envelope viruses with jojoba wax esters. In vitro experiments in the literature showed jojoba has an intense inhibiting effect on Mycobacterium tubercle bacilli. It may be useful as a prophylactic as well as therapeutic agent to prevent and treat ocular or periocular infections. It may be used as therapy for infection of any part of the eye or adnexal structure.
[0019] Other jojoba derivatives which may be incorporated into an ophthalmic delivery system include jojoba esters, jojoba alcohols, and the hydrogenated jojoba solid wax. Jojoba esters are the result of an inter-esterification of various ratios of jojoba liquid wax and hydrogenated jojoba solid wax. The physical consistency ranges from liquid to semi-solid paste or creams. Jojoba solid wax is derived from the hydrogenation and complete reduction of the unsaturated wax esters. It is a hard crystalline wax comparable to beeswax with a melting point of 69° C. and can be prepared in a wax in water emulsion. This wax-in-water emulsion emulsifies easily and may also be used in an ophthalmic preparation. Possible emulsifying agents for the ophthalmic preparation include stearic acid (4%) and triethanolamine (2%). Jojoba alcohols are generated from a sodium reduction of jojoba liquid wax and hydrogenated jojoba solid wax with subsequent additional refinement. Jojobutter-51 is an isomorphous mixture of jojoba liquid wax, partially isomerized jojoba liquid wax and hydrogenated jojoba solid wax (J Amer College Toxicology, 11 (1), 1992). Sulfurization of jojoba results in enhanced lubricant properties which is further enhanced with phosphorus, bromine or chlorine. (Wisniak J The Chemistry and Technology of Jojoba Oil, Am Oil Chemist Society, 1987) and may optimize the lubrication of an ophthalmic tear supplement.
[0020] B. Artificial Tears
[0021] The wax is mixed with an aqueous solution for application to the eye. Typically the aqueous solution may be sterile water or hypotonic or isotonic saline and will contain buffer to physiological pH, in the range of about 7-7.5. It may also be cell culture media such as Dulbecco's Media (DMEM). It will also contain a surfactant/lubricant/demulcent such as polysorbate 80. Ancillary ingredients to establish the desired tonicity with tears may include electrolytes. Preservatives such as sodium bisulfite, ascorbic acid, alpha-tocopherol, benzalkonium chloride, ethylenediaminetetraacetic acid (EDTA) and chlorhexidine can be used as well as chlorbutanol, sodium perborate and stabilized oxy-chloro complex. Other preservatives include polyquad, polyhexamethyl biguanide, chlorhexidine, propylparabens and methylparabens and others. Other additives may include humectants such as propylene glycol and sorbitol. Representative pH buffers include sodium borate or mono and di-sodium phosphate or other phosphate, carbonate or acetate salts.
[0022] The jojoba wax concentration in an aqueous carrier will typically be between 0.001% to 50%. The jojoba in aqueous emulsion may include a second emollient such as mineral or light mineral oil. Other emollients may be used in the emulsion such as white petrolatum, white ointment, paraffin, and beeswax or other wax. These emollients may be used to increase the viscosity of the emulsion. The ratio of jojoba to the second emollient is from greater than 1:5 to 500:1. Jojoba is also available as a clear, water colored refined liquid wax which may also be used as a second emollient in the above ratios.
[0023] The formulation may further include a sterol, hydroxycarotenoid or Vitamin A optionally esterified with fatty acids of various chain lengths between C10 and C30. The formulation may also include polar lipids including glycolipids, sphingolipids and/or phospholipids including phosphatidylinositol, phosphatidylethanolamine, sphingomyelin, phosphatidylglycerol, and diphosphatidylglycerol, Triglycerides may also be included.
[0024] Suitable lubricants used with the wax ester in a concentration between 0.01% to 20% include cellulose derivatives. Examples of cellulose derivatives include carboxymethylcellulose sodium 0.2 to 2.5%, hydroxyethyl cellulose 0.2% to 2.5%, hydroxypropyl methylcellulose 0.2% to 2.5%, and methylcellulose 0.2% to 2.5%. Other examples of lubricants include Dextran 70, (0.1%), gelatin, 0.01%, glycerin, 0.2 to 1%, polyethylene glycol 300, 0.2 to 1%, polyethylene glycol 400, 0.2 to 1%, polysorbate 80, 0.2 to 5%, propylene glycol, 0.2 to 5%, polyvinyl alcohol 0.1 to 5%, and povidone 0.1 to 5%. These lubricants can increase viscosity of the artificial tear as a mucomimetic and may be added to the formulation. The formulation can be thought of as a tear replacement therapy. Additional mucomimetics include carbomer and hyaluronic acid.
[0025] Ophthalmic astringents may also be included. One example is zinc sulfate, 0.25%. A hypertonicity agent may be used such as sodium chloride 2 to 5%. An ophthalmic vasoconstrictor may be used including ephedrine hydrochloride, 0.123%, naphazoline hydrochloride, 0.01 to 0.03%, phenylephrine hydrochloride, 0.08 to 0.2% and tetrahydrozoline hydrochloride, 0.01 to 0.05%.
[0026] The eye drop can also include a further emulsifier.
[0027] Proteins normally found in the tear may be included in the formulation to further increase stability. These may include amongst others, prealbumin, albumin, lyzozyme, lactoferrin, beta lactoglobulin, IgA as well as lipocalins.
[0028] Suitable electrolytes include sodium chloride, potassium chloride, sodium phosphate, potassium phosphate, sodium and potassium sulfates and sodium and potassium bicarbonates. Suitable non electrolytes such as glycerin and sugars such as urea, sorbitol, glucose and sucrose can also be added.
[0029] In another embodiment, the jojoba wax, up to 70%, is formulated as an ointment emollient. A suitable carrier includes a mixture of mineral oil and petrolatum in a ratio of about 70% to 30%, paraffin up to 5%, white ointment up to 100%, white petrolatum up to 100%, petrolatum up to 100%, white wax up to 5%, yellow wax up to 5%, colorless jojoba wax up to 50%, lanolin 1 to 10% and anhydrous lanolin 1 to 10%.
[0030] The formulation can also be used as a platform to deliver other active agents. Other active ingredients that could be used include anti-glaucoma therapies, antibiotics, antimicrobial peptides, antivirals, antiparasitics, antifungals, antiinflammatories, antihistamines, anti-allergy therapies, hormones such as androgens and others, vitamins, growth factors, cytokines, mucins, surface stimulating drugs, immunomodulators, immune response modifiers, cytokine modifying agents, immunosuppressive agents, antineoplastic agents, eyelash growth stimulators and other medicaments.
[0031] Additional classes of additives include lubricants, preservatives, stabilizers, wetting agents, emulsifiers, buffers, and different salts to alter osmotic pressure, as well as solubilizing agents, dispersants, and detergents.
[0032] The wax can also be added to artificial tears obtained over the counter (“OTC”). Examples include VISINE™ marketed by Pfizer, REFRESH TEARS™ product line marketed by Allergan, SYSTANE™ marketed by Alcon, GENTEAL™ marketed by Novartis, and OCUCOAT™ marketed by Bausch and Lomb.
[0000] II. Methods of Use
[0033] In the preferred embodiment, the formulation is administered once to four times a day directly to the eyes of the individual in need thereof. The frequency will vary depending on the severity of symptoms. The formulation may be applied as a drop in the form of an emulsion or suspension, liposome, lotion, ointment, cream, gel, salve or powder and sustained or slow release, as well as eyelid lotion. It may also be used as an eye wash or rinse to irrigate the eye. The formulation may also be applied in a sprayable form. This lubricant will be extremely helpful in eradicating the symptoms of dry eye in the various settings it occurs. This includes the most common settings of age related so called dry eye syndrome, computer related dry eye, dry eye after Lasik, and dry eye associated with reading, driving or watching a movie or television. Patients with contact lens intolerance or who use an ocular prosthesis will also greatly benefit from the enhanced lubrication. Other examples include patients with a history of eye surgery and dry eye. This includes cataract surgery, cornea surgery and cornea transplants. Patients with neurologic disorders such as Bell's Palsy or other neuroparalytic as well as neurotrophic disease will also benefit. Lagophthalmous characterized by an exposed ocular surface which can occur while sleeping or even during waking hours will be improved with the ointment, and/or gel form of this lubricant. Devastating although rare mucous membrane blistering diseases as Stevens Johnson Syndrome are also associated with both a watery and lipid dry eye due to fibrotic changes associated with glandular tissues. The jojoba formulation should be especially helpful to replace lipid and aqueous deficiencies and help relieve suffering to comfort an otherwise extremely painful eye.
[0034] Other types of dry eye characterized by plugged, inflamed and/or dysfunctional sebaceous glands of the lid known as meibomian gland dysfunction should also be mproved with use of this formulation applied to the eyelids.
[0035] Patients with eye infections of the lid, conjunctiva, cornea and tear apparatus and lacrimal gland should also benefit with application of this formulation in one or more forms to the eyelids, conjunctiva, and cornea as well as tear film and other adnexal structures including lacrimal gland, and tear outflow system including puncta, canaliculi, and lacrimal sac.
[0036] In preliminary studies on skin, Jojoba wax has been shown to relieve pain and reduce swelling from superficial thermal and chemical burns. There may also be a therapeutic effect on ocular burns.
[0037] The formulation can also be used to prevent, treat or alleviate the symptoms of envelope viruses including herpes simplex keratitis, and varicella zoster keratitis which causes chicken pox and shingles. Other viral infections of the eye that may be treated include human herpes virus 8 (HSV 8), Kaposi sarcoma as well as Epstein-Barr virus, cytomegalic inclusion virus (CMV) and Human Immunodeficiency Virus (HIV).
[0038] Non-ocular uses of the formulation include use to treat or prevent accumulation of ear canal wax, treatment of vaginal dryness or other symptoms of perimenopausal dryness, moisturizing dry nasal mucosa or where the patient has a sinus condition, including inflammation or infection.
EXAMPLES
[0039] In a preferred embodiment, the formulation contains 0.5-5% jojoba wax, most preferably 0.5 to 2% jojoba, 1% polysorbate 80 in a aqueous buffered saline based liquid wax emulsion.
[0040] The 2% jojoba formulation was administered to a total of 16 volunteer individuals with different types of irritated eyes. The drop was reported to be extremely comfortable for all individuals without causing visual blur.
[0041] Three volunteers had painful dry eye after Lasik. None of the conventional therapies had helped them thus far. For PC, AS, and KA, relief was immediate and lasted about 8-10 hours.
[0042] For TB who said his irritation was allergic in nature, none of the presently available OTC drops had helped relieve his severe symptoms. One drop of the jojoba wax formulation applied to each eye relieved all symptoms for the entire day.
[0043] For JR who said his eyes are always irritated in the morning, get red and stay red for hours and who has yet to find a comfortable and effective OTC eyedrop, one drop of the jojoba wax formulation applied to each eye eliminated the red eyes and comforted his eyes for the entire day.
[0044] Two individuals (RD and AM) used the jojoba wax formulation in the setting of soft contact lens wear and found its comforting properties to be truly unique. They enjoyed instant relief of eye discomfort which lasted the entire day.
[0045] One individual (ST) used the jojoba wax formulation in the setting of rigid contact lens wear and also had instant relief of eye irritation lasting the whole day.
[0046] In summary, the volunteers were extremely pleased by the comfort, immediate and lasting relief of the jojoba wax formulation.
[0047] Three additional patients (HK, LF, and IM) with cornea erosions were placed on this formulation using 1% jojoba wax. The drop was used four times per day. The drop was well tolerated, and was found to be soothing and very comfortable. Within one to two weeks the erosions were markedly and almost completely resolved.
[0048] A formulation consisting of 5% jojoba in aqueous with additional 0.05% white petrolatum USP was created using a heating stir plate and was placed in the right eye of 6 volunteers. For MB, MH, DN, HL, AM, and SM the drop was well tolerated, comfortable and felt thicker than 5% jojoba in aqueous emulsion without the petrolatum.
[0049] The formulation was also evaluated on two volunteers using lipid tear interferometry. A drop of the formulation was placed in one eye and an artificial aqueous tear in the other. The interferometry pattern showed thick blue waves of liquid wax quickly mixing with the volunteer's own lipid tear within seconds. The resultant lipid tear pattern showed a healthy enhanced film at least three hours later. Breakup times were also prolonged therapeutically in the eye receiving the emulsion compared to the fellow eye.
[0050] Modifications and variations of the present invention will be obvious to those skilled in the art from the foregoing detailed description and are intended to come within the scope of the following claims. All references herein are expressly incorporated by reference. | A formulation has been developed for treatment of the symptoms of dry eye which incorporates the natural product jojoba wax, or components thereof, to enhance the spreading of the artificial tear and eyedrop as well as stabilize the eyedrop. The improved performance of the jojoba wax supplemented tear relieves irritation and discomfort as well as sharpens the blurred vision. | 0 |
[0001] This application claims the priority to Chinese patent application No. 200820094651.1, filed with the Chinese State Intellectual Property Office on Jun. 16, 2008 and titled “Stamping Die”, which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to a stamping die and in particular to a stamping die with a storing position-limiting mechanism.
BACKGROUND OF THE INVENTION
[0003] With the development of the automotive industry, competitions are intensified. And raising efficiency and reducing costs have become an issue that requires automobile manufacturers' attention. As one of the four major manufacturing processes, stamping plays an important role in automobiles production. Reducing production costs of stamping pieces and reducing die changeover time in coachwork manufacturing are one of the key tasks.
[0004] Dies used in automated production lines are normally stored in stacks, and can be installed to a press through a die loading process. While they are in storage, a position-limiting mechanism provided in the dies keeps elastic elements of the dies from being pushed and deformation.
[0005] Two conventional methods exist for position limiting of dies in storage. One uses solely a rigid storing limiter. In the die loading process, a slider of the press is adjusted by an operator according to a storing height of a die, so as to lock the die to the press; then, the rigid storing limiter is removed manually, and the slider is adjusted once again according to a working height of the die. This process requires a long die changeover time, and does not support automated die loading. Moreover, the operator has to enter the die working area, posing a serious risk to safety. The other method uses solely a nitrogen gas spring as an elastic storing limiter. This method may meet the requirement of automated die loading and save die loading time. However, when many dies are stacked, the nitrogen gas spring may be compressed too much, losing its function as a storing limiter and causing damages to elastic elements of the dies. Using a nitrogen gas spring with a higher stiffness may allow the stacking of dies, but may also raise costs of the dies significantly and cannot prevent potential gas leak and failure due to long working hours of the dies; hence it cannot prevent damages to elastic elements of the dies.
SUMMARY OF THE INVENTION
[0006] A technical problem to be solved by the invention is to cure the deficiencies in the prior art, and to provide a stamping die that supports automated die loading and can prevent elastic elements from being damaged when the dies are stored in stacks.
[0007] The technical problem of the invention is solved by the technical solution described as below.
[0008] A stamping die, includes: a lower die; a direction-guiding guide pillar, arranged on the lower die, an upper die, connected with the lower die via the guide pillar; a working position limiter; and a rigid storing limiter, arranged on the lower die. The stamping die further includes at least one elastic storing limiter arranged between the upper die and the lower die.
[0009] The elastic storing limiter may be a nitrogen gas spring.
[0010] The stamping die may further include an elastic position limiter cushion arranged between the nitrogen gas spring and the upper die.
[0011] A counterbore matching the nitrogen gas spring may be provided in a lower face of the elastic position limiter cushion that is in contact with the nitrogen gas spring.
[0012] An elastic position limiter cushion storing hole for containing the elastic position limiter cushion may be arranged on the lower die.
[0013] The elastic position limiter cushion may be provided with a first steel chain for connecting the elastic position limiter cushion and the lower die.
[0014] The rigid storing limiter may be provided with a second steel chain for connecting the rigid storing limiter and the lower die.
[0015] A rigid storing limiter storing hole for containing the rigid storing limiter may be arranged on the lower die.
[0016] Advantageous effects of the invention over the prior art include: the stamping die includes an elastic storing limiter between the upper die and the lower die in addition to the rigid storing limiter, therefore, if many stamping dies are stacked or if the nitrogen gas spring is degraded after long working hours, the rigid storing limiter can provide the position-limiting function; moreover, prior to die loading and after the stamping die is hoisted to the work platform, the rigid storing limiter can be turned over manually, within the space for the rigid storing limiter after the nitrogen gas spring is relaxed, hence enabling automated die loading. The technical solution of the invention meets the requirement of die stacking, and meets the requirement of automated die loading, thereby saving die changeover time and lowering production costs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a sectional view of a stamping die according to the invention while it is stored separately;
[0018] FIG. 2 is a top view of a lower die according to the invention;
[0019] FIG. 3 is a sectional view of a stamping die according to the invention while it is stacked with many other dies;
[0020] FIG. 4 illustrates the placement of a rigid storing limiter of a stamping die according to the invention before it is installed to a press;
[0021] FIG. 5 illustrates a stamping die according to the invention while it is working.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The invention is described in details through its embodiments in conjunction with the accompany drawings.
[0023] As shown in FIG. 1 and FIG. 2 , a stamping die of the invention includes: a guide pillar 1 for direction guiding, a rigid storing limiter 2 , an upper die 3 , an elastic position limiter cushion 4 , a first steel chain 5 , a working position limiter 6 , an elastic storing limiter, a second steel chain 8 , and a lower die 9 . An elastic position limiter cushion storing hole 10 for containing the elastic position limiter cushion 4 , and a rigid storing limiter storing hole 11 for containing the rigid storing limiter 2 are provided on the lower die 9 .
[0024] The upper die 3 and the lower die 9 are connected and directed to move relatively through the guide pillar 1 . The working position limiter 6 is arranged on the lower die 9 , for position limiting while the stamping die is working. The elastic storing limiter is arranged on the lower die 9 , and according to an embodiment of the invention, may be a nitrogen gas spring 7 . The elastic position limiter cushion 4 is provided between the nitrogen gas spring 7 and the upper die 3 . A counterbore 41 matching the nitrogen gas spring 7 is provided at the lower end of the elastic position limiter cushion 4 that is in contact with the nitrogen gas spring 7 . The depth of the counterbore 41 may range from 3 mm to 5 mm. The elastic position limiter cushion 4 is connected to the lower die 9 via the first steel chain 5 . In a preferred embodiment, four nitrogen gas springs 7 are arranged at the four corners of the stamping die, respectively. The rigid storing limiter 2 is connected to the lower die 9 via the second steel chain 8 . A boss 21 is provided at the lower end of the rigid storing limiter 2 . In an embodiment of the invention, the height of the boss 21 is around 5 mm.
[0025] The heights of the nitrogen gas spring 7 and the rigid storing limiter 2 are calculated and selected based on the size, weight, and length of travel of the stamping die, so that while the stamping die is stored separately the distance between the rigid storing limiter 2 and the upper die 3 is 15 mm or so larger than the distance between the upper end of the elastic position limiter cushion 4 and the upper die 3 . And the distance between the rigid storing limiter 2 and the upper die 3 is larger than the distance between the working position limiter 6 and the upper die 3 . The elastic position limiter cushion storing hole 10 and the rigid storing limiter storing hole 11 are provided on the lower die 9 . The elastic position limiter cushion storing hole 10 is for containing the removed elastic position limiter cushion 4 . And the rigid storing limiter 2 may be stored in the rigid storing limiter storing hole 11 after it is turned over, and the height of the rigid storing limiter 2 now is lower than the height of the working position limiter 6 .
[0026] As shown in FIG. 1 , while the stamping die is stored separately, the nitrogen gas spring 7 provides the position-limiting function, and keeps elastic elements of the die from being damaged. As shown in FIG. 3 , when stamping dies are stored in stacks, if their weight does not exceed the limit of the nitrogen gas spring 7 , it is still the nitrogen gas spring 7 that provides the position-limiting function; and if the weight on the nitrogen gas spring 7 is about to exceed the limit, the nitrogen gas spring 7 is compressed and it is the rigid storing limiter 2 that supports the stamping dies above, thereby effectively protecting elastic elements of the dies.
[0027] Operations of the invention are described as below. When a stamping die is to be put online, stamping dies that are stacked above it are hoisted away, and the stamping die is hoisted to an auxiliary work platform. As shown in FIG. 4 , since the stamping dies stacked above have been removed, the nitrogen gas spring 7 is relaxed to the position where the stamping die is stored separately, and the distance between the upper die 3 and the rigid storing limiter 2 is 15 mm, which, with the 5 mm of the boss 21 at the lower end of the rigid storing limiter 2 subtracted, leaves 10 mm. The space allows for turning over of the rigid storing limiter 2 before the stamping die enters the press, with performance degradation of the nitrogen gas spring 7 after long working hours being taken into account. And the height of the rigid storing limiter 2 after it is turned over is lower than the height of the working position limiter 6 , thereby avoiding affecting working of the stamping die. As shown in FIG. 5 , while the stamping die is working, the elastic position limiter cushion 4 is removed and placed in the elastic position limiter cushion storing hole 10 , and the rigid storing limiter 2 is turned over and placed in the rigid storing limiter storing hole 11 , which ensures that the upper die 3 only contacts with the nitrogen gas spring 7 and working limiter 6 when the upper die 3 moves down, and the nitrogen gas spring 7 now functions as a buffer. Prior to putting the stamping die offline, the elastic position limiter cushion 4 is taken out of the elastic position limiter cushion storing hole 10 , and placed on the nitrogen gas spring 7 . Because of the counterbore 41 at the lower end of the elastic position limiter cushion 4 , the elastic position limiter cushion 4 is steady on the nitrogen gas spring 7 , and the length of travel of the nitrogen gas spring 7 is reduced. Then, the rigid storing limiter 2 is turned back to its storing state, and one of the ends that has the boss 21 is placed in the rigid storing limiter storing hole 11 ; now the stamping die can be closed and put offline to the stamping die storing state.
[0028] The stamping die of the invention can be used in automated stamping lines, preventing elastic elements from being damaged while the stamping dies are stored in stacks, and enabling automated die changing. The invention is highly practicable and compatible, may save stamping die production costs and is easy to be adopted. The invention has a structure easy to be manufactured, has a long service life, and costs little for maintenance.
[0029] Detailed description of the invention is described above in connection with particular preferred embodiments. It should be noted that embodiments of the invention are not limited to the description above. Those skilled in the art may make various modifications or alternations without deviation from the scope of the invention. Those modifications and alternations should be included in the scope of the invention. | A press mould comprises lower mould ( 9 ), upper mould ( 3 ), working limiter ( 6 ) and rigid storing restrictor ( 2 ). The lower mould ( 9 ) and the upper mould ( 3 ) are coupled each other by guide post ( 1 ) having guiding function so that they can move relative to each other. The working limiter ( 6 ) and the rigid storing limiter ( 2 ) are located between the lower mould ( 9 ) and the upper mould ( 3 ). The press mould also includes at least one elastic storing limiter provided between the upper mould ( 3 ) and the lower mould ( 9 ). | 1 |
This is a continuation of copending application Ser. No. 07/423,145 filed on Oct. 19, 1989, now U.S. Pat. No. 5,044,932.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention related to the field of combustion equipment, and more particularly but not by way of limitation, to a burner assembly which substantially reduces the nitrogen oxide content of a flue gas effluent from a furnace and the like.
2. Discussion
Oxides of nitrogen are contaminants emitted during the combustion of industrial fuels. In every combustion process, where nitrogen is present, the high temperatures result in the fixation of some oxides of nitrogen. These compounds are found in flue gases mainly as nitric oxide (NO), with lesser amounts of nitrogen dioxide (NO 2 ) and other oxides. Since nitric acid continues to oxidize to nitrogen dioxide in air at ordinary temperatures, the total amount of nitric oxide plus nitrogen dioxide in a flue gas effluent is referred to simply as nitrogen oxides, or NO x , and expressed as NO 2 .
Emissions of nitrogen oxides from stack gases, through atmospheric reactions, produce "smog". The amount of NO x in vented gases is regulated by various state and federal agencies, especially in such congested areas as that of the Los Angeles Basin in the State of California. Recent rules of the South Coast Air Quality Management District of that state decree that NO x emissions cannot exceed 0.03 lbs/MM BTUs, roughly 25 ppm, (parts per million by volume dry), a NO x level which is below that permitted previously.
Tightening state and federal emission requirements have lead to considerably effort to find ways to remove or prevent the formation of nitrogen oxides in combustion processes so that such gases may be discharged to the atmosphere without further deleterious effect on the environment. Generally, prior art treatment NO x control has involved two methods. The first is that of the treatment of combustion products, sometimes referred to as post combustion treatment.
One such post combustion treatment for removing nitrogen oxides utilizes an absorption medium to absorb the oxides of nitrogen. However, this method results in the formation of either an acidic liquid or other nitrogen containing noxious liquid streams which must be treated further before safe discharge to the environment.
Other post combustion treatments for removing NO x have employed catalysts in combination with ammonia injection for selective catalytic reduction (SCR) of NO x from gaseous effluents. Still other non-catalytic processes have employed ammonia, ammonium formate, ammonium oxalate, ammonium carbonate and the like for selectively reducing NO x content of gaseous effluents. These injection technologies are limited by the reaction kinetics of the injected chemicals; furthermore, such treatments result in undesirable emissions not created by the combustion process, such as ammonia break through and the like.
Another prior art process for reducing NO x employs the concept of reducing NO x in the presence of an excess of a hydrocarbon at elevated temperatures. This process reduces the amount of NO x in the combustion gases, but products such as carbon monoxide, hydrogen, hydrocarbons and particulate carbon, are produced in such quantities that the release of the gases containing these products is prohibitive until additional steps are taken to further treat the gases. U.S. Pat. No. 3,873,671, issued to Reed et al., provides for the burning of a hydrocarbon fuel with less than the stoichiometric amount of oxygen. Combustion products are provided an excess of oxidizable material under conditions that reduce the NO x content, and are then cooled to between about 1200° F. to 2000° F. with a fluid which is substantially free of oxygen. To prevent venting excess combustibles into the atmosphere, the cooled mixture of nitrogen, combustion products and other oxidizable materials is thereafter combusted in a second zone with sufficient oxygen to oxidize substantially all of the oxidizable combustion products while minimizing the oxides of nitrogen. This process achieves NO.sub. x emission reduction to about 50 to 100 ppm.
The second method of dealing with NO x control is that of the prevention of NO x formation in a combustion process. One such method is external flue gas recirculation in which a portion of the flue gas created by a combustion process is mixed with the inlet air fed to the burner. An example is found in U.S. Pat. No. 4,445,843 issued to Nutcher which taught a low NO x burner in which flue gas effluent is recirculated to be mixed with combustion air fed to the burner of a furnace. This system, while working in the prevention of NO x formation, requires additional hardware for flue gas recirculation and has a narrow operating range in terms of effluent oxygen content and flame stability. Achievable NO x levels with this burner design is a NO x emission level of about 45 to 60 ppm.
U.S. Pat. No. 4,505,666 issued to Martin, et al. teaches a staged fuel/staged air low NO x burner which involves creating two combustion zones. The first is created by injecting 40 to 60 percent of the fuel with 80-95 percent of the air, the second by injecting 40-60 percent of the fuel with 5-20 percent of the total air. Achievable NO x levels with this design have been shown in the 40-50 ppm range. There is no provision for utilizing flue gas recirculation.
U.S. Pat. No. 4,629,413 issued to Micheson et al. discloses a low NO x premix burner which delays the mixing of secondary air with the combustion flame and allows cooled flue gas to recirculate. A primary air system uses a jet eductor to entrain combustion air and mix it with fuel to pass the air/fuel mixture to a centrally disposed burner tip to be burned. A secondary air system dispenses air from an annular space formed about the burner so that secondary air is fed to the combustion flame, causing a longer time for secondary air to reach the fuel and thus lowering the peak flame temperature. Further cooling to the flame occurs as a result of small amounts of flue gas being entrained into the base of the less than stoichiometric, fuel rich flame, providing cooling and dilution of the flame. The patent shows a NO x emission level of between about 40 to 120 ppm (corrected to 4% excess oxygen on a dry basis).
With the exception of the Michelson et al. U.S. Pat. No. 4,629,413, the adverse effects of internally recirculated flue gas on flame stability have been avoided. The internal flue gas in a furnace, created by thermal gradients such as in a tubular furnace, is known to recirculate downwardly or back to the burner to interact sufficiently with the flame to cause flame instability or deformation. This deleterious backwash of flue gas was widely recognized and finally obviated by the inclusion of a flue gas deflection barrier which surrounded the burner at a height and spatial orientation to cause the internally recirculated flue gas in the furnace to be diverted away from direct interaction with the flame near the burner. This deflection barrier is well known as a Reed wall.
While NO x emission control by the above described prior art processes and apparatuses has generally proved satisfactory, tighter governmental restrictions are requiring ever improved performances beyond the capability of some of these burner assemblies, and in some instances, even where the prior art is technically capable of achieving the lower permissible NO x emission levels, the captial investment and/or increased operating expenses restrict their applications. There is a need, not only with regard to new installations, but also with regard to retrofit applications, for tighter NO x emission control which minimizes capital outlay and ongoing maintenance and operation expense.
That is, while heretofore known prior art processes and apparatuses are generally capable of reducing NO x emission levels, numerous disadvantages or limitations are presented by such prior art. The heretofore known prior art processes and apparatuses variously fall to provide full emission control; incur substantial downtime due to complexity of equipment; require addition of objectionable chemicals such as ammonia; or lead to additional emission constituents that are themselves recognized as undesirable. Further, the additional costs, including initial capital outlay and ongoing operating expenses, and the liability exposure presented by the heretofore known prior art processes and apparatuses are undesirable.
SUMMARY OF THE INVENTION
The present invention provides a process and apparatus for the substantial reduction or elimination of NO x in a flue gas effluent from a furnace in which a fuel is combusted to form a combustion flame in a combustion zone of the furnace, the furnace being of the variety in which internally recirculated flue gas is encountered. In contrast to prior art combustion teachings, internally recirculated flue gas, or downdraft flue gas, is collected and caused to be driven into reaction contact with the combustion flame.
A staged fuel burner assembly is provided with primary and secondary fuel nozzles, and a burner tile is disposed about the central first fuel nozzle which communicates with air inlet port. The secondary fuel nozzles are disposed peripherally about the burner tile. A flue gas collection assembly comprising a barrier member is provided in proximity to the furnace floor to form a flue gas tunnel to collect and pass downdraft flue gas from the furnace walls to the vicinity of the secondary fuel nozzles where it is aspirated into the combustion zone.
A portion of the collected downdraft flue gas is driven into the combustion zone by fluid driven eductors or the like supported to force the flue gas through access openings in the burner tile.
The present invention effectuates a substantial reduction in the NO x content of the flue gas effluent from the furnace. That is, practice has shown that the total NO x content of a flue gas effluent without externally recirculated flue gas can be controlled within the range of about 10 to 30 ppm or less.
Accordingly, it is the principal object of the present invention to effectuate substantial reduction in the NO x content of a flue gas effluent from a furnace or the like.
Another object of the present invention is to achieve substantial reduction in the NO x content of a flue gas effluent from a furnace or the like without the necessity of externally recirculated flue gas.
Yet another object of the present invention is to achieve the above stated objects while minimizing manufacturing, operating and maintenance costs.
Other objects, features and advantages of the present invention will become clear from the following description when read in conjunction with the drawings and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatical representation of a prior art tubular furnace assembly.
FIG. 2 is a semi-detailed partial cutaway view of a prior art staged fuel burner assembly which finds use in a furnace assembly such as that depicted in FIG. 1.
FIG. 3 is a semi-detailed, partial cutaway elevational view of a staged fuel burner assembly for a furnace and which incorporates the present invention.
FIG. 4 is a plan view taken at 4--4 in FIG. 3.
FIG. 5 is a plan view of a modified burner tile similar to that shown in FIG. 3 with the exception that the modified burner tile of FIG. 5 has been provided several access openings in which are mounted eductor pumps.
FIG. 6 is a view, somewhat enlarged, taken at 6--6 in FIG. 5.
DESCRIPTION
Referring to FIG. 1, shown therein is a tubular furnace assembly 10 which is typical of such units found in the prior art; that is, the furnace assembly 10 illustrates the components usually found in such prior art units.
The furnace assembly 10 has a cylindrically shaped body section 12, a converging medial section 14, a stack section 16, and a furnace floor 18. It will be appreciated that FIG. 1 is illustrative only, and that numerous details of the structure, such as valving, piping, controls, insulation etc., have been omitted throughout the drawings in order to present the disclosure more clearly as such details will be known by a person skilled in the combustion art.
The furnace assembly 10 has a convection section 20 in which is disposed a tube arrangement 22. Provided within the body section 12, and vertically extending along furnace wall 12A, are a plurality of wall tubes 24 which are interconnected to form, with the tube arrangement 22, a unitary heating structure which contains a flowing material, such as water, which is heated by the furnace assembly 10.
The furnace assembly 10 forms a combustion cavity 26 which is generally within the confine of the body section 12. A burner assembly 28 is supported on the furnace floor 18, and a flue gas deflection barrier 30 (or sometimes a burner tile or the like) is supported concentrically about the burner assembly 28. Fuel is fed via a fuel line 32 to a fuel dispensing nozzle (not shown) centrally disposed to a burner tile 34. Combustion air, or some other oxygen bearing fluid such as a mixture of air and externally recirculated flue gas, is fed to an inlet port (not shown) in the furnace floor 18.
Upon ignition by a flame ignitor (not shown), a combustion flame 36 is created in the combustion cavity 26 which produces combustion products exhausted as a flue gas effluent 38 from the stack section 16. As the combustion flame 36 heats the wall tubes 24 and the tube arrangement 22, temperature gradients necessarily occur throughout the tubular furnace assembly 10, causing internal recirculation of a port of the flue gas generated. Downdraft of flue gas is especially pronounced between the wall tubes 24 and the furnace wall 12A for the reason that the gases on the flame side of the wall tubes 24, due to direct exposure to the combustion flame 36, have a higher average temperature than do the gases between the back side of the wall tubes 24 and the furnace wall 12A. This results in downdrafted flue gas 38A as denoted by the flow arrows so enumerated in FIG. 1.
FIG. 2 is a more detailed and enlarged view of a prior art burner assembly 28A, and with the exception that the burner assembly 28A is a staged fuel burner, it is identical to the above described burner assembly 28. Accordingly, the numerals used in FIG. 1 will be used in FIG. 2 to designate the same components. Thus, the burner assembly 28A has the fuel line 32 supporting a fuel dispensing nozzle 40, sometimes referred to as the primary fuel nozzle, and it has a plurality of fuel risers or lines 42 peripherally disposed about the burner tile 34. Supported on each of the upper ends of the fuel lines 42 is a secondary fuel dispensing nozzle 44. Combustion air, or a mixture of air and flue gas, is provided to the combustion flame 36 via an inlet port 46 in the furnace floor 18.
Usually, the major portion of fuel to the furnace assembly 10 is dispensed through the secondary fuel dispensing nozzles 44, while a minor portion of the fuel is dispensed via the first fuel dispensing nozzle 40. In some applications, once the combustion flame 36 is started and stabilized, the fuel to the first fuel dispensing nozzle 40 is reduced and sometimes eliminated during operation, in which case the first fuel dispensing nozzle 40 serves as a flame holder.
As depicted in FIG. 2, the downdrafted flue gas 38A passes downwardly between the wall tubes 24 and the furnace wall 12A and turns toward the combustion flame 36 where it is drawn upwardly along the outer edges of the flame envelope. The deflection barrier 30 serves to turn that portion of the downdrafted flue gas 38A which would flow toward the lower part of the combustion flame 36. The deflection barrier 30, also known as a Reed wall, or some other obstruction, such as burner tile or the like is commonly provided with prior art burner assemblies to minimize interaction of the downdrafted flue gas 38A with the combustion flame 36 at the fuel ignition point of the flame (that is, at the base of the flame) as such interaction results in flame instability, often causing flame snuffing or incomplete fuel combustion.
FIGS. 3 and 4 depict a burner assembly 50 which is constructed in accordance with the present invention. The burner assembly 5 also is a staged fuel burner and is similar to the burner assembly 28A, with the exceptions that will be noted. The burner assembly 50 comprises the fuel line 32 central to, and extensive through, the combustion air inlet port 46 in the furnace floor 18. The burner tile 34 is a generally cylindrically shaped member which circumscribes the first fuel dispensing nozzle 40, and a plurality of fuel lines 42, supporting the secondary fuel dispensing nozzles 44, are peripherally disposed about the burner tile 34.
It will be noted that the burner assembly 50 does not have a fluid gas barrier such as the deflection barrier 30 shown with the burner assembly 28A. The purpose for the exclusion of such commonly used deflection barriers 30 will become clear hereinbelow.
The burner assembly 50 also comprises a flue gas recirculating system 52 which is disposed in the furnace assembly 10 for the purpose of flowing internal recirculating flue gas into combustion reaction with the combustion flame 36, leading to the minimization or elimination of NO x content in the flue gas effluent 38 from the stack 16. The flue gas recirculating system 52 has a flue gas gathering member 54, sometimes also referred to as a barrier member, which is disposed in close proximity to the furnace floor 18. The flue gas gathering member 54 has a central opening 56 which is, by positioning of the flue gas gathering member 54, disposed about the burner tile 34, leaving an annular gap 56A in which the secondary fuel dispensing nozzles 44 are disposed. The flue gas gathering member 54, in cooperation with the furnace floor 18, forms a flue gas tunnel 58, or passageway, which is open near the furnace wall 12A so that some portion of the downdrafted flue gas 38A is collected therein and caused to pass through the annular gap 56A.
The placement of the secondary fuel dispensing nozzles 44 in the annular gap 56A peripherally about the burner tile 34, and thus about the first fuel dispensing nozzle 40, causes the secondary fuel dispensing nozzles 44 to serve as aspirators and, cooperating with the flue gas gathering member 54, the secondary fuel dispensing nozzles 44 aspirate a quantity of the downdrafted flue gas 38A from the flue gas tunnel 58 through the flue gas discharge gap 56A. That is, as flue gas is dispensed from the secondary fuel dispensing nozzles 44 the downdrafted flue gas 38A in the flue gas tunnel 58 is aspirated or driven into the combustion cavity 26 to effect reaction with the combustion flame 36 so that the flue gas effluent 38 from the stack section 16 is caused to have a substantially diminished NO x content.
The aspirating or driving force of the secondary fuel dispensing nozzles 44 is one way in which to pass the collected flue gas 38A from the flue gas tunnel 58 into the combustion zone 26. Another way is depicted in FIGS. 5 and 6. A burner tile 34A is provided which is identical to the burner tile 34 described hereinabove except that the burner tile 34A is provided with several access openings 60 extending through the cylindrical wall at angles α and/or β sufficient to provide gas passage at a direction which is off center to the centrally disposed first fuel dispensing nozzle 40.
The flue gas recirculating force is provided by several eductor pumps 62, one each of such eductor pumps 62 being disposed to have its outlet end 62A fitted into one of the access openings 60 as shown in FIG. 6. The body of each eductor pump 62 has a diverging shape as is conventionally known, and is disposed in the tunnel 58 so that its open inlet end 62B is in communication with the collected flue gas 38A in the tunnel 58. A steam conduit 64 interconnects all of the eductor pumps 62 and provides pressurized steam to each of the eductor pumps 62 through a jet portion 62C at the inlet end 62B of each one. Pressurized steam is fed through the eductor pumps 62 where pressure head is converted to velocity head to draw flue gas 38A from the tunnel 58 and to forcefully propel the mixture of steam and flue gas toward the combustion flame 36. While steam is mentioned as the driving fluid since steam is a frequently available pressurized fluid, other pressurized fluids can also be used effectively to power the eductor pumps 62.
It should be noted that the flue gas recirculating system 52 can be provided with either the driving force of the secondary fuel dispensing nozzles 44 or the eductor pumps 62, or the flue gas recirculating system 52 can be provided with both the driving force of the secondary fuel dispensing nozzles 44 in combination with that of the eductor pumps 62.
The present invention was demonstrated by data obtained during an extensive test object. The test project was carried out using a furnace unit similar to that shown (FIGS. 3 through 6) and described hereinabove to determine the amount of NO x reduction achieved by the present invention.
The objective of the test project was to demonstrate that a burner constructed in accordance with the present invention will produce reduced levels of nitrogen oxides during a combustion process utilizing recirculation of combustion gas products within a fired tubular furnace. The prior art has demonstrated that reduced NO x levels can be achieved by externally recirculating the combustion products from a furnace stack to a burner. That is, a portion of the stack gas effluent is returned to the inlet of the burner. However, this method of recirculation requires substantial equipment and modification to the furnace. The present invention, using internal recirculation of flue gas, also results in reduced levels of NO x using a less expensive installation of structure as described hereinabove.
The test unit had a staged fuel burner which split the fuel into two streams to provide a primary and a secondary combustion zone within the combustion flame. The test unit using this burner showed that the present invention provides the ability to utilize internally recirculated combustion products to reduce NO x levels to substantially below that achieved by a conventional staged fuel burner.
Four parameters were identified that are known to have a major impact on the generation of NO x in a combustion process. These parameters are:
a. Fuel type
b. Oxygen content in the combustion products
c. Furnace temperature
d. Quantity of flue gas recirculation
These parameters were studied in variation during the test project to obtain the necessary data to develop methods to predict the relative impact of each of the parameters on the generation of combustion generated NO x .
Several fuels were tested because it is known that fuel selection has an impact on the level of NO x formed. The fuels tested were:
a. Natural gas
b. 80% hydrogen, 20% natural gas
c. 30% hydrogen, 35% natural gas, 35% propane
d. 50% hydrogen, 50% natural gas
e. 50% hydrogen, 30% natural gas, 20% propane
Because a high oxygen content promotes formation of nitrogen oxides, the test unit was operated at a flue gas oxygen content ranging from less than 1% to greater than 6% by volume.
It is known that the production of NO x increases with increased combustion temperatures, and one factor that influences the combustion temperature is the operating temperature of the furnace. The operating temperatures were varied in the manner described hereinbelow.
The major parameter investigated by the test project was the rate of internal flue gas recirculation. The primary difference between the burner assembly of the present invention and that of a conventional burner is the ability of the present invention to utilize internally recirculated flue gas to further reduce the formation of NO x during a combustion process. Several recirculation rates of flue gas were investigated, with the recirculation flue gas being injected into the primary combustion zone by steam driven eductor pumps. Eductor steam pressure was used as a measure of the recirculation rate.
The test unit on which the test project data was obtained was first operated in a configuration generally in conformity with that shown in FIGS. 1 and 2 herein. That is, the test unit was first operated without the installation of the flue gas recirculation system of the present invention for the purpose of establishing baseline NO x emission levels for the furnace before the installation of the present invention. This data is presented in Table 1 in which is recorded the results of four separate runs using natural gas as the fuel.
The staged fuel burner was run utilizing 30% of the fuel to the primary (center) fuel nozzle and 70% of the fuel to the secondary fuel nozzles peripherally disposed about the primary fuel nozzle. Air was introduced into the burner in a single stage central opening by natural draft.
The following parameters were measured: stack temperature; firebox temperature; and firing rate (reported in million BTUs per hour). The stack gas effluent was monitored using a Teledyne Max 5 flue gas analyzer to determine the excess oxygen (O 2 %) and carbon monoxide (CO ppm). NO x emission was measured using a Thermo Electron Model 10 chemiluminescent NO x analyzer (NO x ppm). NO x is normally reported at 3 percent excess oxygen; therefore, the measured NO x was corrected to this level and is reported as NO x (corrected ppm).
It should be noted that Run 4 in Table 1 is at a reduced firing rate (1.4 MMBTU/HR) and at a high excess oxygen level (13.81%). This represents the high NO x emission level achieved during a startup or during a hot standby condition.
As Table 1 reflects, the corrected NO x achieved during the four runs was as follows: Run 1=34.6 ppm; Run 2=38.7 ppm; Run 3=38.7 ppm; and Run 4=53.8 ppm.
Portions of the data of the test project are presented herein by tables to provide the results and to demonstrate the NO x reduction achieved by the present invention. The following examples are given for illustrative purposes and are not to be construed as limiting the present invention as defined in the appended claims.
The following examples discuss the data obtained with the furnace modified by the addition of the present invention as described hereinabove for FIGS. 3 through 6. In all runs the secondary fuel nozzles were aspirating internal recirculating flue gas into the second stage combustion zone of the combustion flame. The data of the tests are reported identically to that in Table I with the exception that steam driver pressure (STM DRV PF) in psig is added. This parameter is the driving force to cause the eductor pumps to move the internal recirculating flue gas into the primary combustion zone. It should be noted in Table 2 that the lower NO x emission levels recorded when the steam driver pressure is zero (0) were caused by the aspiration effect of the secondary fuel nozzles on the internal recirculating flue gas.
Table II is broken down into 9 tests, and each of these tests has a plurality of runs to demonstrate the effect of the different variables. A description of each such test follows.
EXAMPLE 1
Test 1. The test fuel was natural gas. Effluent oxygen concentration was held in the 2.5% range over the 6 runs that made up the test. The furnace temperature was held as near 1300° F. as possible. Firing rate was held at a constant 4.4 MM BTU/hr. Fuel split was 70% secondary fuel nozzles and 30% primary fuel nozzle. Internally recirculated flue products were driven by means of the eductors into the primary combustion zone. As the eductor pressure increased more internally recirculated flue gas was moved from the gathering system area into the primary combustion zone. Runs 1 thru 6 show the downward trend of NO x formation caused by the injection of internally recirculated flue gas into the primary combustion zone. Run 1, with no recirculation into the primary zone by the eductor pumps, while showing a sizable reduction from the baseline data, did not meet the effluent NO x requirement of approximately 25 ppm for natural gas fuel. By adding recirculated flue gas into the primary combustion zone by the eductor pumps in steps, a gradual decrease in the NO x emissions was noted. Run #6 shows total NO x emission from the furnace of 13.2 ppm. This represents a reduction of 62% from the baseline data. It also demonstrates a reduction of 48% from the furnace configuration without the primary zone eductors. This results in a substantial reduction from the target (0.03 LBS/MM BTU) NO x emission.
EXAMPLE 2
Test 2. Test block conditions were held constant as in Test 1 with the exception that the effluent oxygen concentration was increased to approximately 3%. The fuel was natural gas.
Run 7 shows a NO x emission of 28.6 ppm without the eductor pumps being utilized (STM DRV PR=0). This represents a reduction of 17% when compared with the baseline data. Runs 8-11 show the effect of the educted flue gas when introduced into the primary combustion zone. When data from Run 11 is compared with the baseline data, a reduction of 44% in NOx emission is shown. When Run 11 data is compared with Run 7, a reduction of 47% in NOx reduction is shown. These reductions show the effect of using both the flue gas gathering member and the eductor pumps. The rise in the corrected NO x shows the effect of effluent oxygen concentration on thermal NO x production.
EXAMPLE 3
Test 3. The fuel was natural gas, and the firing rate (4.4 MM BTU/HR) was held at the same rate as in Tests 1 and 2. The effluent oxygen concentration was held around 2.5%. The box temperature was raised to around 1375° F. Fuel split was altered to pass 80% through the secondary fuel nozzles and 20% through the primary fuel nozzle. Again, the eductor pressure (STM DRV PR) was varied. Run No. 12 registered a NO x emission level of 25.5 ppm. When this data is compared with the baseline data of Table I, a reduction of 26% was achieved. As the eductor pressure was increased in Runs 13-16, a decrease in NO x emission was experienced. The best result is shown in Run #16 (12.2 ppm). This shows a reduction from the baseline of 65% and a reduction from Run #12 of 52%. The lower NO x emissions were attributed to the change in fuel split.
EXAMPLE 4
Test 4. The fuel was 80% hydrogen and 20% natural gas. The firing rate was 4.5 MM BTU/HR. Fuel split was 70% to the secondary fuel nozzles and 30% to the primary fuel nozzle. The oxygen concentration was held in the 2-3% range. The furnace temperature was held around 1300° F. Runs 17-19 show the effect of using the eductor pumps to inject internally recirculated gas into the primary combustion zone of the flame. The NO x emission limit for this fuel at 0.03 LBS/MM BTUs is around 30 ppm. Run 18 achieved the best reduction (32%) compared with the 0.03 LBS/MM BTUs limit. The fuel utilized in this test is known to be a high NO x producer is typical of fuels found in certain petrochemical process plants.
EXAMPLE 5
Test 5. The fuel was natural gas. The furnace temperature was held around 1500° F. The eductor pressure was maintained fairly constant. Heat release was held at 4.5 MM BTU/HR for Runs 20-23. Fuel split was 70% to the secondary fuel nozzles and 30% to the primary fuel nozzle. Oxygen concentration was varied from around 2% to 4.8%. Run 21 demonstrated the effect of effluent oxygen concentration on NO x emission when compared with Run 22. As expected, the NO x emission rose with increasing oxygen concentration. Still, a substantial reduction (51%) was achieved when comparing Run 21 to the baseline data of Table I. When compared with the NO x emission limit of 0.03 lbs/MM BTUs (25 ppm) for natural gas as the operating fuel, a reduction of 32% was demonstrated.
EXAMPLE 6
Test 6. The fuel was a mixture of 30% hydrogen, 35% natural gas and 35% propane. This represents a typical refinery fuel gas. The eductor pressure (STM DRV PR) was varied. The furnace temperature was varied from 1300° F. to 1575° F. The firing rate was held constant at 4.5 MM BTU/Hr. Fuel split was 70% to the secondary fuel nozzles and 30% to the primary fuel nozzle. The effluent oxygen concentration was varied in the 2 to 4 percent range. The allowable NO x emission limit of 0.03 lbs/MM BTUs level for this fuel equates to a NOx emission of 25.2 ppm. Runs No. 24-28 show the effect of the increasing the furnace temperature on the NO x emission level. The eductor pressure was held at a low rate in these five runs. It will be noted that the NO x emission limit exceeds the allowable 25.2 ppm limit. Also, in Runs 24-28 the oxygen concentration was varied from 1.8% to 3.15% Runs 29-36 were run at a fairly constant furnace temperature at around 1500° F. The eductor pressure in Runs 29-36 was varied in excess of the previous runs. This resulted in a lowering of the corrected NO x emissions. Run 34, with the oxygen concentration at 3.8%, showed a corrected NO x level of 21.7 ppm. When compared with Run 27, Run 34 shows a reduction in the NO x emission of 26% in spite of a 100° F. furnace temperature increase. Test 36 shows that at 1.85% oxygen concentration and at 1500° F. box temperature, a reduction of 38% was achieved relative to Run 27. A difference of 15% was demonstrated between Run 34 and the 0.03 lbs/MM BTU limit.
EXAMPLE 7
Test 7. The fuel was a mixture of 50% hydrogen and 50% natural gas. The eductor pressure was varied between runs, and the furnace temperature was varied as well as oxygen content. The firing rate was held constant at 4.5 MM BTU/Hr. Fuel split was 70% to the secondary fuel nozzles and 30% to the primary fuel nozzle. The allowable NO x emission level of 0.03 lbs/MM BTUs equates to a limit of 27.0 ppm for this fuel. Run 37 can be used as a baseline for this fuel. It shows a corrected NO x of 31.3 ppm and a box temperature of approximately 1300° F. Runs 38-42 varied the oxygen concentration and the box temperature while holding the eductor pressure (STM DRV PR) constant at 12.0 psig. A marked decrease in the NO x emission in Runs 38-42 was demonstrated when compared to that of Run 37. A 45% decrease in the NO x emission was shown in Run 38 as compared to that of Run 37. The variance in the reported NO x emission levels in Runs 38-42 is believed to be attributable to the changing furnace temperature. Runs 43-45 show the oxygen concentration held at approximately 2%; the furnace temperature at approximately 1500°; and the eductor pressure varied from 15 to 25 psig. A reduction of nearly 45% was achieved in Run 45 as compared with that of Run 37. All of the NO x emission levels of Runs 38-45 were below the allowable level of 27.0 ppm.
EXAMPLE 8
Test 8. The fuel was 50% hydrogen, 30% natural gas and 20% propane, again representing a typical refinery fuel gas. The 0.03 lbs/MM BTUs level for this fuel is 26.1 ppm. Runs 46-50 were conducted at a 3.8 MM BTU/HR heat release. Runs 51 and 52 were at 4.75 MM BTU/HR, and Run 53 represents a turn down case at 1.4 MM BTU/HR All runs were at a constant eductor pressure. In Runs 46-49, with the firebox temperature of approximately 1350° F., the O 2 was varied from 2.18% to 6.03%. Runs 51 and 52 were conducted at a constant 1400° F. box temperature, and O 2 concentration was varied from 1.7% to 3.6%. Run 53 represents the conditions experienced for a furnace during a turn down, a start up condition or a hot standby condition as this run was conducted with a high excess oxygen concentration of 6.3%. All of the reported NO x emission levels were under the 26.1 ppm limit. It should also be noted that the eductor pressure was not decreased during Run 53, indicating the high stability of the flame.
EXAMPLE 9
Test 9. The fuel was 30% hydrogen, 35% natural gas and 35% propane. Again, the eductor pressure was held fairly constant at 20.0 and 25.0 psig. The firebox temperature was allowed to increase from a startup condition of 825° F. to a maximum of 1450° F. The oxygen concentration was varied from between 1.95% to 5.85%. The allowable NOx emission limit of 0.03 lbs/MM BTUs for this fuel is 25.2. Run 54 shows a furnace turn down condition with a high excess oxygen concentration of 7.13%, and the NO x emission level of 29.2 ppm exceeds the allowed level of 25.2 ppm. Runs 55-59 were conducted at 3.8 MM BTU/HR heat release and at a fairly constant box temperature of 1375° F. The NO x emission levels for Runs 55-59 were below the acceptable 25.2 ppm limit. Runs 60-62 were conducted with an increase in firing rate to 4.75 MM BTU/HR and the oxygen concentration was varied between 1.95% and 4.15%. Again, in Runs 60-62 the NO x was below the 25.2 ppm limit.
In conclusion, a wide range of fuels and firing conditions have been demonstrated by the above described examples. The fuels ranged from natural gas, to a heavy fuel gas mixture to a light fuel gas mixture in terms of specific gravity. In most instances the NO x emission levels rotated in Table 2 were below the regulatory permitted level 0.03 lbs/MM BTUs. When the eductor pressure (ST DRV PR) was 15 psig or greater, and when effluent oxygen concentration was below 7%, all fuels tested had NO x emission levels below the 0.03 lbs/MM BTUs level. When compared with baseline data for the natural gas fuels, the data of Table 2 demonstrates a 65% reduction in the emission level of NO x .
It will be clear that the present invention is well adapted to carry out the objects and attain the advantages mentioned as well as those inherent therein. While presently preferred embodiments of the invention have been described for purposes of this desclosure, numerous changes can be made which will readily suggest themselves to those skilled in the art and which are encompassed within the spirit of the invention disclosed and as defined in the appended claims.
TABLE 1______________________________________BASELINE DATARUN NUMBER 1 2 3 4______________________________________O.sub.2 (%) 1.87 2.20 2.10 13.81NO.sub.X (MEASURED PPM) 36.8 40.4 40.6 21.5NO.sub.X (CORRECTED PPM) 34.6 38.7 38.7 53.8CO (PPM) 76.0 29.0 24.0 141.0STACK TEMP (°F.) 1308 1388 1410 901FIREBOX TEMP (°F.) 1314 1379 1403 1009HEAT REL (MMBTU/HR) 4.5 4.5 4.5 1.4______________________________________
TABLE 2__________________________________________________________________________TEST DATA__________________________________________________________________________TEST 1 2RUN NUMBER 1 2 3 4 5 6 7 8 9 10 11__________________________________________________________________________O.sub.2 (%) 2.58 2.50 2.38 2.48 2.47 2.42 3.11 2.97 2.81 3.16 3.13NO.sub.X (MEASURED PPM) 27.4 22.1 20.0 18.5 19.0 13.6 28.5 25.2 19.5 17.6 15.1NO.sub.X (CORRECTED PPM) 26.8 21.5 19.3 18.0 18.4 13.2 28.6 25.2 19.3 17.7 15.2CO (PPM) 56.0 51.0 46.0 53.0 109.0 214.0 23.0 27.0 40.0 52.0 129.0STACK TEMP (°F.) 1276 1308 1332 1330 1331 1318 1310 1322 1323 1313 1313FIREBOX TEMP (°F.) 1321 1333 1338 1329 1361 1297 1323 1326 1323 1304 1299HEAT REL (MMBTU/HR) 4.4 4.4 4.4 4.4 4.4 4.4 4.4 4.4 4.4 4.4 4.4STM DRV PR (PSIG) 0 2 4 6 10 12 0 2 6 10 14__________________________________________________________________________TEST 3 4RUN NUMBER 12 13 14 15 16 17 18 19__________________________________________________________________________O.sub.2 (%) 2.61 2.54 2.35 2.51 2.32 2.83 2.02 2.47NO.sub.X (MEASURED PPM) 26.0 18.7 16.7 15.0 12.7 25.8 21.6 21.4NO.sub.X (CORRECTED PPM) 25.5 18.3 16.1 14.6 12.2 25.6 20.5 20.8CO (PPM) 25.0 144.0 212.0 162.0 458.0 46.0 40.0 36.0STACK TEMP (°F.) 1365 1406 1410 1408 1410 1257 1303 1315FIREBOX TEMP (°F.) 1365 1385 1385 1378 1377 1335 1349 1335HEAT REL (MMBTU/HR) 4.4 4.4 4.4 4.4 4.4 4.5 4.5 4.5STM DRV PR (PSIG) 0 4 8 10 15 15 25 35__________________________________________________________________________TEST 5 6RUN NUMBER 20 21 22 23 24 25 26 27 28 29 30__________________________________________________________________________O.sub.2 (%) 2.38 4.77 2.12 1.86 2.92 2.85 1.84 3.15 3.08 2.93 2.16NO.sub.X (MEASURED PPM) 13.8 15.3 13.9 13.1 25.0 33.9 23.6 29.2 29.6 24.1 26.1NO.sub.X (CORRECTED PPM) 13.4 16.9 13.3 12.3 24.9 33.6 22.2 29.4 29.8 24.0 24.9CO (PPM) 13.0 13.0 12.0 11.0 26.0 79.0 64.0 48.0 38.0 32.0 30.0STACK TEMP (°F.) 1509 1505 1537 1542 1289 1307 1352 1397 1471 1505 1539FIREBOX TEMP (°F.) 1519 1486 1538 1543 1290 1341 1364 1397 1476 1524 1570HEAT REL (MMBTU/HR) 4.5 4.5 4.5 4.5 4.5 4.5 4.5 4.5 4.5 4.5 4.6STM DRV PR (PSIG) 11.5 10.5 10.5 14.0 2.0 2.5 5.0 4.5 4.5 10.0 12.0__________________________________________________________________________TEST 6 7RUN NUMBER 31 32 33 34 35 36 37 38 39 40 41__________________________________________________________________________O.sub.2 (%) 2.45 2.09 3.45 3.79 2.00 1.85 2.91 2.56 3.18 3.10 3.85NO.sub.X (MEASURED PPM) 21.5 19.9 20.8 20.8 21.5 19.5 31.4 17.7 18.8 21.2 22.8NO.sub.X (CORRECTED PPM) 20.9 18.9 21.3 21.7 20.3 18.3 31.3 17.3 18.9 21.4 23.9CO (PPM) 25.0 24.0 24.0 24.0 22.0 21.0 18.0 31.0 9.0 10.0 11.0STACK TEMP (°F.) 1530 1521 1511 1505 1513 1495 1303 1298 1381 1453 1457FIREBOX TEMP (°F.) 1524 1514 1487 1477 1498 1463 1293 1288 1393 1473 1468HEAT REL (MMBTU/HR) 4.5 4.5 4.5 4.5 4.5 4.5 4.5 4.5 4.5 4.5 4.5STM DRV PR (PSIG) 15.0 20.0 22.0 20.0 15.0 28.0 2.5 12.0 12.0 12.0 12.0__________________________________________________________________________TEST 7 8RUN NUMBER 42 43 44 45 46 47 48 49 50 51 52 53__________________________________________________________________________O.sub.2 (%) 1.80 2.13 2.06 2.13 2.18 2.98 4.02 4.55 6.03 1.70 3.60 6.30NO.sub.X (MEASURED PPM) 20.0 19.4 17.4 18.0 20.0 20.0 20.7 20.6 20.6 20.9 23.1 18.6NO.sub.X (CORRECTED PPM) 18.8 18.5 16.5 17.2 19.1 20.0 21.9 22.5 24.7 19.5 23.9 22.0CO (PPM) 8.0 8.0 7.0 7.0 57.0 21.0 20.0 18.0 18.0 17.0 18.0 261STACK TEMP (°F.) 1488 1491 1484 1476FIREBOX TEMP (°F.) 1511 1509 1591 1478 1388 1353 1345 1340 1292 1416 1399 961HEAT REL (MMBTU/HR) 4.5 4.5 4.5 4.5 3.8 3.8 3.8 3.8 3.8 4.75 4.75 1.4STM DRV PR (PSIG) 12.0 15.0 20.0 25.0 25.0 25.0 25.0 25.0 25.0 25.0 25.0 25.0__________________________________________________________________________TEST 9RUN NUMBER 54 55 56 57 58 59 60 61 62__________________________________________________________________________O.sub.2 (%) 7.13 2.27 2.66 4.17 5.85 5.21 2.16 1.95 4.15NO.sub.X (MEASURED PPM) 22.5 16.9 19.4 18.6 18.2 16.7 16.2 18.0 20.9NO.sub.X (CORRECTED PPM) 29.2 16.2 19.0 19.9 21.6 19.0 15.5 17.0 22.3CO (PPM) 106.0 36.0 33.0 29.0 28.0 26.0 20.0 19.0 19.0STACK TEMP (°F.)FIREBOX TEMP (°F.) 825 1384 1434 1377 1349 1313 1380 1436 1450HEAT REL (MMBTU/HR) 1.4 3.8 3.8 3.8 3.8 3.8 4.75 4.75 4.75STM DRV PR (PSIG) 20.0 25.0 25.0 25.0 20.0 20.0 20.0 20.0 20.0__________________________________________________________________________ | An improved process and apparatus for reducing NO x content of flue gas effluent from a furnace, the improvement comprising a burner assembly having a burner and flue gas recirculating system for collecting and passing internally recirculating flue gas into a combustion zone for reaction with a combustion flame. The burner preferably has a plurality of fuel dispensing nozzles peripherally disposed about the combustion zone to aspirate collected internally recirculating flue gas into the combustion zone, and has a plurality of fluid driven eductors to drive further amounts of collected internally recirculating flue gas into the combustion zone. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 13/708,135, titled “WEIGHT-BASED IDENTIFICATION OF THREE DIMENSIONAL PRINTED PARTS,” filed on Dec. 7, 2012, which is a continuation of U.S. patent application Ser. No. 13/455,286 titled “WEIGHT-BASED IDENTIFICATION OF THREE DIMENSIONAL PRINTED PARTS,” filed on Apr. 25, 2012, each of which is hereby incorporated herein by reference in its entirety.
BACKGROUND
[0002] 1. Field of the Disclosure
[0003] The present disclosure relates generally to three dimensional (3D) printing and processing of 3D printed parts. More specifically, embodiments of this disclosure relate to methods and systems for identification of 3D printed parts.
[0004] 2. Description of Background
[0005] 3D printing generally refers to the process of creating a 3D part from a 3D model by printing material layers to create the 3D part. A 3D model from which a 3D part is printed may be any 3D-printable digital model such as a computer-aided design (CAD) model. On-demand 3D printing of custom 3D models has become possible in recent years. For example, there are online services that offer custom 3D printing services. For instance, the online provider Shapeways provides custom 3D printing services wherein customers may upload custom 3D models, select materials and order 3D printed parts to be built from the selected materials.
SUMMARY OF INVENTION
[0006] In a typical on-demand 3D printing process, a 3D model, such as a custom model uploaded by a customer submitting an order, may be assigned to a manufacturer based on the ordered material, shipping location of the customer and available capacity at the manufacturer. The manufacturer may analyze the 3D model to determine whether it is 3D-printable. If the model is printable on a 3D printer, the manufacturer may accept the 3D model and queue it for production planning. Production planning plans 3D print runs, i.e. the build of 3D models. After production planning, one or more 3D parts based on the 3D model may be scheduled to be built inside a tray. Other 3D parts to be built based on other 3D models may also be assigned to the same tray. For example, a tray may be used to build 50-800 3D parts from various 3D models. The tray is then assigned to a 3D printer. After 3D printing, the tray contains multiple 3D printed parts, and these 3D parts may correspond to different 3D models and may also correspond to different customer orders. Therefore, each of the 3D printed parts in a typical tray must be identified so that the parts may be correctly distributed and shipped to customers. As the demand for 3D printing services continues to grow, manufacturers of 3D printed parts need to efficiently process large numbers of 3D printed parts. The identification of a 3D printed part may be achieved by identifying the corresponding 3D model which was used to print that part, thereby matching the 3D printed part with the corresponding 3D model. The process of identifying 3D printed parts within each tray used for 3D printing may be referred to as tray sorting.
[0007] Tray sorting is particularly challenging when large numbers of 3D printed parts are to be identified. Typically, an operator of the manufacturing facility identifies each 3D printed part within a tray based on a contact sheet made for that tray. A contact sheet is made per tray that is to be sorted. The contact sheet for a tray may include images associated with 3D models assigned to that tray, i.e. 3D models used to build the 3D parts in that tray. The operator identifies each 3D printed part by visually matching the part to an image listed on the contact sheet.
[0008] The contact sheet may also include a barcode associated with each 3D model. Upon identifying a 3D printed part, the operator may scan a barcode associated with the matching 3D model for that part, so as to update the status of the part in a computer system and to generate an order card for that part.
[0009] According to one aspect of the invention, it is appreciated that approaches of identifying 3D printed parts is both time consuming and unreliable. For example, a large number of images corresponding to a large number of 3D models may be listed on the contact sheet, thereby making it difficult for the operator to quickly and reliably identify the correct match for a given 3D printed part. Therefore, there is a need to identify 3D printed parts efficiently and reliably in order to effectively scale a 3D printing service to process large volumes of orders for 3D printed parts.
[0010] Aspects and embodiments disclosed herein are directed to providing methods and systems for weight-based identification of 3D printed parts. Various embodiments of the present invention relate to methods and systems that enable efficient and reliable identification of 3D printed parts. Some embodiments may be implemented on a computer system and may provide a convenient user interface to an operator of a manufacturing facility that supplies large quantities of 3D printed parts. According to some embodiments, a system may automatically select a subset of 3D models that may match a 3D printed part based on the weight of the part and theoretical weights computed for each 3D model based on the volume of the 3D model and the density of the material used to print the part. Compared to the typical process where the operator uses a contact sheet to identify the 3D printed parts, some methods and systems of the present disclosure may speed up the process of identifying the parts and increase the identification reliability.
[0011] One aspect of the present disclosure is directed to providing a computer-implemented method for weight-based identification of a three dimensional (3D) printed part, the 3D printed part being printed from a 3D model using a preselected material, the method comprising acts of receiving, by a computer system, an indication of a weight of the 3D printed part; calculating, by the computer system, a plurality of theoretical weights for a plurality of 3D models, each theoretical weight being calculated for a respective 3D model based on a volume of the respective 3D model and a density of the preselected material; comparing the indication of the weight to the plurality of theoretical weights; and selecting a subset of the plurality of 3D models based on a result of the comparing act, the subset having a size less than a total number of the plurality of 3D models. In one embodiment, the act of selecting a subset may further include an act of selecting a 3D model to include in the subset responsive to an act of determining that a deviation of the theoretical weight of the 3D model from the indication of the weight of the 3D printed part does not exceed a predetermined threshold value. In one embodiment, the method may further comprise an act of sorting the subset based on a respective value of deviation of a respective theoretical weight of each 3D model within the subset from the indication of the weight of the 3D printed part. In one embodiment, the method may further comprise an act of receiving the size of the subset.
[0012] In one embodiment, the method may further comprise acts of outputting the subset and receiving a selection of the 3D model corresponding to the 3D printed part from the subset. In one embodiment, the method may further comprise generating a label for the 3D printed part based on the selection of the 3D model. The label may include at least one of a barcode, a model number of the 3D model and an order number for the 3D printed part.
[0013] In one embodiment, the method may further comprise acts of receiving a selection of a tray, the 3D printed part being one of a plurality of 3D printed parts built inside the tray, and selecting the plurality of 3D models based on the selection of the tray. The method may further comprise removing a 3D model corresponding to an identified 3D printed part from the plurality of 3D models.
[0014] Another aspect of the present disclosure is directed to providing a system for weight-based identification of a three dimensional (3D) printed part, the 3D printed part being printed from a 3D model using a preselected material, the system comprising a memory; and a processing unit coupled to the memory, wherein the processing unit is operative to receive an indication of a weight of the 3D printed part; calculate a plurality of theoretical weights for a plurality of 3D models, each theoretical weight being calculated for a respective 3D model based on a volume of the respective 3D model and a density of the preselected material; compare the indication of the weight to the plurality of theoretical weights; and select a subset of the plurality of 3D models in response to comparing the indication of the weight to the plurality of theoretical weights, the subset having a size less than a total number of the plurality of 3D models. In one embodiment, the processing unit being operative to select a subset further includes the processing unit being operative to select a 3D model for inclusion in the subset responsive to a determination that a deviation of the theoretical weight of the 3D model from the indication of the weight of the 3D printed part does not exceed a predetermined threshold value. In one embodiment, the processing unit is further operative to sort the subset based on a respective value of deviation of a respective theoretical weight of each 3D model within the subset from the indication of the weight of the 3D printed part. In one embodiment, the processing unit is further operative to receive the size of the subset.
[0015] In one embodiment, the processing unit is further operative to output the subset and receive a selection of the 3D model corresponding to the 3D printed part from the subset. In one embodiment, the system may further comprise a printer configured to print a label for the 3D printed part based on the selection of the 3D model.
[0016] In one embodiment, the processing unit is further operative to receive a selection of a tray, the 3D printed part being one of a plurality of 3D printed parts built inside the tray, and select the plurality of 3D models based on the selection of the tray. In one embodiment, the processing unit is further operative to remove a 3D model corresponding to an identified 3D printed part from the plurality of 3D models.
[0017] Another aspect of the present disclosure is directed to providing a computer-readable storage medium that stores a set of instructions which when executed perform a method for weight-based identification of a three dimensional (3D) printed part, the 3D printed part being printed from a 3D model using a preselected material, the method executed by the set of instructions comprising receiving an indication of a weight of the 3D printed part; calculating a plurality of theoretical weights for a plurality of 3D models, each theoretical weight being calculated for a respective 3D model based on a volume of the respective 3D model and a density of the preselected material; comparing the indication of the weight to the plurality of theoretical weights; and selecting a subset of the plurality of 3D models based on a result of comparing, the subset having a size less than a total number of the plurality of 3D models.
[0018] Another aspect of the present disclosure is directed to providing a method for weight-based identification of a three dimensional (3D) printed part, the 3D printed part being printed from a 3D model using a preselected material, the method comprising acts of weighing the 3D printed part to generate an indication of a weight of the 3D printed part; calculating a plurality of theoretical weights for a plurality of 3D models, each theoretical weight being calculated for a respective 3D model based on a volume of the respective 3D model and a density of the preselected material; comparing the indication of the weight to the plurality of theoretical weights; and selecting a subset of the plurality of 3D models based on a result of the comparing act, the subset having a size less than a total number of the plurality of 3D models. In one embodiment, the selecting act further includes an act of selecting the subset responsive to an act of determining that a deviation of a theoretical weight of a 3D model from the indication of the weight of the 3D printed part does not exceed a predetermined threshold value. The method may further comprise an act of sorting the subset based on a respective value of deviation of a respective theoretical weight of each 3D model within the subset from the indication of the weight of the 3D printed part. The method may further comprise an act of selecting the size of the subset.
[0019] In one embodiment, the method may further comprise an act of cleaning the 3D printed part prior to the weighing act. In one embodiment, the 3D printed part may be one of a plurality of 3D printed parts built inside a tray, the plurality of 3D models corresponding to the plurality of 3D printed parts built inside the tray.
[0020] In one embodiment, the method may further comprise an act of identifying the 3D model corresponding to the 3D printed part from the subset of the plurality of 3D models. In one embodiment, the identifying act may further include an act of visually comparing at least one 3D model in the subset to the 3D printed part. In one embodiment, the method may further comprise an act of adding a label to the 3D printed part following the identifying act. The method may further comprise an act of routing the 3D printed part to one or more locations in response to the identifying act.
[0021] Still other aspects, embodiments, and advantages of these exemplary aspects and embodiments are discussed in detail below. Embodiments disclosed herein may be combined with other embodiments in any manner consistent with at least one of the principles disclosed herein, and references to “an embodiment,” “some embodiments,” “an alternate embodiment,” “various embodiments,” “one embodiment” or the like are not necessarily mutually exclusive and are intended to indicate that a particular feature, structure, or characteristic described may be included in at least one embodiment. The appearances of such terms herein are not necessarily all referring to the same embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Various aspects of at least one embodiment are discussed below with reference to the accompanying figures, which are not intended to be drawn to scale. The figures are included to provide illustration and a further understanding of the various aspects and embodiments, and are incorporated in and constitute a part of this specification, but are not intended as a definition of the limits of the invention. In the figures, each identical or nearly identical component that is illustrated in various figures is represented by a like numeral. For purposes of clarity, not every component may be labeled in every figure. In the figures:
[0023] FIG. 1 is a flow chart illustrating an exemplary embodiment of a process for weight-based identification of 3D printed parts according to aspects of the present invention;
[0024] FIG. 2 is a display illustrating one example of a user interface including a listing of trays in a computer system implementing weight-based identification of 3D printed parts according to aspects of the present invention;
[0025] FIG. 3 is a display illustrating one example of a user interface for outputting a subset of 3D models in a computer system implementing weight-based identification of 3D printed parts according to aspects of the present invention;
[0026] FIG. 4 is a display illustrating one example of a user interface for generating an order card in a computer system implementing weight-based identification of 3D printed parts according to aspects of the present invention;
[0027] FIG. 5 illustrates one example of a label for a 3D printed part according to aspects of the present invention;
[0028] FIG. 6 is a flow chart illustrating an exemplary process of interacting with a user of the computer implemented user interfaces in FIGS. 3, 4 and 5 ;
[0029] FIG. 7 is a block diagram illustrating one example of a general purpose computer system which may execute a software implementing weight-based identification of 3D printed parts according to aspects of the present invention; and
[0030] FIG. 8 is a diagram illustrating one example of a storage system of the general purpose computer system in FIG. 7 .
DETAILED DESCRIPTION
[0031] Aspects and embodiments are directed to providing efficient and reliable methods for identification of 3D printed parts based on weight. Other aspects and embodiments are directed to systems that implement identification of 3D printed parts based on weight. Efficiency and reliability may be achieved by providing embodiments that enable automatically selecting a subset of 3D models that may correspond to a 3D printed part, based on the weight of the 3D printed part.
[0032] It is to be appreciated that embodiments of the methods and apparatuses discussed herein are not limited in application to the details of construction and the arrangement of components set forth in the following description or illustrated in the accompanying drawings. The methods and apparatuses are capable of implementation in other embodiments and of being practiced or of being carried out in various ways. Examples of specific implementations are provided herein for illustrative purposes only and are not intended to be limiting. In particular, acts, elements and features discussed in connection with any one or more embodiments are not intended to be excluded from a similar role in any other embodiment.
[0033] Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. Any references to embodiments or elements or acts of the systems and methods herein referred to in the singular may also embrace embodiments including a plurality of these elements, and any references in plural to any embodiment or element or act herein may also embrace embodiments including only a single element. The use herein of “including,” “comprising,” “having,” “containing,” “involving,” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. References to “or” may be construed as inclusive so that any terms described using “or” may indicate any of a single, more than one, and all of the described terms. Any references to front and back, left and right, top and bottom, upper and lower, and vertical and horizontal are intended for convenience of description, not to limit the present systems and methods or their components to any one positional or spatial orientation.
[0034] Referring to FIG. 1 , there is illustrated one example of a process 100 for weight-based identification of 3D printed parts according to aspects disclosed herein. Process 100 may be fully or partially implemented in a computer system. In one example, process 100 may be executed by a set of instructions that may be stored on a computer readable storage medium. Process 100 may be implemented, for instance, in software, hardware, or combination thereof used by an operator of a manufacturing facility to efficiently identify 3D printed parts.
[0035] At block 102 of process 100 in FIG. 1 , a tray to be sorted is selected. Tray sorting generally refers to identifying 3D printed parts in each tray after the parts are built in the tray. The tray may include one or more 3D printed parts built based on one or more 3D models. The one or more 3D printed parts in a tray may also correspond to one or more customer orders. In one example, the tray may be selected by a user or operator and the selection of the tray may be input to the computer system implementing weight-based identification. In some embodiments, selecting a tray at block 102 may include selecting or identifying a material and a density of the material used for 3D printing in that tray. In one embodiment, the computer system may be configured to automatically identify the material and associated density used for 3D printing in a selected tray, for example, by retrieving stored material and associated density corresponding to the selected tray. A list of 3D printing materials may be stored in the computer system. Density may also be stored in the computer system as a material property for each 3D printing material.
[0036] Still referring to FIG. 1 , at block 104 of process 100 , theoretical weights may be calculated for one or more 3D models. In the embodiment shown in FIG. 1 , the 3D models for which theoretical weights are calculated may include all the 3D models assigned to the tray selected at block 102 . A 3D model assigned to a tray may be used to build a corresponding 3D part in that tray. In one embodiment, selecting a tray at block 102 may result in selection of one or more 3D models assigned to the selected tray for use at block 104 .
[0037] In one practical example, a group of 1000 3D models that are assigned to a single tray selected at block 102 may be selected for use at block 104 . However, the one or more 3D models used at block 104 may generally include any of the 3D models that were used to print 3D parts in any tray.
[0038] A theoretical weight for a 3D model at block 104 may be calculated by multiplying the volume of the 3D model by the density of the material used to print the 3D model in the selected tray. In one example, the density of the material may be automatically identified upon selecting a tray at block 102 . In one embodiment, block 104 may be performed only once per selected tray. If the selected tray includes 3D parts made from different materials, block 104 may be performed for each 3D printed part based on the density of the material used to print that part.
[0039] At block 106 of process 100 , a 3D printed part that was built in the selected tray may be weighed. In one example, the 3D printed part may be weighed by using a scale. The 3D printed part is weighed after cleaning the part to eliminate any residual weight. Cleaning may be performed prior to selecting the tray at block 102 or prior to weighing the 3D part at block 106 . In other embodiments, if cleaning does not precede weight-based identification, the process of weight-based identification may compensate for an estimated weight of residue.
[0040] In one embodiment, a 3D printed part from the selected tray may be weighed by a user or operator and the weight may be input to the computer system implementing weight-based identification. At block 108 , the weight of the 3D printed part may be compared to the theoretical weights calculated for one or more 3D models. In one embodiment, the comparison may include calculating, for each 3D model used at block 104 , a value representing a deviation of the theoretical weight of the 3D model from the weight of the 3D printed part provided at block 106 . In one example, the values may be absolute values. The comparison may further include checking, for each 3D model used at block 104 , whether a value representing a deviation of its theoretical weight from the weight of the 3D printed part is within a predetermined threshold value of deviation from the weight of the 3D printed part.
[0041] At block 110 of process 100 , a subset of 3D models may be selected from one or more models used at block 104 . The number of 3D models in the subset may be less than the total number of 3D models used at block 104 . The number of 3D models in the subset, i.e. the size of the subset, may be predetermined. In one example, the size may be selected by a user of the weight-based identification process. The subset of 3D models is selected based on comparing, at block 108 , the weight of the 3D printed part with the theoretical weights of one or more 3D models. In one example, a 3D model may be selected for inclusion in the subset of 3D models if a value of deviation of its theoretical weight from the weight of the 3D printed part is within a predetermined threshold value of deviation.
[0042] In one embodiment, selecting a subset of 3D models in at block 110 may further include sorting the 3D models within the subset. Sorting the subset of 3D models may be included within block 110 or as a separate block of process 100 . In one example, the 3D models in the subset may be sorted based on values of deviation of their respective theoretical weights from the weight of the 3D printed part. For example, the subset may be sorted such that the first 3D model in the sorted subset has the smallest value or amount of deviation from the weight of the 3D printed part, thereby being the closest match to the 3D printed part based on weight.
[0043] In a computer implementation of process 100 , the selected subset of 3D models may at least partially be output or presented to a user or operator. In one example, a first subset of 3D models may be presented to the user. Upon receiving a request from the user for more 3D models that may match the 3D printed part, a next subset of 3D models may be presented to the user. The user may switch between viewing the different subsets and may select one or more 3D models for viewing. At block 112 of process 100 , the 3D model that corresponds to the 3D printed part is identified. Block 112 may include comparing 3D models in the subset of block 110 to the 3D printed part. In one embodiment, the comparison may include visual comparison to identify the 3D model that matches the 3D printed part. In one example, the subset of 3D models at block 110 may only include a single 3D model, and at block 112 , the selected 3D model may be confirmed to match the 3D printed part.
[0044] Once the 3D model from which the 3D printed part has been printed is identified at block 112 , a label corresponding to the 3D printed part may be generated at block 114 . The label may include information identifying the 3D printed part. For example, the label may be an order card and may include customer order information, a barcode, the 3D model number that matches the 3D printed part and a code for the material used to print the part (e.g., as shown in FIG. 5 and discussed further below).
[0045] The label may also include a storage bin number corresponding to the 3D printed part. Generating the label may include printing the label and may also include affixing or adding the label to the 3D printed part or a packaging thereof. In some embodiments, process 100 may further include removing an identified 3D printed part from the tray and removing a 3D model corresponding to the identified 3D printed part from the set of one or more 3D models used in process 100 . Removing 3D models from the set of one or more 3D models used for weight based identification of 3D printed parts in a tray may increase the efficiency of weight based identification over time. In some embodiments, process 100 may further include updating a status of the 3D printed part. For example, in a computer system implementation, the status of the 3D printed part may be updated to indicate that the part has been identified or to indicate that a label has been printed for the part. The 3D printed part may be routed to one or more locations using the label. For example, the 3D printed part may be routed from the manufacturing facility to a distribution center, where it may be collected along with any other 3D printed parts from the same customer order and shipped to the customer.
[0046] FIG. 2 illustrates a user interface 120 including a listing of trays in a computer system implementing weight-based identification of 3D printed parts according to aspects of the present disclosure. In one example, interface 120 may be in the form of a table, as shown in FIG. 2 . The interface may include a listing of trays as shown in column 122 . Column 124 lists a date of 3D printing corresponding to each tray. As shown, the listing of trays in column 122 may be sorted by dates of 3D printing in column 124 . In one example, the last tray emerging from the 3D printing process may be listed first.
[0047] Column 126 lists number of items corresponding to each tray. In one example, the number of items in a tray may correspond to the number of 3D printed parts built in that tray. In another example, the number of items may correspond to a sum of the quantity of production orders assigned to that tray, where a production order is a request to produce one or more copies of a 3D part from a single 3D model. Column 128 of interface 120 lists a weight-based sorting feature available for trays that are not yet sorted. In one example, a weight-based sorting feature corresponding to a tray may be selected to launch a computer implemented method for weight-based identification of 3D printed parts in the corresponding tray. In another example, a tray may be selected from the listing of trays that are available for weight-based sorting. Selecting a tray may launch another user interface for weight-based identification of 3D printed parts in the selected tray.
[0048] FIG. 3 illustrates a user interface 130 for weight-based sorting of a selected tray 132 . The tray 132 may be selected using the interface 120 in FIG. 2 . Interface 130 provides an input cell 134 to receive a value indicative of the weight of the 3D printed part. In one example, an operator may enter the weight of a 3D printed part. In another example, a system including the user interface 130 may be configured to obtain a weight of a 3D printed part.
[0049] The user interface 130 may provide a button 136 configured to launch weight-based identification of the 3D printed part corresponding to the entered weight. In one embodiment, clicking on button 136 may result in performing process 100 at blocks 106 and 108 in FIG. 1 . The weight entered in input cell 134 may be compared to one or more of theoretical weights calculated for one or more 3D models assigned to the selected tray 132 . In response to the comparison, a subset of 3D models having theoretical weights that are closest matches to the weight entered in input cell 134 may be selected. Each 3D model in the selected subset may be displayed or output in a respective 3D model window 138 of the user interface 130 . In one example, the 3D model windows 138 may be thumbnails. Each 3D model window 138 may include a zoom button 140 configured to launch the 3D model in a larger overlay window. Each 3D model window 138 may also include a 3D model viewer button 142 configured to launch a 3D viewer application.
[0050] The number of 3D model windows 138 displayed on the user interface 130 may be selected from a menu 144 including predetermined choices. In one example, the predetermined number of 3D models to be output may be chosen to be one of 6, 24 and 60 3D models. However, any other number may be provided for selection in menu 144 . In the example shown in FIG. 3 , 6 3D models are selected, thereby resulting in the display of the 6 3D model windows 138 . In one embodiment, the user interface 130 may be configured to receive as input any number representing the size of the subset of 3D models, wherein the number is less than the total number of 3D models assigned to the selected tray 132 . The user interface 130 may also include buttons 146 and 148 configured to switch between displaying a first subset and a second subset of 3D models selected based on the weight in input cell 134 . In one example, the selected subset of 3D models may be sorted such that the first subset of 3D models that are displayed in user interface 130 more closely match the weight in input cell 134 compared to the second subset of 3D models.
[0051] A user may identify the 3D model that matches the 3D printed part having a weight entered in input cell 134 from a displayed subset of 3D model windows 138 in FIG. 3 . Once the 3D model corresponding to the 3D printed part is identified, the user may request generating a label for the part. FIG. 4 shows one example of a user interface 150 for printing an order card for an identified 3D printed part. The order card may include identifying information for the part. The order card may be generated and displayed in an area 152 of the user interface 150 . The user interface 150 may also provide an interface 154 for updating the status of the 3D printed part. After identifying a 3D printed part, the number of parts left to be identified in a single tray may be reduced. In one example, the number of items corresponding to a tray, as shown in column 126 of FIG. 2 , may be reduced as 3D printed parts are identified in that tray.
[0052] FIG. 5 illustrates one example of an order card printed as a label 156 . The label 156 includes a barcode 158 . In one example, the barcode corresponds to the 3D model that matches the 3D printed part. Label 156 also includes a section 159 having information identifying the 3D printed part. The identifying information may include a customer order number, production order information, a material code corresponding to the material used to 3D print the part, and a 3D model number corresponding to the part. In other examples, the label may include other identifying data.
[0053] FIG. 6 is a flow chart illustrating a computer implemented process 160 of interacting with a user of a weight-based identification system having the user interfaces in FIGS. 3, 4 and 5 . At block 162 , a list of trays to be sorted may be output, for example, by providing the user interface 120 and a listing of trays as shown in column 122 of FIG. 2 . At block 164 , a selection of a tray may be received from a user. For example, the user may select a tray for weight-based sorting using the user interface 120 in FIG. 2 . In response to selecting a tray, process 160 may include launching a user interface 130 as shown in FIG. 3 , for weight-based sorting of the selected tray.
[0054] At block 166 of process 160 , a weight of a 3D printed part built in the tray may be received. The weight may be received using, for example, the input cell 134 in FIG. 3 . Process 160 may include, at block 168 , outputting a subset of 3D models that are closest matches to the 3D printed part having the input weight. Additional subsets of 3D printed parts may be output at block 170 . For example, buttons 146 and 148 of the user interface 130 in FIG. 3 may be used to output additional subsets of 3D models and to switch among displaying the different subsets of 3D models. Process 160 may include receiving a selection of a 3D model from a subset of 3D models at block 172 . For example, a 3D model displayed in a 3D model window 138 of user interface 130 may be selected. A 3D model may be selected for viewing. Selecting a 3D model may include visually comparing the 3D model to the 3D printed part and identifying the 3D model corresponding to the part.
[0055] At block 174 of process 160 , an order card may be generated for the identified part. For example, an order card may be generated using the interface 150 of FIG. 5 . Generating an order card may include printing the order card. Process 160 may further include updating the status of the identified 3D printed part at block 176 . For example, interface 154 of FIG. 4 may be used at block 176 . In some embodiments, process 160 may further include removing a 3D model corresponding to the identified 3D printed part from one or more 3D models used for weight based identification. Embodiments of the processes disclosed herein, such as process 100 in FIG. 1 and process 160 in FIG. 6 may be implemented in a software system that supports the production process for 3D printing at a manufacturing facility. The software system may generally allow tracking of 3D printed parts through the production process and may support processes involved in handling 3D printed parts. For example, the software system may support handling of 3D model files, creating production plans and sending shipments of 3D printed parts to distribution centers. The user interfaces 120 , 130 and 150 may be provided to facilitate interaction with an operator of the manufacturing facility.
[0056] Processes described above are merely illustrative embodiments of systems for weight-based identification of 3D printed parts. Such illustrative embodiments are not intended to limit the scope of the present invention, as any of numerous other implementations for performing the invention. None of the claims set forth below are intended to be limited to any particular implementation of a process of weight-based identification, unless such claim includes a limitation explicitly reciting a particular implementation.
[0057] Processes associated with various embodiments, acts thereof and various embodiments and variations of these methods and acts, individually or in combination, may be defined by computer-readable signals tangibly embodied on a computer-readable medium, for example, a non-volatile recording medium, an integrated circuit memory element, or a combination thereof. Such signals may define instructions, for example, as part of one or more programs that, as a result of being executed by a computer, instruct the computer to perform one or more of the methods or acts described herein, and/or various embodiments, variations and combinations thereof. Such instructions may be written in any of a plurality of programming languages, for example, Java, Visual Basic, C, C#, or C++, Fortran, Pascal, Eiffel, Basic, COBOL, etc., or any of a variety of combinations thereof. The computer-readable medium on which such instructions are stored may reside on one or more of the components of a general-purpose computer described above, and may be distributed across one or more of such components.
[0058] The computer-readable medium may be transportable such that the instructions stored thereon can be loaded onto any computer system resource to implement the aspects of the present invention discussed herein. In addition, it should be appreciated that the instructions stored on the computer-readable medium, described above, are not limited to instructions embodied as part of an application program running on a host computer. Rather, the instructions may be embodied as any type of computer code (e.g., software or microcode) that can be employed to program a processor to implement the above-discussed aspects of the present invention.
[0059] Various embodiments according to the invention may be implemented on one or more computer systems. These computer systems may be, for example, general-purpose computers such as those based on Intel PENTIUM-type processor, Motorola PowerPC, Sun UltraSPARC, Hewlett-Packard PA-RISC processors, or any other type of processor. It should be appreciated that one or more of any type computer system may be used to partially or fully automate weight-based identification of 3D printed parts according to various embodiments of the invention. Further, the software design system may be located on a single computer or may be distributed among a plurality of computers attached by a communications network.
[0060] The computer system may include specially-programmed, special-purpose hardware, for example, an application-specific integrated circuit (ASIC). Aspects of the invention may be implemented in software, hardware or firmware, or any combination thereof. Further, such methods, acts, systems, system elements and components thereof may be implemented as part of the computer system described above or as an independent component.
[0061] A computer system for weight-based identification of 3D printed parts may be a general-purpose computer system that is programmable using a high-level computer programming language. The computer system may be also implemented using specially programmed, special purpose hardware. In a computer system there may be a processor that is typically a commercially available processor such as the well-known Pentium class processor available from the Intel Corporation. Many other processors are available. Such a processor usually executes an operating system which may be, for example, the Windows NT, Windows 2000 (Windows ME), Windows XP, Windows Vista or Windows 7 operating systems available from the Microsoft Corporation, MAC OS Snow Leopard, MAC OS Snow Lion operating systems available from Apple Computer, the Solaris Operating System available from Sun Microsystems, or UNIX available from various sources. Many other operating systems may be used.
[0062] The processor and operating system together define a computer platform for which application programs in high-level programming languages are written. It should be understood that the invention is not limited to a particular computer system platform, processor, operating system, or network. Also, it should be apparent to those skilled in the art that the present invention is not limited to a specific programming language or computer system. Further, it should be appreciated that other appropriate programming languages and other appropriate computer systems could also be used.
[0063] One or more portions of the computer system may be distributed across one or more computer systems coupled to a communications network. These computer systems also may be general-purpose computer systems. For example, various aspects of the invention may be distributed among one or more computer systems configured to provide a service (e.g., servers) to one or more client computers, or to perform an overall task as part of a distributed system. For example, various aspects of the invention may be performed on a client-server system that includes components distributed among one or more server systems that perform various functions according to various embodiments of the invention. These components may be executable, intermediate (e.g., IL) or interpreted (e.g., Java) code which communicate over a communication network (e.g., the Internet) using a communication protocol (e.g., TCP/IP).
[0064] It should be appreciated that the invention is not limited to executing on any particular system or group of systems. Also, it should be appreciated that the invention is not limited to any particular distributed architecture, network, or communication protocol.
[0065] Various embodiments of the present invention may be programmed using an object-oriented programming language, such as SmallTalk, Java, C++, Ada, or C# (C-Sharp). Other object-oriented programming languages may also be used. Alternatively, functional, scripting, and/or logical programming languages may be used. Various aspects of the invention may be implemented in a non-programmed environment (e.g., documents created in HTML, XML or other format that, when viewed in a window of a browser program, render aspects of a graphical-user interface (GUI) or perform other functions). Various aspects of the invention may be implemented as programmed or non-programmed elements, or any combination thereof.
[0066] Further, on each of the one or more systems that include one or more components of a system for weight-based identification of 3D printed parts, each of the components may reside in one or more locations on the system. For example, different portions of the components of a system for weight-based identification of 3D printed parts may reside in different areas of memory (e.g., RAM, ROM, disk, etc.) on the system. Each of such one or more systems may include, among other components, a plurality of known components such as one or more processors, a memory system, a disk storage system, one or more network interfaces, and one or more busses or other internal communication links interconnecting the various components.
[0067] Systems and processes disclosed herein for weight-based identification of 3D printed parts, such as a system including user interfaces 120 , 130 and 150 in FIGS. 2, 3 and 4 , may be implemented on a computer system described below in relation to FIGS. 7 and 8 .
[0068] A system having user interfaces 120 , 130 and 150 in FIGS. 2, 3 and 4 is merely an illustrative embodiment of the weight-based identification system. Such an illustrative embodiment is not intended to limit the scope of the invention, as any of numerous other implementations of the system, for example, are possible and are intended to fall within the scope of the invention. None of the claims set forth below are intended to be limited to any particular implementation of the system unless such claim includes a limitation explicitly reciting a particular implementation.
[0069] Various aspects of the invention may be implemented as specialized software executing in a general-purpose computer system 180 such as that shown in FIG. 7 . The computer system 180 may include a processor 182 connected to one or more memory devices 184 , such as a disk drive, memory, or other device for storing data. Memory 184 is typically used for storing programs and data during operation of the computer system 180 . Components of computer system 180 may be coupled by an interconnection mechanism 186 , which may include one or more busses (e.g., between components that are integrated within a same machine) and/or a network (e.g., between components that reside on separate discrete machines). The interconnection mechanism 186 enables communications (e.g., data, instructions) to be exchanged between system components of system 180 . Computer system 180 also includes one or more input devices 188 , for example, a keyboard, mouse, trackball, microphone, touch screen, and one or more output devices 190 , for example, a printing device, display screen, and/or speaker. In addition, computer system 180 may contain one or more interfaces (not shown) that connect computer system 180 to a communication network (in addition or as an alternative to the interconnection mechanism 186 .
[0070] The storage system 192 , shown in greater detail in FIG. 8 , typically includes a computer readable and writeable nonvolatile recording medium 194 in which signals are stored that define a program to be executed by the processor or information stored on or in the medium 194 to be processed by the program. The medium may, for example, be a disk or flash memory. Typically, in operation, the processor causes data to be read from the nonvolatile recording medium 194 into another memory 196 that allows for faster access to the information by the processor than does the medium 194 . This memory 196 is typically a volatile, random access memory such as a dynamic random access memory (DRAM) or static memory (SRAM). It may be located in storage system 192 , as shown, or in memory system 184 , not shown. The processor 182 generally manipulates the data within the integrated circuit memory 184 , 196 and then copies the data to the medium 194 after processing is completed. A variety of mechanisms are known for managing data movement between the medium 194 and the integrated circuit memory element 184 , 196 , and the invention is not limited thereto. The invention is not limited to a particular memory system 184 or storage system 192 .
[0071] Although computer system 180 is shown by way of example as one type of computer system upon which various aspects of the invention may be practiced, it should be appreciated that aspects of the invention are not limited to being implemented on the computer system as shown in FIG. 7 . Various aspects of the invention may be practiced on one or more computers having a different architecture or components that that shown in FIG. 7 .
[0072] Computer system 180 may be a general-purpose computer system that is programmable using a high-level computer programming language. Computer system 180 may be also implemented using specially programmed, special purpose hardware. In computer system 180 , processor 182 is typically a commercially available processor such as the well-known Pentium class processor available from the Intel Corporation. Many other processors are available. Such a processor usually executes an operating system which may be, for example, the Windows NT, Windows 2000 (Windows ME), Windows XP, Windows Vista or Windows 7 operating systems available from the Microsoft Corporation, MAC OS Snow Leopard, MAC OS Snow Lion operating systems available from Apple Computer, the Solaris Operating System available from Sun Microsystems, or UNIX available from various sources. Many other operating systems may be used. The processor and operating system together define a computer platform for which application programs in high-level programming languages are written. It should be understood that the invention is not limited to a particular computer system platform, processor, operating system, or network. Also, it should be apparent to those skilled in the art that the present invention is not limited to a specific programming language or computer system. Further, it should be appreciated that other appropriate programming languages and other appropriate computer systems could also be used.
[0073] One or more portions of the computer system may be distributed across one or more computer systems (not shown) coupled to a communications network. These computer systems also may be general-purpose computer systems. For example, various aspects of the invention may be distributed among one or more computer systems configured to provide a service (e.g., servers) to one or more client computers, or to perform an overall task as part of a distributed system. For example, various aspects of the invention may be performed on a client-server system that includes components distributed among one or more server systems that perform various functions according to various embodiments of the invention. These components may be executable, intermediate (e.g., IL) or interpreted (e.g., Java) code which communicate over a communication network (e.g., the Internet) using a communication protocol (e.g., TCP/IP).
[0074] It should be appreciated that the invention is not limited to executing on any particular system or group of systems. Also, it should be appreciated that the invention is not limited to any particular distributed architecture, network, or communication protocol.
[0075] Various embodiments of the present invention may be programmed using an object-oriented programming language, such as SmallTalk, Java, C++, Ada, or C# (C-Sharp). Other object-oriented programming languages may also be used. Alternatively, functional, scripting, and/or logical programming languages may be used. Various aspects of the invention may be implemented in a non-programmed environment (e.g., documents created in HTML, XML or other format that, when viewed in a window of a browser program, render aspects of a graphical-user interface (GUI) or perform other functions). Various aspects of the invention may be implemented using various Internet technologies such as, for example, the well-known Common Gateway Interface (CGI) script, PHP Hyper-text Preprocessor (PHP), Active Server Pages (ASP), HyperText Markup Language (HTML), Extensible Markup Language (XML), Java, JavaScript, Asynchronous JavaScript and XML (AJAX), Flash, and other programming methods. Various aspects of the invention may be implemented as programmed or non-programmed elements, or any combination thereof.
[0076] Having described above several aspects of at least one embodiment, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure and are intended to be within the scope of the invention. Accordingly, the foregoing description and drawings are by way of example only, and the scope of the invention should be determined from proper construction of the appended claims, and their equivalents. | Methods and systems for weight-based identification of three dimensional (3D) printed parts. Various embodiments disclosed herein may permit reliable processing of 3D printed parts to effectively scale a 3D printing service to large volumes of orders for 3D printed parts. | 1 |
BACKGROUND OF THE INVENTION
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
This invention relates to methods for controlling lost circulation in subterranean wells, in particular, fluid compositions and methods for operations during which the fluid compositions are pumped into a wellbore, enter voids in the subterranean-well formation through which wellbore fluids escape, and form a seal that limits further egress of wellbore fluid from the wellbore.
During construction of a subterranean well, drilling and cementing operations are performed that involve circulating fluids in and out of the well. The fluids exert hydrostatic and pumping pressure against the subterranean rock formations, and may induce a condition known as lost circulation. Lost circulation is the total or partial loss of drilling fluids or cement slurries into highly permeable zones, cavernous formations and fractures or voids. Such openings may be naturally occurring or induced by pressure exerted during pumping operations. Lost circulation should not be confused with fluid loss, which is a filtration process wherein the liquid phase of a drilling fluid or cement slurry escapes into the formation, leaving the solid components behind.
Lost circulation can be an expensive and time consuming problem. During drilling, this loss may vary from a gradual lowering of the mud level in the pits to a complete loss of returns. Lost circulation may also pose a safety hazard, leading to well-control problems and environmental incidents. During cementing, lost circulation may severely compromise the quality of the cement job, reducing annular coverage, leaving casing exposed to corrosive downhole fluids, and failing to provide adequate zonal isolation. Lost circulation may also be a problem encountered during well-completion and workover operations, potentially causing formation damage, lost reserves and even loss of the well.
Lost-circulation solutions may be classified into three principal categories: bridging agents, surface-mixed systems and downhole-mixed systems. Bridging agents, also known as lost-circulation materials (LCMs), are solids of various sizes and shapes (e.g., granular, lamellar, fibrous and mixtures thereof). They are generally chosen according to the size of the voids or cracks in the subterranean formation (if known) and, as fluid escapes into the formation, congregate and form a barrier that minimizes or stops further fluid flow. Surface-mixed systems are generally fluids composed of a hydraulic cement slurry or a polymer solution that enters voids in the subterranean formation, sets or thickens, and forms a seal that minimizes or stops further fluid flow. Downhole-mixed systems generally consist of two or more fluids that, upon making contact in the wellbore or the lost-circulation zone, form a viscous plug or a precipitate that seals the zone.
A thorough overview of LCMs, surface-mixed systems and downhole-mixed systems, including guidelines for choosing the appropriate solution for a given situation, is presented in the following reference: Daccord G, Craster B, Ladva H, Jones T G J and Manescu G: “Cement-Formation Interactions,” in Nelson E and Guillot D (eds.): Well Cementing —2 nd Edition, Houston: Schlumberger (2006): 202-219.
Swellable materials may be employed as bridging agents, either alone or in a mixture of different bridging agents. The swellable materials increase in size and/or form gels upon mixing with aqueous or hydrocarbon-base fluids, depending on their chemistries. For example, this concept was described by Klaas et al. in U.S. Pat. No. 2,935,472 and, more recently, by Creel et al. in U.S. Patent Application 2006/0086501 A1.Broad varieties of swellable polymers that are suitable for curing lost circulation are revealed by McKinley et al. in U.S. Pat. No. 4,526,240.
Swellable polymers suffer from a fundamental problem in that their ability to swell is limited by the presence of soluble salts in the carrier fluid that increase ionic strength. For example, exposing swellable polymers to formation waters that contain high concentrations of electrolytes (e.g., Na + and Ca 2+ ) severely limits the degree to which swelling occurs, and reduces the polymers' ability to address lost circulation. Therefore, there is a need for a swellable-polymer system that is relatively independent of fluid chemistry, and may swell or expand under a broad range of downhole conditions.
SUMMARY
Some embodiments provide methods and techniques to seal voids and cracks in subterranean-formation rock, thereby minimizing or stopping fluid flow between the formation rock and the wellbore of a subterranean well.
In a first aspect, embodiments are methods of treating a subterranean well with the aim of sealing voids that cause lost circulation in formations. The methods include preparing a carrier fluid containing compressed expandable foam. The carrier-fluid may be placed into a subterranean lost-circulation zone by various methods, including, but not limited to (1) pumping through tubulars (e.g., drill pipe, coiled tubing and casing); (2) pumping in the annulus between tubulars and the subterranean-formation wall; and (3) transporting the carrier fluid inside a dispensing device (e.g., a dump bailer), lowering the device to the lost-circulation zone and releasing the fluid. As the carrier fluid enters the lost-circulation zone, the foam expands and forms a barrier that minimizes or blocks further fluid flow into the lost-circulation zone.
The foam composition may include polyurethane, polyether, polyester, polyimide, naturally occurring sponge, melamine and mixtures thereof. The uncompressed foam density preferably ranges between about 0.01 g/cm 3 and 0.3 g/cm 3 , most preferably between 0.015 g/cm 3 and 0.2 g/cm 3 . The foam compression may be such that the compressed-foam volume is about 3 to 30 times lower than the uncompressed-foam volume.
Dissolvable polymers may also be imbibed into the compressed foam to help control when and where foam expansion occurs in the well. Such polymers include, but are not limited to, polyvinylalcohol, partially saponified polyvinylalcohol, polyvinylpyrrolidone, methylcellulose, cellulose acetate, carboxymethylcelluose, hydroxyethylcellulose, polyethylene oxide, gelatin, dextrin, agar, pectin, polyvinylacetate, copolymers of ethylene and vinyl acetate, and mixtures thereof.
The foam-containing carrier fluid may be supplemented by the addition of one or more lost-circulation materials having various shapes such as particles, flakes, or fibers and combinations thereof. In addition, a separate carrier fluid containing the aforementioned lost-circulation materials may be placed behind the foam-containing carrier fluid. Additionally, further reinforcement of the barrier may be achieved by placing a cement slurry across the lost-circulation zone.
In further aspects, embodiments are methods of treating a subterranean well with the aim of sealing voids in formations that cause lost circulation. The methods include preparing a carrier fluid that contains encapsulated compressed foam. The carrier-fluid containing the foam capsules may be placed into a subterranean lost-circulation zone by various methods, including, but not limited to (1) pumping through tubulars (e.g., drill pipe, coiled tubing and casing); (2) pumping in the annulus between tubulars and the subterranean-formation wall; and (3) transporting the carrier fluid inside a dispensing device (e.g., a dump bailer), lowering the device to the lost-circulation zone and releasing the fluid. As the carrier fluid enters a lost-circulation zone, the capsule coating dissolves and releases the compressed foam. The compressed foam then expands to its original size, forming a barrier that minimizes or blocks further flow of carrier fluid into the lost-circulation zone.
The foam composition may include polyurethane, polyether, polyester, polyimide, naturally occurring sponge, melamine and mixtures thereof. The capsule may be fabricated from dissolvable polyvinylalcohol, partially saponified polyvinylalcohol, polyvinylpyrrolidone, methylcellulose, cellulose acetate, carboxymethylcelluose, hydroxyethylcellulose, polyethylene oxide, gelatin, dextrin, agar, pectin, polyvinylacetate, copolymers of ethylene and vinyl acetate, and mixtures thereof.
The capsule coating may include one or more dissolvable polymers selected from the list comprising polyvinylalcohol, partially saponified polyvinylalcohol, polyvinylpyrrolidone, methylcellulose, cellulose acetate, carboxymethylcelluose, hydroxyethylcellulose, polyethylene oxide, gelatin, dextrin, agar, pectin, polyvinylacetate, and copolymers of ethylene and vinyl acetate.
The capsule length may vary from about 0.5 cm to 10 cm, preferably between about 1 cm to 5 cm. The capsule diameter may vary from about 1 mm to 30 mm, preferably between about 5 mm to 20 mm. The volume ratio between the coating and the compressed foam (coating:compressed foam) may vary between about 5:95 to 80:20, preferably between about 10:90 to 60:40, even more preferably about 50:50.
Dissolvable polymers may also be imbibed into the compressed foam to help control when and where foam expansion occurs in the well. Such polymers include, but are not limited to, polyvinylalcohol, partially saponified polyvinylalcohol, polyvinylpyrrolidone, methylcellulose, cellulose acetate, carboxymethylcelluose, hydroxyethylcellulose, polyethylene oxide, gelatin, dextrin, agar, pectin, polyvinylacetate, copolymers of ethylene and vinyl acetate, and mixtures thereof.
The encapsulated-foam-containing carrier fluid may be supplemented by the addition of one or more lost-circulation materials such as particles, flakes, or fibers and mixtures thereof. In addition a separate carrier fluid containing the aforementioned lost-circulation materials may be placed behind the foam-containing carrier fluid. Further reinforcement of the barrier may be achieved by placing a cement slurry across the lost-circulation zone.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows carrier fluid containing particles of encapsulated compressed expandable foam, entering a lost-circulation zone.
FIG. 2 shows the foam expanding in the lost-circulation zone after the capsules degrade, forming a barrier that obstructs further fluid flow.
FIG. 3 shows the introduction of additional reinforcing carrier fluid containing lost-circulation materials.
FIG. 4 shows further reinforcement of the flow barrier in the lost-circulation zone by a cement system.
FIG. 5 shows the results of flow-rate tests that demonstrate the feasibility of encapsulated compressed foam as a lost-circulation material.
DETAILED DESCRIPTION
At the outset, it should be noted that in the development of any such actual embodiment, numerous implementation—specific decisions must be made to achieve the developer's specific goals, such as compliance with system related and business related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time consuming but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. In addition, the composition used/disclosed herein can also comprise some components other than those cited. In the summary of the invention and this detailed description, each numerical value should be read once as modified by the term “about” (unless already expressly so modified), and then read again as not so modified unless otherwise indicated in context. Also, in the summary of the invention and this detailed description, it should be understood that a concentration range listed or described as being useful, suitable, or the like, is intended that any and every concentration within the range, including the end points, is to be considered as having been stated. For example, “a range of from 1 to 10” is to be read as indicating each and every possible number along the continuum between about 1 and about 10. Thus, even if specific data points within the range, or even no data points within the range, are explicitly identified or refer to only a few specific, it is to be understood that inventors appreciate and understand that any and all data points within the range are to be considered to have been specified, and that inventors possessed knowledge of the entire range and all points within the range.
We have discovered that carrier fluids comprising particles of compressed expandable foam have the ability to limit fluid flow in passageways of a size consistent with many lost-circulation zones in subterranean wells. This discovery has led to the development of methods by which such fluids may be applied to solving lost-circulation problems.
A first aspect is methods of treating a subterranean well with the aim of sealing voids in formations that cause lost circulation. The method comprises preparing a carrier fluid containing compressed expandable foam. The carrier-fluid may be placed into a subterranean lost-circulation zone by various methods, including, but not limited to (1) pumping through tubulars (e.g., drill pipe, coiled tubing and casing); (2) pumping in the annulus between tubulars and the subterranean-formation wall; and (3) transporting the carrier fluid inside a dispensing device (e.g., a dump bailer), lowering the device to the lost-circulation zone and releasing the fluid. As the carrier fluid enters the lost-circulation zone, the foam expands and forms a barrier that minimizes or blocks further fluid flow into the lost-circulation zone.
In the present context, the carrier fluid may be selected from common types of oilfield service fluids that are chemically compatible with the coating materials. For example, fluids viscosified by polymers, bentonite, or surfactants. Specific examples are spacers, water-based muds, linear or crosslinked fracturing fluids, or lost circulation pills. In terms of compatibility, obvious incompatibility needs to be avoided, e.g. Polyvinylalcohol type of coating materials are known to be incompatible with certain types of crosslinkers such as borate or zirconate for fracturing fluids.
The foam composition may comprise polyurethane, polyether, polyester, polyimide, naturally occurring sponge, melamine and mixtures thereof. The uncompressed foam density may range between about 0.01 g/cm 3 and 0.3 g/cm 3 , most preferably between 0.015 g/cm 3 and 0.2 g/cm 3 . The foam compression may be such that the compressed-foam volume is about 3 to 30 times lower than the uncompressed-foam volume.
Dissolvable polymers may also be imbibed into the compressed foam to help control when and where foam expansion occurs in the well. Such polymers include, but are not limited to, polyvinylalcohol, partially saponified polyvinylalcohol, polyvinylpyrrolidone, methylcellulose, cellulose acetate, carboxymethylcelluose, hydroxyethylcellulose, polyethylene oxide, gelatin, dextrin, agar, pectin, polyvinylacetate, copolymers of ethylene and vinyl acetate, and mixtures thereof.
The foam-containing carrier fluid may be supplemented by the addition of one or more lost-circulation materials such as, for example, fibrous (cedar bark, shredded cane stalks, mineral fiber and hair), flaky (mica flakes and pieces of plastic or cellophane sheeting) or granular (ground and sized limestone or marble, wood, nut hulls, Formica, corncobs and cotton hulls) and combinations thereof. In addition, a separate carrier fluid containing the aforementioned lost-circulation materials may be placed behind the foam-containing carrier fluid. Further reinforcement of the barrier may be achieved by placing a cement slurry across the lost-circulation zone.
The second aspect, illustrated in FIGS. 1-4 , includes treating a subterranean well ( 1 ) with the aim of sealing voids in formations that cause lost circulation. The method includes preparing a carrier fluid that contains encapsulated compressed foam ( 2 ). As the carrier fluid containing compressed-foam capsules enters a lost-circulation zone ( 3 ), the capsule coating dissolves and releases the compressed foam. The compressed foam then expands to its original size ( 4 ), forming a barrier that minimizes or blocks further flow of carrier fluid into the formation. Without wishing to be bound by any theory, the inventors believe that during placement, the temperature of the carrier fluid does not equalize the bottom hole static temperature due to cool down effect; however, once bridged inside the fracture, the coating experiences the increasing temperature downhole and thus the kinetic of reaction is increase allowing a degradation of the coating and thus the release of the expandable foam.
The carrier-fluid containing the foam capsules may be placed into a subterranean lost-circulation zone by various methods, including, but not limited to (1) pumping through tubulars (e.g., drill pipe, coiled tubing and casing); (2) pumping in the annulus between tubulars and the subterranean-formation wall; and (3) transporting the carrier fluid inside a dispensing device (e.g., a dump bailer), lowering the device to the lost-circulation zone and releasing the fluid.
The foam composition may include polyurethane, polyether, polyester, polyimide, naturally occurring sponge, melamine and mixtures thereof. The capsule may be fabricated from dissolvable polyvinylalcohol, partially saponified polyvinylalcohol, polyvinylpyrrolidone, methylcellulose, cellulose acetate, carboxymethylcelluose, hydroxyethylcellulose, polyethylene oxide, gelatin, dextrin, agar, pectin, polyvinylacetate, copolymers of ethylene and vinyl acetate, and mixtures thereof.
The capsule coating may include one or more dissolvable polymers selected from the list comprising polyvinylalcohol, partially saponified polyvinylalcohol, polyvinylpyrrolidone, methylcellulose, cellulose acetate, carboxymethylcelluose, hydroxyethylcellulose, polyethylene oxide, gelatin, dextrin, agar, pectin, polyvinylacetate, and copolymers of ethylene and vinyl acetate.
The capsule length may vary from about 0.5 cm to 10 cm, preferably between about 1 cm to 5 cm. The capsule diameter may vary from about 1 mm to 30 mm, preferably between about 5 mm to 20 mm. The volume ratio between the coating and the compressed foam (coating:compressed foam) may vary between about 5:95 to 80:20, preferably between about 10:90 to 50:50.
Dissolvable polymers may also be imbibed into the compressed foam to help control when and where foam expansion occurs in the well. Such polymers include, but are not limited to, polyvinylalcohol, partially saponified polyvinylalcohol, polyvinylpyrrolidone, methylcellulose, cellulose acetate, carboxymethylcelluose, hydroxyethylcellulose, polyethylene oxide, gelatin, dextrin, agar, pectin, polyvinylacetate, copolymers of ethylene and vinyl acetate, and mixtures thereof.
The encapsulated-foam-containing carrier fluid may be supplemented by the addition of one or more lost-circulation materials such as particles, flakes, fibers and mixtures thereof. Such addition may further help the lost circulation control. In addition, a separate carrier fluid containing the aforementioned lost-circulation materials ( 5 ) may be placed behind the foam-containing carrier fluid. Further reinforcement of the barrier may be achieved by placing a cement slurry ( 6 ) across the lost-circulation zone.
EXAMPLES
The following example serves to further illustrate the invention.
Example 1
A plugging test was performed in a flow line equipped with a 6 mm×20 mm slot that simulated the opening of a lost-circulation zone. Encapsulated open-cell polyurethane foam was purchased from Westminster Toys, Inc., 159 Armour Drive, Atlanta, Ga., USA 30324. The product name was “Magic Capsules.” The capsule dimensions were: 1 cm long and 30 mm diameter. The dimensions of the uncompressed polyurethane foam were 2 cm×2 cm×0.5 cm, and the foam density was 0.032 g/cm 3 before compression. The foam was compressed 30 times by volume inside the capsules. The capsules were fabricated from water-soluble polyvinylalcohol (molecular weight: 14,000-40,000; degree of hydrolysis: 80-90 percent).
A 10-L reservoir was filled with water and raised to a height of 2 m. The flow line was connected such that the slot was 0.5 m from the ground. The flow rate through the slot was measured with plain water at 40° C. to establish a baseline. Next, one capsule was added. The capsule degraded, and the volume of the compressed foam increased fivefold. After expansion the flow rate through the slot was measured. The results, shown in FIG. 5 , reveal that the flow rate decreased by a factor of three. This result demonstrates the feasibility of using expandable foam for curing lost circulation arising from formation voids. | Methods for controlling lost circulation in subterranean wells, and in particular, fluid compositions and methods for operations during which the fluid compositions are pumped into a wellbore, enter voids in the subterranean-well formation through which wellbore fluids escape, and form a seal that limits further egress of wellbore fluid from the wellbore. The methods include preparing a carrier fluid containing compressed expandable foam that may be encapsulated. The carrier fluid is then placed into a lost-circulation zone, whereupon the foam expands to form a barrier that minimizes or blocks further ingress of carrier fluid. Lost-circulation control may be supplemented by introducing additional lost-circulation materials, pumping a cement slurry behind the foam-containing carrier fluid or both. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation application of U.S. Ser. No. 13/367,096, filed Feb. 6, 2012, entitled “SAFETY PROTECTION APPARATUS FOR PERSONNEL ON OIL DRILLING DERRICKS”, the entire contents of which is hereby expressly incorporated herein by reference.
BACKGROUND OF THE INVENTION
This invention relates generally to safety protection devices and more particularly to methods and apparatus for protecting personnel on an oil drilling derrick.
Oil and gas exploration has been a hazardous undertaking since it began more than 150 years ago. During modern drilling rig operations, one of the times of greatest risk to personnel is when the rig is either running pipe into the well or pulling pipe out of the well. The “derrick man” is positioned up in the derrick (approximately 30 m) on a standard triple stand derrick. His job is to pull and rack the stands (three lengths of pipe joined together) of pipe into the racking board so the stands can be stored in an orderly arrangement. He is required to extend himself out from the racking board, retrieve the top of the stand, and guide it onto the racking board. The rig is usually equipped with at least one of several fall restraint and fall arrest devices in the event he should fall off the racking board. These could include devices such as a full body harness or fail arrest retracting device.
At times, the derrick man may forget to or is distracted from attaching to the fall protection system. This lack of attention could cause the derrick man to be severely injured, perhaps even fatally injured. Also, his fall may present a serious hazard to personnel on the rig floor.
Nevertheless, in normal drilling operations, personnel may be required to be in areas or jobs that are inherently hazardous. There are many safety systems on the market that are or can be effective if they are in proper and continuous use. However, rig operations start and stop repeatedly during any working shift. Thus, it is common for the derrick man to take his safety equipment off and on during his shift for breaks, for comfort while waiting on rig maintenance, to perform other functions that cannot be performed while hooked to the safety gear, or for other reasons. When operations restart, the derrick man may or may not remember to reattach all of his safety gear.
The person on the rig who is in charge of controlling operations is the driller. The driller cannot see all of the personnel involved in rig operations from his location, including the derrick man who may be located 30 m above him. Thus, the driller presently has no way of verifying that the derrick man is properly harnessed and ready to work every time rig operations are restarted.
Every known drilling company has specific policies regarding personnel safety during rig operations. OSHA also has regulations relating to these same issues. Insurance companies providing workers' compensation insurance have requirements for safety equipment that insureds must meet. But ultimately, safety depends upon whether personnel follow company policy and use the provided safety equipment.
Truly safe operations depend upon each of the rig hands being where they are supposed to be for any given rig operation. Because the driller is rarely, if ever, in a position to verify the location of all of the members of the crew during operations, it would be desirable to provide a comprehensive approach to monitoring crew behavior and location.
It is thus also be desirable to provide apparatus to make drilling operations safer. It is also desirable to provide apparatus that assist in changing the behavior of personnel to make safety systems more effective.
SUMMARY OF THE INVENTION
In one aspect, some configurations of the present invention therefore provide a safety apparatus for personnel on an oil drilling rig. The safety apparatus includes a cylindrical quick disconnect switch having a receptacle and a plunger. The receptacle has an open circuit pair of electrical wires. The plunger is configured to attach to a derrick man. The plunger and the receptacle are configured to mate when the plunger is inserted into the receptacle and to remain frictionally mated until pulled apart. The mating results in closing the circuit between the pair of electrical wires.
In another aspect, some configurations of the present invention provide a safety apparatus that includes a quick-disconnect switch. The quick-disconnect switch has at least a first part attachable to a derrick man and a second part located on a drill pipe stand near a piece of safety protection equipment. The quick-disconnect switch is operable by a derrick man to indicate that he or she is in position and protected by the piece of safety protection equipment. A light panel in electrical communication with the quick-disconnect switch is also provided. The light panel is located in a position visible by a driller located under the drill pipe stand and is configured to indicate when the quick-disconnect switch is open or closed by the derrick man.
In yet another aspect, some configurations of the present invention provide a safety apparatus on an oil derrick. The safety apparatus includes a plurality of radio frequency identification (RFJD) tags. Each RPID tag assigned to crew members on the oil derrick. Also provided is a plurality of sensors and/or antennae located on the oil derrick that are configured to track and report the location of each said RFID tag. In addition, a control panel having at least one indicator is provided. The control panel is responsive to the location reports and the indicator or indicators are configured to indicate, to a driller, when needed crew members are present and in locations in which the crew members are supposed to be for an operation of the oil derrick being undertaken.
It will be appreciated that some configurations of the present invention provide a comprehensive approach to monitoring crew behavior and location. It will also be appreciated that some configurations of the present invention provide apparatus to make drilling operations safer, and/or that assist in changing the behavior of personnel to make safety systems more effective.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial view of a quick-disconnect switch embodiment.
FIG. 2 is a close-up pictorial view of the reduced diameter male portion of the switch plunger shown in FIG. 1 .
FIG. 3 is an axial cut-away view of the quick-disconnect switch of FIG. 1 .
FIG. 4 is a pictorial view into the female portion of the switch receptacle shown in FIG. 1 .
FIG. 5 is a pictorial view into the reduced diameter male portion of the switch plunger shown in FIGS. 1 and 2 .
FIG. 6 is a pictorial view of the quick-disconnect switch of FIG. 1 attached to a safety vest on a derrick man. Also shown is a hard hat carrying a radio frequency identification (RFIO) tag.
FIG. 7 is a pictorial view of a portion of an oil derrick on which the derrick man is located while working.
FIG. 8 is a close up pictorial view of the location at which the derrick man works on the oil derrick of FIG. 7 .
FIG. 9 is a pictorial view of the bottom portion of the oil derrick of FIG. 7 , showing a light panel inside a driller's shelter.
FIG. 10 is a pictorial schematic diagram of an embodiment of a safety protection system of the present invention.
The foregoing summary, as well as the following detailed description of certain embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. To the extent that the figures illustrate diagrams of the functional blocks of various embodiments, the functional blocks are not necessarily indicative of the division between hardware circuitry.
DETAILED DESCRIPTION OF THE INVENTION
As used herein, an element or step recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural said elements or steps, unless such exclusion is explicitly stated. Furthermore, references to “one embodiment” of the present invention are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.
Moreover, unless explicitly stated to the contrary, embodiments “comprising” or “having” an element or a plurality of elements having a particular property may include additional such elements not having that property.
Referring now to FIG. 1 , some configurations of the present invention provide a quick-disconnect switch 10 that comprises two generally cylindrical components, namely a plunger 12 and a receptacle 14 . In some embodiments, plunger 12 includes a lateral hole 16 near an outside end 17 of plunger 12 . Hole 16 is provided as an attachment point to allow a strap or loop to enter for attachment of switch 10 to a harness or other item of clothing (not shown in FIG. 1 ).
Receptacle 14 includes a first portion comprising a cap 22 having two wires passing therethrough. In FIG. 1 , these two wires are enclosed in a sheath or plastic tube 19 . Receptacle 14 also has a second, female portion 24 that mates with a reduced diameter, male portion 64 of plunger 12 . To provide a watertight as well as frictional fit, at least one, and in the illustrated embodiment two, rubber O-rings 58 and 60 are fitted into grooves in male portion 64 of plunger 12 . 0-rings 58 and 60 are seen to best advantage in FIG. 2 . In some embodiments, 0-rings 58 and 60 may also act to resist the accidental separation of plunger 12 from receptacle 14 due to an air seal formed by the O-rings.
In some embodiments and referring to FIG. 3 , a female portion 24 of receptacle 14 has two hollow insulators 26 and 28 passing in an axial direction therethrough. Widened rims 42 and 44 and round fasteners 38 and 40 hold hollow insulators 26 and 28 in place. respectively. Threaded conducting rods 34 and 36 pass internally through insulators 26 and 28 , respectively, and are directly connected to wires 18 and 20 , respectively, using tightened nuts 30 and 32 , respectively. Wires 18 and 20 , when not electrically connected, are an open circuit pair of wires. An opposite end of rods 34 and 36 form electrical contacts or posts 46 and 48 , respectively. Posts 46 and 48 project a slight distance above an internal floor of a hollow portion 62 of receptacle 14 as can readily be seen in the pictorial view of FIG. 4 .
Referring again to FIG. 3 , plunger 12 includes a reduced diameter portion 64 and a full diameter portion 66 . In some embodiments, full diameter portion 66 has the same outside diameter as that of receptacle 14 . Reduced diameter portion 64 is configured to tightly, yet slidingly engage hollow portion 62 of receptacle 14 . A post 50 is embedded in an axis of cylindrical plunger 12 . An e-clip 68 on post 50 holds a retainer 56 against a wall in a hollowed-out portion of plunger 12 . A resilient spongy or compressible disk 54 through which post 50 passes is affixed on one side to a face of retainer 56 facing towards posts 46 and 48 , with a conductive, flat annulus 52 affixed to the other side of disk 54 . Annulus 52 is best seen in the pictorial view of FIG. 5 . Preferably, conductive, flat annulus 52 comprises a flexible, but resilient, metallic sheet. Together (or separately, in some embodiments), disk 54 and annulus 52 are biased towards posts or terminals 46 and 48 to eliminate the need for posts 46 and 48 to be precisely the same length. One or more a-lings 58 and 60 are seated in grooves around reduced diameter portion 64 of plunger 12 and provide some frictional resistance to the separation of plunger 12 from receptacle 14 or a relatively air-tight seal to provide such resistance, or both. The frictional resistance prevents plunger 12 and receptacle 14 from simply sliding apart, but allows separation to occur easily when plunger 12 and receptacle 14 are pulled apart, either deliberately or when a force pulls on the lanyard or strap through hole 16 .
In some embodiments and referring again to FIG. 3 , when plunger 12 is inserted into receptacle 14 , electrical contact is completed between posts 46 and 48 through conductive, flat annulus 52 . Thus, there is a completed electrical path between wires 18 and 20 in this condition. When plunger 12 is pulled from receptacle 14 , this path is broken, and there is no complete electrical path between wires 18 and 20 . Thus, when a lanyard or strap is attached to plunger 12 through hole 16 and wires 18 and 20 are electrically communicating with an alarm system, quick-disconnect switch 10 can be used to indicate an alarm condition by the separation of plunger 12 from receptacle 14 .
In one embodiment, quick disconnect switch 10 has a diameter of about 27 mm and FIG. 3 , for this embodiment, is drawn approximately to scale. However, neither the diameter nor the length of quick disconnect switch 10 are critical elements of the present invention. In particular, FIG. 3 does not necessarily represent either the diameter or the relative dimensions of components of quick disconnect switch in all embodiments of the invention. The dimensions of any particular quick disconnect switch may be left as a design choice to one of ordinary skill in the art upon obtaining an understanding of the present invention from this description and the accompanying drawings.
In one configuration of the present invention and referring to FIG. 6 , quick disconnect switch 10 is attached by a lanyard 102 to a safety vest 104 worn by a derrick man 106 or other worker. Lanyard is threaded through hole 16 in plunger 12 . Receptacle 14 attaches via wires 18 and 20 to electrical equipment not shown in FIG. 2 . In some embodiments, receptacle 14 is tethered in place to the electrical equipment by wires 18 and 20 . When derrick man 106 arrives at a job site, he or she puts on vest 104 (which has lanyard 102 and plunger 12 attached thereto) and inserts plunger 12 into receptacle 14 to provide a “safe” indication to the electrical equipment. When derrick man 106 wants to indicate an “unsafe” condition, he or she pulls plunger 12 from receptacle 14 . In another embodiment, if the worker is pulled, pushed, or otherwise displaced from a safe position, plunger 12 is pulled out of receptacle 14 without further intervention by derrick man 106 by movement of safety vest 104 and lanyard 102 .
In some embodiments and referring to FIGS. 7, 8 and 9 , derrick man 106 is located on an oil drilling rig 200 . Drilling rig 200 works on a drill pipe stand 202 that has a finger board 204 that keeps drill pipe stands 202 separated. Drill pipe stand 202 also has a racking board 214 that is used to rack stands of drill pipe when worker 106 is making a trip to change a drill bit or to install a different drilling tool. The racking board is usually about 24 to 30 meters above the floor, as indicated by bracket 206 . On most drilling rigs 200 , derrick man 106 climbs up a ladder 208 to reach racking board 214 to enter an open or “working” side 212 of derrick 200 . A traveling block 210 is used to pull pipe out of a well and return it to the floor of drilling rig 200 .
Derrick man 106 works on racking board 214 when the rig is “tripping” pipe into or out of a well. He is constantly walking from the outside or back of racking board 214 to the open or working side 212 of derrick 200 . In some embodiments, a block 216 (such as a DBI/SALA® brand fall protection device, available from D B Industries, Inc., Red Wing, Minn.) is used to provide a measure of protection for derrick man 106 when he is climbing derrick 200 . Once at racking board 214 , derrick man 106 transfers himself to another block (not shown in the Figures) attached to the top of derrick 200 .
Once derrick man 106 is in position, he engages switch 10 (not shown in FIG. 7, 8 or 9 ), which is wired to a light panel 220 below in driller's shelter 218 . This engagement completes an electrical circuit that provides a visual indication on light panel 220 to the driller that derrick man 106 has attached the appropriate block 216 to his harness and is ready to resume operations.
Sometimes due to a stop in running the pipe, derrick man 106 may unhook or sit and wait for operations to resume. With switch 10 disengaged, the driller knows not to raise the traveling block 216 (lifting or lowering the drill string) until derrick man 106 confirms through light panel 220 that he is hooked up to his fall protection. In some embodiments, switch 10 can also (or alternately) be used to signal equipment for automatic cut-off. Also, in some embodiments, an alarm or light remains actuated until switch 10 is reengaged.
In some embodiments of the present invention, a horn (not shown in the drawings) is provided in addition to light panel 220 , and engagement of switch 10 also (at least momentarily) sounds the horn as a signal to the driller.
In some embodiments of the invention, switch 10 is designed for rugged conditions, and is shock-resistant, water-tight, and/or corrosion resistant. For example, the cylindrical metallic parts of switch 10 may comprise anodized aluminum, and rubber O-tings 58 and 60 provide a water-tight seal.
In some embodiments of the invention, switch 10 comprises a two-piece unit having a plunger 12 and a receptacle 14 . Receptacle 14 is attached to rig 200 at an appropriate location and plunger 12 is attached to derrick man 106 . When plunger 12 and receptacle 14 are joined together, a switch is tripped and a circuit is completed. The signal generated by the completed circuit is used to alert the driller that derrick man 106 is properly harnessed and prepared to begin rig operations.
In some embodiments, receptacle 14 and plunger 12 are held together by friction. When plunger 12 is properly inserted into receptacle 14 , an electrical contact is made within switch 10 and a circuit completed. Plunger 12 and receptacle 14 are each anchored to its respective piece of the safety harness system with enough lead to permit plunger 12 and receptacle 14 to be joined together only when the safety equipment is properly in place. In one embodiment, the completed circuit (or a relay or electronic switch controlled thereby) turns a red light on light panel 220 to green, thereby letting the chiller know that the derrick man is ready for operations. If the derrick man removes his safety harness, plunger 12 is necessarily removed from receptacle 14 , breaking the circuit and changing the green light to red.
In some embodiments of the present invention and referring to the block schematic drawing of safety system 400 of FIG. 10 , various crew members 402 are required to be in different locations around rig 200 . In these embodiments, proximity technology is combined with switch 10 to relay information to driller 408 regarding the location of each crew member 402 , which may also include derrick man 106 . When the responsible crew member 402 is where he or she is supposed to be for the operation being undertaken, driller 408 is notified by a signal, such as a red light 410 turning green on panel 220 . Only when all lights 410 are green would the driller 408 begin rig operations.
For example, and referring to FIGS. 6 and 10 , a radio frequency identification (RFID) tag 302 is assigned to each crew member 402 (which may, but need not necessarily include derrick man 106 ). RFID technology is suitable for this purpose because it can be used in harsh environments and tuned for distance. Either active or passive RFID tags 302 are suitable. The use of RFID tags 302 permits data acquired to be passed to databases 416 that can record histories and/or determine safe or unsafe conditions by comparing the location of each crew member 402 to a database of predetermined locations. The predetermined conditions can be modified to take account of rig configuration, size of crew, operation being undertaken, individual company safety policies, and/or any other factors as may be appropriate.
RFID tag 302 is, in some embodiments, embedded in a hard hat 300 . In other embodiments, RFID tag 302 is embedded in another device associated with an individual crew member 402 . For example, RFID 302 may be worn inside clothing like “dog tags” or incorporated into other safety gear. Sensors 404 with wireless antennae 406 are located around rig 200 can constantly track and report the location of each RFID 302 signal associated with a crew member 402 , and each RFID 302 may be separately identified with an individual crew member 402 . Data from sensors 404 are transmitted via antennae 406 to a receiver comprising an antenna 412 and a modem 414 . Data from modem 414 is fed to control panel 220 either directly or indirectly, where it is used by driller 408 to determine the location of the crew members 402 . Control panel 220 , for example, may display a light 410 when a crew member 402 is present at his assigned location, or additional electronic control logic and/or databases 416 can be provided in or associated with control panel 220 to compare the crew members 402 present and their locations with a predetermined set of parameters to advise driller 408 whether the needed personnel were present and in the location in which they were supposed to be for the operation being undertaken. In some embodiments of the present invention, derrick man 106 uses an RFID tag 302 either to supplement or to substitute for switch 10 , although in most embodiments, it is envisioned that derrick man 106 would use switch 10 and no RPID tag, at least in part because of his location.
It will be appreciated that some configurations of the present invention provide a comprehensive approach to monitoring crew behavior and location. It will also be appreciated that some configurations of the present invention provide apparatus to make drilling operations safer, and/or that assist in changing the behavior of personnel to make safety systems more effective.
While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims. | A safety apparatus for personnel on an oil drilling rig includes a cylindrical quick disconnect switch having a receptacle and a plunger. The receptacle has an open circuit pair of electrical wires. The plunger is configured to attach to a derrick man. The plunger and the receptacle are configured to mate when the plunger is inserted into the receptacle and to remain frictionally mated until pulled apart. The mating results in closing the circuit between the pair of electrical wires. | 4 |
BACKGROUND OF THE INVENTION
Polysiloxane polyols are well known in the art. Japanese Patent Publication 48-19941 describes polysiloxane polyols which are obtained by the dehydrogenation reaction between a polysiloxane hydride and an aliphatic polyhydric alcohol or polyoxyalkylene alcohol to introduce the alcoholic hydroxy groups onto the polysiloxane backbone. In practice, however, it is difficult to obtain an industrially significant yield of such polysiloxane polyols because such a dehydrogenation reaction readily gels. Another problem encountered with this dehydrogenation reaction is the difficulty in obtaining a solvent capable of dissolving both reactants. Strongly hydrophilic alcohols such as polyglycerols are highly soluble in alcohols and water, but insoluble in hydrocarbon solvents. Polysiloxanes, however, are generally only soluble in hydrocarbon solvents such as toluene or n-hexane.
U.S. Pat. No. 4,431,789 to Okszaki et al. discloses a polysiloxane polyol which is obtained by the hydrosilylation reaction between a polysiloxane containing silicon hydride and a polyglycerol compound having an aliphatically unsaturated linkage in the molecule. Examples of such polyglycerol compounds are those obtained by the reaction of allyl alcohol and glycidol or by the reaction of diglycerin and allyl glycidyl ether. This reaction, a so-called hydrosilylation reaction, is the addition reaction between an organosilicon compound having a hydrogen atom directly bonded to the silicon atom, i.e., a polysiloxane hydride, and an organic compound having aliphatic unsaturation in the molecule carried out in the presence of a catalytic amount of a Group VIII noble metal. The hydrosilylation reaction can proceed readily in the presence of an alcoholic solvent which can dissolve both reactants. The resulting polysiloxane polyols are useful as non-ionic surface active agents.
U.S. Pat. No. 5,260,469 discloses butoxylated polysiloxane polyols which are disclosed as being useful in cosmetics.
Also known in the art are acetoacetate functional acrylic crosslinking polymers. U.S. Pat. No. 4,408,018 to Bartnan et al. describes the introduction of pendant acetoacetate functional moieties onto an acrylic polymer backbone for crosslinking with alpha, beta-unsaturated esters via the Michael addition reaction. The acetoacetate functional acrylic polymers may be prepared in either of two ways. An acetoacetic ester of a hydroxyl group containing acrylic monomer, such as hydroxyethyl methacrylate or hydroxyethyl acrylate, can be produced by the transacetylation of the hydroxyl containing acrylic monomer with an acetoacetate. These acetylated monomers can then be copolymerized with other polymerizable monomers to introduce the acetoacetate moiety into the acrylic polymer chain. Alternatively, an acrylic polymer chain having hydroxyl functionality thereon can be transesterified with an alkyl acetoacetate to introduce the acetoacetate moiety into the acrylic polymer backbone. The references also disclose the acetoacetylation of the hydroxyl groups of a polyester polyol to yield an acetoacetate containing polyester.
SUMMARY OF THE INVENTION
The present invention relates to novel functional polysiloxanes and a method for the preparation of such polysiloxanes. Also disclosed is a curable coating composition containing the functional polysiloxanes.
The curable coating composition containing the functional polysiloxane is readily curable at ambient temperatures and produces a cured film with excellent performance properties such as cure speed, low VOC, excellent humidity resistance, flexibility and adhesion over galvanized steel.
The functional polysiloxane having the general structural formula: ##STR1## wherein the group represented by R a contains a group having the general structure: ##STR2## where the R groups are selected from the group consisting of OH and monovalent hydrocarbon groups connected to the silicon atoms, m is at least one; m' is 0 to 50, and n is 0 to 50. Preferably, the group R a contains a group having the general structure: ##STR3## where X is NH, O or S.
The preparation of the functional polysiloxane of structural formula (I) comprises:
(a) hydrosilylating a polysiloxane containing silicon hydride, where the ratio of hydrosilylated silicon atoms to non-hydrosilylated silicon atoms is at least 0.1:1, and preferably 0.1 to 10:1, with an alcohol, primary or secondary amine, or thiol containing vinyl or vinylidene groups which are capable of hydrosilylating said polysiloxane containing silicon hydride, to yield a polysiloxane containing hydroxyl, amine or thiol groups or mixtures thereof; and
(b) esterifying the hydrosilylated reaction product of (a) with the acetoacetate to produce the acetoacetate functional polysiloxane.
The curable coating composition comprises:
(a) a functional polysiloxane having the general formula (II) or (III) wherein at least one of the groups represented by R a contains a group having the general structural formula (I) or (IV), where n is 0 to 50; m is at least one; m' is 0 to 50; and in the case of structural formula (I), X is NH, O or S; and the other R groups are selected from the group consisting of OH and monovalent hydrocarbon groups bonded to the silicon atoms; and
(b) a polyamine or a blocked polyamine. In the preferred embodiment of the invention, X is O. Optionally, the curable coating composition of the invention further comprises a polyacrylate curing agent.
The coated substrates have thereon a film comprising the cured reaction product of the following reactants:
(a) a functional polysiloxane having general structural formula (II) or (III) wherein at least one R a group contains a group represented by the structural formula (I) or (IV), where n is 0 to 50; m is at least one; m' is 0 to 50; and in the case of structural formula (I), X is NH, O or S; and the R groups are selected from the group consisting of H, OH and monovalent hydrocarbon groups; and
(b) a polyamine or a blocked polyamine.
In the preferred embodiment of the invention, X is O. Optionally, the coated substrate may have a film thereon further comprising as one of the reactants a polyacrylate curing agent.
DETAILED DESCRIPTION OF THE INVENTION
The finctional polysiloxane of the present invention has the general formula (II) or (III) wherein at least one of the groups represented by R a contains a group having the general structure (I) or (IV) and in the case of (I) where X is --N, O or S, preferably O; the R groups are selected from the group consisting of OH and monovalent hydrocarbon groups bonded to the silicon atoms; and m is at least one; m' is 0 to 50; n is 0 to 50, preferably 0 to 35, and more preferably 2 to 15. By monovalent hydrocarbon groups is meant organic groups containing essentially carbon and hydrogen. The hydrocarbon groups may be aliphatic, aromatic, cyclic or acyclic and may contain from 1 to 24 (in the case of aromatic from 3 to 24) carbon atoms. Optionally, the hydrocarbon groups may be substituted with heteroatoms, typically oxygen. Examples of such monovalent hydrocarbon groups are alkyl, alkoxy, aryl, alkaryl or alkoxyaryl groups.
Preferably the functional polysiloxane has an equivalent weight of 100 to 1500, more preferably from 150 to 500 (grams/equivalent) based upon the equivalents of acetoacetate.
At least one of the groups represented by R a typically contains a group of the following general structure: ##STR4## where L is an organic linking group and x is 1 to 3. Preferably L is alkylene, oxyalkylene or alkylene aryl. By alkylene is meant acyclic or cyclic alkylene groups having a carbon chain length of from C 2 to C 25 . Examples of suitable alkylene groups are those derived from propene, butene, pentene, 1-decene, isoprene, myrcene and 1-heneicosene. By oxyalkylene is meant an alkylene group containing at least one ether oxygen atom and having a carbon chain length of from C 2 to C 25 , preferably of from C 2 to C 4 . Examples of suitable oxyalkylene groups are those associated with trimethylolpropane monoallylether, trimethylolpropane diallylether and ethoxylated allylether. By alkylene aryl is meant an acyclic alkylene group containing at least one aryl group, preferably phenyl, and having an alkylene carbon chain length of from C 2 to C 25 . The aryl group may optionally be substituted. Suitable substituent groups may include hydroxyl, benzyl, carboxylic acid and aliphatic groups. Examples of suitable alkylene aryl groups include styrene and 3-isopropenyl-α, α-imethylbenzyl isocyanate.
Preferably the functional polysiloxane of the present invention is an acetoacetate functional polysiloxane and has the following general structural formula: ##STR5## where m is at least one; m' is 0 to 50; n is 0 to 50; R is selected from the group consisting of OH and monovalent hydrocarbon groups connected to the silicon atoms; and at least a portion of R b groups has the following structure: ##STR6## wherein R 1 is alkylene, oxyalkylene or alkylene aryl; and R 2 is alkylene, oxyalkylene or alkylene aryl, and z is one to 3 and where Y is selected from the group consisting of alkyl, Cl, Br, I and OR', preferably where R' is C 1 to C 12 alky. When only a portion of the hydroxyl groups of the polysiloxane polyol produced in the hydrosilylation step are esterified, the remaining R b groups are:
L--OH and/or R 1 --O-R 2 --OH where L, R 1 and R 2 are as defined above.
Preferably, the ratio of m:n in the acetoacetate functional polysiloxane of structure (IV) is at least 0.1:1, preferably 0.1 to 10:1. Ratios less than 0.1 to 1 are not preferred because these materials are typically not compatible with organic materials (i.e., resins and solvents).
A method of preparing the acetoacetate functional polysiloxane of the present invention comprises
(a) hydrosilylating a polysiloxane containing silicon hydride such as one having the structure: ##STR7## wherein the R groups are selected from the group consisting of OH and monovalent hydrocarbon groups connected to the silicon atoms; n is 0 to 50; m is at least one; and m' is 0 to 50, such that the ratio of hydrogen-bonded silicon atoms to non-hydrogen-bonded silicon atoms is at least 0.1:1, preferably from 0.1 to 10:1; with an alcohol, primary or secondary amine, or thiol containing vinyl or vinylidene groups which are capable of hydrosilylating said polysiloxane containing silicon hydride, to produce a polysiloxane containing hydroxyl, amine or thiol groups or mixtures thereof; and
(b) esterifying the hydrosilylated reaction product of (a) with an acetoacetate such as one having the structure: ##STR8## where Y' is selected from the group consisting of Cl, Br, I and OR', preferably OR', where R' is C 1 to C 12 alkyl, to produce an acetoacetate functional polysiloxane.
Alternatively, the esterification can be conducted with the alcohol before the hydrosilylation step.
Preferably n is from about 0 to 50, more preferably from about 0 to 35, and even more preferably from 2 to 15. Examples of the polysiloxane containing silicon hydride are 1,1,3,3-tetramethyl disiloxane and polysiloxane containing silicon hydrides where n is 4 to 5, commercially available from PPG Industries, Inc. as MASILWAX BASE.
It is preferred that the polysiloxane containing silicon hydride is hydrosilylated with an alkenyl alcohol, preferably an allylic polyoxyalkylene alcohol. Examples of suitable alkenyl alcohols are allylic polyoxyalkylene alcohols and include polyethoxylated allylic alcohol, trimethylolpropane monoallylether and polypropoxylated allyl alcohol. In the most preferred embodiment of the invention, the alkenyl alcohol is trimethylolpropane monoallylether.
Typically the preparation of the acetoacetate functional polysiloxane is carried out in two steps: (1) a hydrosilylation step and (2) an esterification step. In step 1, the alcohol, primary or secondary amine, or thiol is added at ambient temperature to a reaction vessel equipped with a means for maintaining a nitrogen blanket. Added concurrently is about from 20 to 75 ppm sodium bicarbonate or metal acetate salt to inhibit the possible undesirable side reactions such as those associated with acetal condensation via a propenyl ether moiety. The temperature is increased to 75° C. under a nitrogen blanket at which time about 5% of the polysiloxane containing silicon hydride is added under agitation. A catalyst such as a transition metal, for example, nickel, nickel compounds and iridium salts, preferably chloroplatinic acid, is then added and the reaction is permitted to exotherm to 95° C. Addition of the remaining portion of the polysiloxane containing silicon hydride is completed as the reaction temperature is maintained at 80-85° C. The reaction is monitored by infrared spectroscopy for disappearance of the silicon hydride absorption band (Si--H: 2150 cm -1 ).
To this product is added the acetoacetate and the temperature is increased to 120° C. under a nitrogen sparge. During heating, the evolving alcohol is collected. Complete distillation provides the acetoacetate functional polysiloxane of the present invention.
The curable coating composition of the present invention comprises (a) a functional polysiloxane of the structural formula (II) or (III) wherein at least one of the groups represented by R a contains a group having the general structural formula (IV) or (I), where n, m, m', R and X are as defined above for formulae (II) and (III); and (b) a polyamine or blocked polyamine. Preferably the functional polysiloxane has the general structural formula (VII) or (VIII) where n, m, m', z, R 1 , R 2 , R b and Y are all as defined above for formula (VI), (VII), (VIII) and (IX).
Preferably, the blocked polyamine is a polyketimine having the structure: ##STR9## where p is 0 to 6; R 3 and R 4 are the same or different and are alkylene, oxyalkylene, or alkylene aryl; and the R 5 ' and the R 5 " groups are independently H or alkyl containing from 2 to 20 carbon atoms, preferably 2 to 6 carbon atoms; or aryl containing from 6 to 24 carbon atoms; are each substantially inert to the ketimine formation reaction; and R 5 ' and R 5 " together can form part of a 3,4,5, or 6 membered ring.
Besides ketimines, aldemines can also be used and unless otherwise indicated, ketimines and polyketimines is meant to include aldemines and polyaldemines. Preferably the polyketimine is the reaction product of a polyepoxide with a ketimine containing secondary amine group. The polyepoxide can be selected from materials which contain at least two oxirane groups in the molecule. An oxirane group may be represented by the general structural formula: ##STR10## where q is at least two; R 7 is H or CH 3 ; and R 8 broadly represents an organic based molecule or polymer typically composed of carbon, hydrogen, oxygen, and optionally nitrogen and/or sulfur. Hydroxyl substituent groups can also be present and frequently are, as well as halogen and ether groups. Generally the epoxide equivalent weight ranges from about 100 to about 1000, preferably from about 100 to about 500, and more preferably from about 150 to about 250. These polyepoxides can be broadly categorized as being aliphatic, aromatic, cyclic, acyclic, alicyclic or heterocyclic.
One particularly preferred group of polyepoxides for use in the present invention are the epoxy novalac resins which are prepared by reacting an epihalohydrin with the condensation product of an aldehyde with a monohydric or polyhydric phenol. One example is the reaction product of epichlorohydrin with a phenolformaldehyde condensate.
Another particularly preferred group of polyepoxides are the polyglycidyl ethers of polyhydric aromatic alcohols, which are prepared by reacting an epihalohydrin, such as epichlorohydrin, with a polyhydric aromatic alcohol. Suitable examples of dihydric phenols include resorcinol, catechol, hydroquinone, bis(4-hydroxyphenyl)-1,1-isobutane; 4,4-dihydroxybenzophenone; bis(4-hydroxyphenyl)-1,1-ethane; bis(2-hydroxynaphenyl)methane; 1,5-hydroxynaphthalene and 4,4'-isopropylidenediphenol, i.e., Bisphenol A. Bisphenol A is preferred.
It should be understood that mixtures of polyepoxides may also be utilized in the present invention.
A specific example of a polyepoxide-ketimine reaction product involves reacting a polyamine such as one mole of diethylenetriamine with two moles of methylisobutyl ketone to produce a diketimine with secondary amine functionality. Alternatively, an aldehyde such as isobutylaldehyde or benzaldehyde can be used in place of or in conjunction with the ketone to form an aldimine. This ketimine, or aldimine, is then reacted with a polyepoxide, depleting effectively all of the oxirane groups of the polyepoxide and resulting in a ketimine or aldimine which is essentially free of all oxirane groups. By "essentially free of oxirane groups" is meant that the epoxy equivalent weight of the reaction product is measured to be about at least 5000 (grams/equivalents), on average the reaction product contains less than 1, more preferably, on average, less than 0.5 oxirane groups per molecule.
Representative of the polyamines which may be utilized in the present invention are aliphatic or cycloaliphatic amines having from 2 to 200 carbon atoms and from 2 to 10 primary and/or secondary amino groups, preferably from 2 to 4 primary amino groups. Examples of suitable polyamines include ethylenediamine, propylenediamine, butylenediamine, pentamethylenediamine, hexamethylenediamine; decamethylenediamine; 4,7-dioxadecane-1,10-diamine; dodecamethylenediamine; 4,9-dioxadodecane-1,12-diamine; 7-methyl-4,10-dioxatridecane-1,13-diamine; 1,2-diaminocyclohexane; 1,4-diaminocyclohexane; 4,4'-diaminodicyclohexyl methane; isophorone diamine; bis(3-methyl-4-aminocyclohexyl)methane; 2,2-bis(4-aminocyclohexyl)propane; nitrile tris(ethane amine); bis(3-aminopropyl) methylamine; 2-amino-1-(methylamino)propane; 3-amino-1-(cyclohexylamino)propane; and N-(2-hydroxyethyl)ethylene diamine.
A particularly preferred group of polyamines that are useful in the practice of the present invention can be represented by the following structural formula:
H.sub.2 N--(--R.sub.3 --NH).sub.p --R.sub.4 --NH.sub.2 (XV)
where the R 3 and R 4 can be the same or different and represent an alkylene, oxyalkylene or alkylene aryl group containing from 2 to 20 and preferably from 2 to 10 carbon atoms and p is from about 1 to 6, preferably from about 1 to 3. Nonlimiting examples of polyalkylene polyamines suitable for use in the present invention include diethylenetriamine, dipropylenetriamine and dibutylenetriamine.
The aldehyde or ketone which is reacted with the polyamine can be represented by the following structural formula: ##STR11## wherein R 5 and R' 5 are independently H, C 2 to C 20 alkyl or C 6 to C 24 aryl, and R 5 and R' 5 together can form part of a 3, 4, 5, or 6 membered ring. Examples of suitable aldehydes and ketones for use in the present invention as modifiers or blocking agents for the amine groups include, acetone, diethyl ketone, methylisobutyl ketone, diisobutyl ketone, isobutyraldehyde, hydroxybutyraldehyde, benzaldehyde, salicylaldehyde, pentanone, cyclohexanone, methylamyl ketone, ethylamyl ketone, hydroxycitronellal, isophorone and decanone. Ketones preferred for use in the present invention include acetone, diethyl ketone, diisobutyl ketone, pentanone, cyclohexanone, methylamyl ketone, isophorone, decanone and methylisobutyl ketone and methylphenyl ketone.
In one preferred embodiment of the present invention, the polyketimine is essentially free of oxirane functionality; has an average of at least two ketimine groups per molecule, preferably an average of about from 2 to about 25 ketimine groups per molecule, and more preferably of from about 3 to about 6 ketimine groups per molecule; and has a weight average molecular weight of from about 1000 to 50,000, preferably of from about 1000 to about 10,000, and more preferably of from about 1000 to about 5000, as determined by gel permeation chromatography (GPC) using a polystyrene standard.
Polyamines can also be used as component (b) in the curable composition. Examples of such polyamines are those described above.
Optionally, the curable coating composition of the present invention can contain a polyacrylate functional component. The preferred polyacrylate functional component contains at least two acryloyl groups or methacryloyl groups per molecule. Suitable polyacrylate functional components include the esterification or transesterification reaction products of acrylate or methacrylate containing materials, such as acrylic or methacrylic acids or acrylic or methacrylic esters as described in more detail below, with di-, tri- or polyvalent polyols, including polyester polyols and polyether polyols; and the reaction product of a hydroxyl group containing acrylate or methacrylate with a polyisocyanate.
The polyol used in the transesterification reaction is typically a low molecular weight diol, triol or tetrol. These polyols generally have a formula molecular weight ranging from about 50 to about 1000, and preferably from about 100 to about 500. Examples of suitable polyols include ethylene glycol, propylene glycol, diethylene glycol, tetramethylene diol, neopentyl glycol, hexamethylene diol, 1,6-hexanediol, cyclohexane diol, bis-(4-hydroxycyclohexyl) methane, glycerol, trimethylolethane, trimethylolpropane, tris(2-hydroxyethyl)-isocyanurate, pentaerythritol and ethoxylated Bisphenol A. Preferably a diol such as ethoxylated Bisphenol is used. It should be understood, however, that if desired, higher molecular weight polyols such as oligomeric or polymeric polyols can be utilized to prepare the polyacrylate containing material.
As aforementioned, the polyacrylate functional material may also be the reaction product of a polyisocyanate and a hydroxyl group containing acrylate or methacrylate. The polyisocyanate is typically a low molecular weight diisocyanate or triisocyanate having a formula weight of from about 200 to 1000, and preferably from about 200 to 600. Examples of suitable polyisocyanate materials include toluenediisocyanate, 4,4'-diphenylmethanediisocyanate, isophoronediisocyanate, tris(toluenediisocyanate)trimethylolpropane, 1,6-hexamethylenediisocyanate, 1,4-tetramethylenediisocyanate and 4,4'-methylenebis(cyclohexyl isocyanate). It should be understood, however, that if desired, higher molecular weight polyisocyanates, such as oligomeric or polymeric materials can be utilized to prepare the polyacrylate functional material.
The acrylate or methacrylate containing material, which is reacted either with the above-mentioned polyol or polyisocyanate to produce the polyacrylate functional material, can be represented by the general structural formula: ##STR12## where R 9 is H or CH 3 , and R 10 is H, alkyl containing from one to 20 carbons, or hydroxy alkyl containing from 1 to 20 carbons. Nonlimiting examples of suitable acrylate or methacrylate containing materials include acrylic acid, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-hydroxyethyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, hexyl acrylate and 2-hydroxyethyl acrylate.
The polyacrylate functional materials used in the present invention generally have a weight average molecular weight of from about 100 to about 50,000 as determined by GPC using a polystyrene standard. In the preferred embodiment of the present invention, the polyacrylate functional materials are low molecular weight materials which have a formula weight generally from about 100 to about 5000, and more preferably from about 100 to about 500.
Examples of suitable polyacrylate functional materials include 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, ethoxylated bisphenol A diacrylate and tris(2-hydroxyethyl)isocyanurate triacrylate.
Although not intending to be bound by any theory, it is believed that the functional polysiloxane and the polyacrylate functional material, if present, react with the polyketimine to cure the claimed coating compositions. The reaction is believed to proceed by the deblocking of ketones from the polyketimine which exposes the primary amines which are believed to subsequently react with the acetoacetate functional polysiloxane and, if present, the polyacrylate functional material.
Optionally, an effective amount of acid catalyst can be used to accelerate the cure. Examples of appropriate acid catalysts include stearic acid, isostearic acid, undecylenic acid and phosphoric acid. It should be understood that any organic or inorganic acid could serve as a catalyst, but it is preferred that the acid be monofunctional. If used, the acid is generally present in minor amounts, typically from about 0.1 to about 1.0 percent by weight, the percentage based on total weight of resin solids.
It is preferred that the curable coating composition of the present invention be essentially free of strong base. By "strong base" is meant that the pK b of the base is greater than or equal to 11. By "essentially free of strong base" is meant that no more than 1 percent by weight, the percentage based on total weight of resin solids, is present in the composition. The presence of a strong base is believed to catalyze Michael addition between the acetoacetate functional polysiloxane and, if present in the composition, the polyacrylate functional material. (See Clemens et al., "A Comparison of Catalysts for Crosslinking Acetoacetylated Resins via the Michael Reaction", Journal of Coatings Technology, Vol. 61, No. 770, March 1989) Cure by this Michael reaction is not desirable since it has been observed to result in unacceptably reduced pot-life of the coating composition.
The curable coating compositions of the invention can be pigmented or unpigmented. Suitable pigments for color coats include opaque, transparent and translucent pigments generally known for use in coating applications. Examples include titanium dioxide, zinc oxide, antimony oxide, iron oxide, carbon black and phthalocyanine blue. Metallic pigments such as aluminum flake and metal oxide-coated micas can also be used. The coatings may also contain extender pigments such as calcium carbonate, clay, silica, talc, etc. When pigment is used, it typically present in the composition in amounts such that the pigment to binder ratio is from about 0.03 to 6.0:1.
In addition to the foregoing components, the coating compositions of the invention may include one or more optional ingredients such as plasticizers, anti-oxidants, light stabilizers, mildewcides and fungicides, surfactants and flow control additives or catalysts as are well known in the art.
The components present in the curable coating composition of the present invention generally are dissolved or dispersed in an organic solvent. Organic solvents which may be used include, for example, alcohols, ketones, aromatic hydrocarbons, esters or mixtures thereof. Specific examples include ethanol, acetone, methyl ethyl ketone, methyl amyl ketone, xylenes and butyl acetate. Typically, organic solvent is present in amounts of 5 to 80 percent by weight based on total weight of the composition.
The coating compositions of the invention are particularly useful as topcoats and particularly as primers. Because of their low temperature curing properties, they are particularly suitable for use in automotive refinish applications. Once the functional polysiloxane component and the polyamine or blocked polyamine component come into contact with each other, the coating composition will begin to cure at ambient conditions. Accordingly, it is desirable to prepare the compositions in the form of a two-package system with the polyamine or blocked polyamine component in one package and the functional polysiloxane component and, optionally, the polyacrylate functional material in a second package.
The functional polysiloxane is generally present in the curable coating composition of the present invention in amounts of 5 to about 65, and preferably from about 10 to about 25 percent by weight based on total weight of resin solids. The polyamine or blocked polyamine is generally present in amounts of from 25 to about 65, and preferably from about 35 to about 55 percent by weight based on total weight of resin solids. The optional polyacrylate functional material can be present in amounts up to 15, and preferably from about 2.5 to about 7.5 percent by weight based on total weight of resin solids.
The coating composition of the invention can be applied to the substrate by any conventional method such as brushing, dipping, flow coating, roll coating and spraying. Typically, they are most often applied by spraying. The compositions can be applied over a wide variety of primed and unprimed substrates such as wood, metal, glass, cloth, plastics, leather, foams and the like. Although the compositions can be cured at ambient temperatures, they can be cured at elevated temperatures to hasten the cure. An example would be forced air curing in a down draft booth at about 40° to 60° C. which is common in the automotive refinish industry.
The compositions of the invention in the pigmented form can be applied directly to a substrate to form a color coat. The color coat may be in the form of a primer for subsequent application of a top coat or may be a colored top coat. When used as a primer coating, thicknesses of 0.4 to 4.0 mils are typical. When used as a color top coat, coating thicknesses of about 0.5 to 4.0 mils are usual.
In applying composite coatings using the coating composition of the present invention, the initially applied coating can be cured prior to the application of the second coat. Alternatively, the coating can be applied by a wet-on-wet technique in which the second coating is applied to the first coating (usually after a flash time at room temperature or slightly elevated temperature to remove solvent or diluent, but insufficient time to cure the coating) and the two coatings are co-cured in a single step.
Only one of the coatings in the composite coating needs to be based on the coating composition of the present invention. The other coating composition can be based on a film-forming system containing a thermoplastic and/or thermosetting film-forming resin well known in the art such as cellulosics, acrylics, polyurethanes, polyesters including alkyds, aminoplasts, epoxies and mixtures thereof. These film-forming resins are typically formulated with various other coatings ingredients such as pigments, solvents and optional ingredients mentioned above.
The curable coating compositions of the present invention are particularly useful as primer surfacer coating compositions for automotive refinish applications. The compositions can be applied by any of the foregoing means of application directly to bare metal surfaces and, after being allowed to dry and the finish prepared such as by sanding, coated directly with a color top coat or a color-clear composite coating. The claimed coating compositions can be used as a single primer or undercoat beneath a top coat replacing separate undercoats which have historically been required to obtain optimum results.
The following examples illustrate the invention and should not be construed as a limitation on the scope thereof. Unless specifically indicated otherwise, all percentages and amounts are by weight.
EXAMPLE 1
This example describes the preparation of a disiloxane tetrol, a product of the hydrosilylation step in the preparation of the acetoacetate functional polysiloxane of the present invention. The disiloxane tetrol was prepared from the following mixture of ingredients:
______________________________________ Equivalent Parts By WeightIngredients Weight Equivalents (grams)______________________________________Charge I:Trimethylolpropane 174.0 7.7 1335.7monoallyletherCharge II:1,1,3,3-tetramethyldi- 67.0 7.7 515.2siloxaneCharge III:Chloroplatinic acid 10 ppm______________________________________
To a suitable reaction vessel equipped with a means for maintaining a nitrogen blanket, Charge I and an amount of sodium bicarbonate equivalent to 20 to 25 ppm of total monomer solids were added at ambient conditions and the temperature was gradually increased to 75° C. under a nitrogen blanket. At that temperature, about 5.0% of Charge II was added under agitation, followed by the addition of Charge III, equivalent to 10 ppm of active platinum based on total monomer solids. The reaction was then allowed to exotherm to 95° C. at which time the remainder of Charge II was added at a rate such that the temperature did not exceed 95° C. After completion of this addition, the reaction temperature was maintained at 95° C. and monitored by infrared spectroscopy for disappearance of the silicon hydride absorption band (Si--H, 2150 cm -1 ).
EXAMPLE 2
This example describes the preparation of a polysiloxane tetrol, a product of the hydrosilylation of MASILWAX BASE siloxane with an approximate degree of polymerization of 3 to 4, i.e., (SiO) 3 to (SiO) 4 . The siloxane tetrol was prepared from the following mixture of ingredients:
______________________________________ Equivalent Parts By WeightIngredients Weight Equivalents (grams)______________________________________Charge I:Trimethylolpropane 174.0 9.4 1630.0monoallyletherCharge II:MASILWAX BASE.sup.1 156.7 9.4 1467.4Charge III:Chloroplatinic acid 10 ppm______________________________________ .sup.1 Polysiloxane containing silicon hydride, commercially available from PPG Industries, Inc.
To a suitable reaction vessel equipped with a means for maintaining a nitrogen blanket, Charge I and an amount of sodium carbonate equivalent to 20 to 25 ppm of total monomer solids were added at ambient conditions and the temperature was gradually increased to 75° C. under a nitrogen blanket. At that temperature, about 5.0% of Charge II was added under agitation, followed by the addition of Charge III, equivalent to 10 ppm of active platinum based on total monomer solids. The reaction was then allowed to exotherm to 95° C. at which time the remainder of Charge II was added at a rate such that the temperature did not exceed 95° C. After completion of this addition, the reaction temperature was maintained at 95° C. and monitored by infrared spectroscopy for disappearance of the silicon hydride absorption band (Si-H, 2150 cm -1 ).
EXAMPLE 3
This example describes the preparation of a disiloxane propoxyldiol, a product of the hydrosilylation step of tetramethyl disiloxane. The disiloxane propoxyldiol was prepared from the following mixture of ingredients:
______________________________________ Equivalent Parts By WeightIngredients Weight Equivalents (grams)______________________________________Charge I:Allyl Propoxylate.sup.1 150.8 3.0 452.4Charge II:Tetramethyldisiloxane 67.0 3.0 201.0Charge III:Chloroplatinic acid 10 ppm______________________________________ .sup.1 Commercially available as ARCAL AP1375 from ARCO Chemical Company.
To a suitable reaction vessel equipped with a means for maintaining a nitrogen blanket, Charge I and an amount of sodium bicarbonate equivalent to 20 to 25 ppm of total monomer solids were added at ambient conditions and the temperature was gradually increased to 75° C. under a nitrogen blanket. At that temperature, about 5.0% of Charge II was added under agitation, followed by the addition of Charge III, equivalent to 10 ppm of active platinum based on total monomer solids. The reaction was then allowed to exotherm to 95° C. at which time the remainder of Charge II was added at a rate such that the temperature did not exceed 95° C. After completion of this addition, the reaction temperature was maintained at 95° C. and monitored by infrared spectroscopy for disappearance of the silicon hydride absorption band (Si--H, 2150 cm -1 ).
EXAMPLE 4
This example describes the preparation of a polysiloxane propoxyldiol, a product of the hydrosilylation of MASILWAX. The polysiloxane propoxyldiol was prepared from the following mixture of ingredients:
______________________________________ Equivalent Parts By WeightIngredients Weight Equivalents (grams)______________________________________Charge I:Allyl Propoxylate.sup.1 150.8 3.0 452.4Charge II:MASILWAX BASE.sup.2 156.7 3.0 468.0Charge III:Chloroplatinic acid 10 ppm______________________________________ .sup.1 Commercially available as ARCAL AP1375 from ARCO Chemical Company. .sup.2 Polysiloxanecontaining silicon hydride, commercially available fro PPG Industries, Inc.
To a suitable reaction vessel equipped with a means for maintaining a nitrogen blanket, Charge I and an amount of sodium bicarbonate equivalent to 20 to 25 ppm of total monomer solids were added at ambient conditions and the temperature was gradually increased to 75° C. under a nitrogen blanket. At that temperature, about 5.0% of Charge II was added under agitation, followed by the addition of Charge III, equivalent to 10 ppm of active platinum based on total monomer solids. The reaction was then allowed to exotherm to 95° C. at which time the remainder of Charge II was added at a rate such that the temperature did not exceed 95° C. After completion of this addition, the reaction temperature was maintained at 95° C. and monitored by infrared spectroscopy for disappearance of the silicon hydride absorption band (Si--H, 2150 cm -1 ).
EXAMPLE 5
This example describes the preparation of a styrenated polysiloxane polyol, a product of the hydrosilylation of a polysiloxane with an approximate degree of polymerization of 34, i.e., (Si--O) 34 . The polysiloxane polyol was prepared from the following mixture of ingredients:
______________________________________ Equivalent Parts By WeightIngredients Weight Equivalents (grams)______________________________________Charge I:Alpha-methylstyrene 118.0 2.3 272.9Polysiloxane (Si--O).sub.34.sup.1 162.2 3.1 501.5Charge II:Trimethylolpropane 174.0 .97 168.0monoallyletherCharge III:Chloroplatinic acid 10 ppm______________________________________ .sup.1 Polysiloxane (Si--O).sub.34 containing silicon hydride.
To a suitable reaction vessel equipped with a means for maintaining a nitrogen blanket, Charge I was added at ambient conditions. Added to the reaction vessel was 135 microliters, 7.5% solution of chloroplatinic acid, equivalent to 10 ppm of active platinum based on total monomer solids. The temperature was gradually increased to 80° C. under a nitrogen blanket. The reaction was then allowed to exotherm to 151° C., then subsequently cooled back to 80° C., at which time Charge II was added. with 70 ppm of potassium acetate. The reaction was again allowed to exotherm to approximately 150° C. before cooling to and maintaining at 95° C. while monitoring by infrared spectroscopy for disappearance of the silicon hydride absorption band (Si--H, 2150 cm -1 ).
EXAMPLE 6
This example describes the acetoacetylation of the disiloxane tetrol of Example 1 to produce the acetoacetate functional polysiloxane of the present invention. The acetoacetate functional polysiloxane was prepared from the following mixture of ingredients:
______________________________________ Equivalent Parts By WeightIngredients Weight Equivalents (grams)______________________________________Charge IDisiloxane tetrol of 123.4 0.8 100.0Example 1Charge IITertiary butylacetoacetate 158.0 0.8 126.4______________________________________
To a suitable reaction vessel equipped with a means for a nitrogen sparge were added Charge I and Charge II at ambient conditions. The temperature was gradually increased to 120° C. under a nitrogen sparge. During heating, the evolving tertiary butanol was collected and atmospheric distillation was continued for about one hour at 120° C. at which time the remaining t-butanol was removed by vacuum distillation (at 30 mm Hg). Completion of the distillation provided the acetoacetate functional polysiloxane of the present invention which was confirmed by the OH value, volume of tertiary butanol collected and the disappearance of OH as determined by IR analysis. Also, the structure can be determined by NMR and elemental analysis.
EXAMPLE 7
This example describes the acetoacetylation of the polysiloxane tetrol of Example 2 to produce the acetoacetate functional polysiloxane of the present invention. The acetoacetate functional polysiloxane was prepared from the following mixture of ingredients:
______________________________________ Equivalent Parts By WeightIngredients Weight Equivalents (grams)______________________________________Charge IPolysiloxane tetrol of 179.2 2.2 385.6Example 2Charge IITertiary butylacetoacetate 158.0 2.2 340.0______________________________________
To a suitable reaction vessel equipped with means for a nitrogen sparge were added Charge I and Charge II at ambient conditions. The temperature was gradually increased to 120° C. under a nitrogen sparge. During heating, the evolving tertiary butanol was collected and atmospheric distillation was continued for about one hour at 120° C. at which time the remaining t-butanol was removed by vacuum distillation (at 30 mm Hg). Completion of the distillation provided the acetoacetate functional polysiloxane of the present invention which was confirmed by the methods in Example 6.
EXAMPLE 8
This example describes the acetoacetylation of the polysiloxane propoxyldiol of Example 4 to produce the acetoacetate functional polysiloxane of the present invention. The acetoacetate functional polysiloxane was prepared from the following mixture of ingredients:
______________________________________ Equivalent Parts By WeightIngredients Weight Equivalents (grams)______________________________________Charge IPolysiloxane propoxyldiol 283.3 2.8 800.0of Example 4Charge IITertiary butylacetoacetate 158.0 2.8 445.6______________________________________
To a suitable reaction vessel equipped with means for a nitrogen sparge were added Charge I and Charge II at ambient conditions. The temperature was gradually increased to 120° C. under a nitrogen sparge. During heating, the evolving tertiary butanol was collected and atmospheric distillation was continued for about one hour at 120° C. at which time the remaining t-butanol was removed by vacuum distillation (at 30 mm Hg). Completion of the distillation provided the acetoacetate functional polysiloxane of the present invention which was confirmed by the methods in Example 6.
EXAMPLE 9
This example describes the acetoacetylation of the styrenated polysiloxane polyol of Example 5 to produce the acetoacetate functional polysiloxane of the present invention. The acetoacetate functional polysiloxane was prepared from the following mixture of ingredients:
______________________________________ Equivalent Parts By WeightIngredients Weight Equivalents (grams)______________________________________Charge IStyrenated polysiloxane of 485.3 0.649 315.0Example 5Charge IITertiary butylacetoacetate 158.0 0.649 102.5______________________________________
To a suitable reaction vessel equipped with means for a nitrogen sparge were added Charge I and Charge II at ambient conditions. The temperature was gradually increased to 120° C. under a nitrogen sparge. During heating, the evolving tertiary butanol was collected and atmospheric distillation was continued for about one hour at 120° C. at which time the remaining t-butanol was removed by vacuum distillation (at 30 mm Hg). Completion of the distillation provided the acetoacetate functional polysiloxane of the present invention which was confirmed by the methods in Example 6.
EXAMPLE 10
This example describes the preparation of a two-component curable primer coating composition containing the acetoacetylated disiloxane tetrol of Example 6. The pre-blended crosslinker component, which contains the acetoacetylated disiloxane tetrol, was combined under agitation with the pigmented component which is commercially available as NCP-270 from PPG Industries, Inc. just prior to application to a metal substrate.
______________________________________ Formula Weight Solid WeightINGREDIENT (grams) (grams)______________________________________PIGMENTED COMPONENT:methyl isobutyl ketone (MIBK) 26.3 --butyl acetate 28.8 --xylene 16.7 --novalac ketimine resin (in MIBK).sup.1 42.7 35.2acrylic grind resin (in Butyl Acetate).sup.8 6.7 4.0Dysperbyk 110.sup.2 4.4 2.2MPA2000T polyethylene wax.sup.3 2.1 0.4talc 77.9 77.9Bentone SD-2.sup.4 3.9 3.9Titanium dioxide 31.5 31.5barium sulfate 35.1 35.1silica .9 .9zinc phosphate 32.3 32.3iron oxide 6.5 6.5carbon black 1.1 1.1butyl acetate 8.6 --ketimine resin (in MIBK).sup.7 26.3 24.5Subtotal 351.8 255.5CROSSLINKER COMPONENT:acetone 6.7 --methyl amyl ketone 7.6 --xylene 7.1 --siloxane acetoacetate of Example 6 51.9 51.9epoxy silane.sup.5 5.0 5.0diacrylate resin.sup.6 5.0 5.0isostearic acid .2 .2Subtotal 83.5 62.1Total 435.3 317.6______________________________________ .sup.1 Reaction product of an epoxy novalac (EPN 1139) available from Cib Geigy and the ketimine of diethylene triamine and methyl isobutyl ketone. .sup.2 Wetting agent available from BYKChemie. .sup.3 Wax dispersion available from Rheox Inc. .sup.4 Antisettling agent available from Rheox Inc. .sup.5 Adhesion promoter available as A187 from OSi Specialties Inc. .sup.6 Bisphenol A diacrylate available from Sartomer Corp. .sup.7 Ketimine of isophorone diamine and MIBK. .sup.8 Acrylic copolymer of styrene, diethyl aminoethyl methacrylate, methyl methacrylate, hydroxyethyl methacrylate, 2ethylhexyl acrylate and 2ethylhexyl methacrylate (23.1/21.5/18.5/18.0/9.2/9.2 weight ratio); 60% solids in butyl acetate.
EXAMPLE 11
This example describes the preparation of a two-component curable primer coating composition containing the acetoacetylated polysiloxane tetrol of Example 7 in accordance with the present invention. The pre-blended crosslinker component which contains the acetoacetylated polysiloxane tetrol was combined under agitation with the pigmented component, which is commercially available as NCP-270 from PPG Industries, Inc., just prior to application to a metal substrate.
______________________________________ Formula Weight Solid WeightINGREDIENT (grams) (grams)______________________________________PIGMENTED COMPONENT:Methyl isobutyl ketone (MIBK) 10.9 --Butyl acetate 11.9 --Xylene 6.9 --Novalac ketimine resin (in MIBK) as in 17.6 14.5Example 10Acrylic grind resin (in butyl acetate) as in 2.8 1.7Example 10Dysperbyk 110 1.8 .9MPA2000T polyethylene wax .9 .2Talc 32.1 32.1Bentone SD-2 1.6 1.6Titanium dioxide 13.0 13.0Barium sulfate 14.5 14.5Silica .4 .4Zinc phosphate 25.7 25.7Iron oxide 2.7 2.7Carbon black .5 .5Butyl acetate 3.5 --Ketimine resin (in MIBK) as in Example 10 10.9 10.2Subtotal 157.7 118.0CROSSLINKER COMPONENT:Acetone 6.8Methyl amyl ketone 3.8Xylene 3.5Polyester acetoacetate resin.sup.1 16.4 16.4Siloxane acetoacetate of Example 7 6.8 6.8Epoxy silane as in Example 10 2.5 2.5Diacrylate resin as in Example 10 2.5 2.5Isostearic acid .1 .1SUBTOTAL 42.4 28.3Total 200.1 146.3______________________________________ .sup.1 Acetoacetylated polyester made from neopentyl glycol/trimethylol propane/ethylene glycol/cyclohexyl dimethanol/isophthalic anhydride, 1,4cyclohexyl dicarboxylic acid/tertiary butyl acetoacetate (2.4/16.7/2.9/3.3/7.7/8.0/59.0 weight ratio).
COMPARATIVE EXAMPLE 12
By way of comparison, this example describes the preparation of a two component curable primer coating composition which contains in the crosslinker component an acetoacetate functional polyester only, with no acetoacetate functional siloxane. The pre-blended crosslinker component, which contains the acetoacetylated polyester, and is commercially available as NCX 275 from PPG Industries, Inc. is combined under agitation with the pigmented component which is commercially available as NCP-270 from PPG Industries, Inc. just prior to application to a metal substrate.
______________________________________ Formula Solid WeightINGREDIENT Weight (grams) (grams)______________________________________PIGMENTED COMPONENT:Methyl isobutyl ketone (MIBK) 21.5 --Butyl acetate 23.5 --Xylene 13.7 --Novalac ketimine resin (in MIBK) as in 35.0 28.9Example 10Acrylic grind resin (in BuAcetate) as in 5.5 3.3Example 10Dysperbyk 110 3.6 1.8MPA2000T polyethylene wax 1.7 .34Talc 63.7 63.7Bentone SD-2 3.2 3.2Titanium dioxide 25.8 25.8Barium sulfate 28.7 28.7Silica .8 .8Zinc phosphate 50.9 50.9Iron oxide 5.3 5.3Carbon black .9 .9Butyl acetate 7.0 --Ketimine resin (in MIBK) as in 21.7 20.1Example 10Subtotal 311.6 233.7CROSSLINKER COMPONENT:Acetone 11.1 --Methyl amyl ketone 6.3 --Xylene 5.8 --Polyester acetoacetate resin as in 38.0 38.0Example 10Epoxy silane as in Example 10 4.1 4.1Diacrylate resin as in Example 10 4.1 4.1Isostearic acid .1 .1Subtotal 69.5 46.3Total 381.0 280.0______________________________________
Prior to coating, test panels of various metal substrates were prepared by mechanically abrading the surface with a machine sander and cleaning the panel of sanding residue. Each of the primer coating compositions from the above Example 10 and Comparative Example 12 were spray applied using conventional spray equipment to a variety of metal substrate test panels and allowed to cure at ambient conditions for two hours. A basecoat/clearcoat system, DBC-9700/DCU-2020, commercially available from PPG Industries, Inc. was spray applied using conventional spray equipment and allowed to cure at ambient conditions for one week. The multilayer coating system was tested for adhesion under various conditions.
Each of the primer coating compositions from the above Example 11 and Comparative Example 12 were spray applied using conventional spray equipment to test panels of cold rolled steel and electrogalvanized steel substrate which had been mechanically abraded and cleaned of all sanding residue. The primer coatings were allowed to cure at ambient conditions for two hours. A commercial topcoat, DCC-9300, available from PPG Industries, Inc. was spray applied using conventional spray equipment and allowed to cure at ambient conditions for one week. The multilayer coating system was tested for adhesion under various conditions.
These formulations were examined for adhesion to a variety of substrates via ASTM D-3359. The results are reported on a scale of 0-5 with a 5 representing 100% adhesion and a 0 representing greater than 65% loss of adhesion. A rating of 4 represents less than 5% adhesion loss, 3 represents an adhesion loss of 5-15%, a 2 represents an adhesion loss of 15-35% and 1 represents an adhesion loss of 35-65%. Adhesion was also determined after humidity resistance testing. Humidity resistance is performed by placing the cured panels in a cabinet maintained at 100° F. and 100% relative humidity for a total of 96 hours. The panels are then removed and examined for adhesion immediately and again after 4 hours recovery at room temperature and humidity. Test results for Example 10 and Comparative Example 12 are summarized in the following TABLE 1. The results for Example 11 and Comparative Example 12 are summarized in the following TABLE 2.
TABLE 1__________________________________________________________________________COATING ADH. ADH. ADH. ADH. HUMIDITYFORMULATION SUBSTRATE 24 hrs 7 days Hum. Rec. COMMENTS__________________________________________________________________________Example 10 aluminum 5 5 4 5 goodExample 12 aluminum 5 5 1 3 good(Comparative)Example 10 cold rolled steel 5 5 5 5 goodExample 12 cold rolled steel 5 5 1 5 good(Comparative)Example 10 electrogalvanized steel 5 5 4 5 goodExample 12 electrogalvanized steel 0 0 0 0 microblisters(Comparative)Example 10 galvanneal steel 5 5 0 5 dense microblistersExample 12 galvanneal steel 0 0 0 0 small blisters(Comparative)__________________________________________________________________________
TABLE 2__________________________________________________________________________COATING ADH. ADH. ADH. ADH. HUMIDITYFORMULATION SUBSTRATE 24 hrs. 7 days Hum. Rec. COMMENTS__________________________________________________________________________Example 11 cold rolled steel 5 5 4 4 goodExample 11 electrogalvanized steel 5 5 3 4 goodExample 12 cold rolled steel 5 5 2 3 slight(comparative) blisteringExample 12 electrogalvanized steel 5 5 0 2 moderate(comparative) blistering__________________________________________________________________________
EXAMPLE 13
This example describes the preparation of a two-component curable sealer coating composition containing the acetoacetylated polysiloxane tetrol of Example 7 in accordance with the present invention. The pre-blended crosslinker component which contains the acetoacetylated polysiloxane tetrol was combined under agitation with the pigmented component just prior to application to a metal substrate.
______________________________________ Formula Weight Solid WeightINGREDIENT (grams) (grams)______________________________________PIGMENTED COMPONENT:Methyl amyl ketone (MAK) 2.7 --Butyl acetate 2.6 --Xylene 2.9 --Novalac ketimine resin of Example 10 20.4 16.6Methyl isobutyl ketone 2.7MPA 200T polyethylene waxBENTONE SD-2 0.8 0.8Silicone additive.sup.1 1.3 0.7Talc 17.9 17.9Neutral TiO.sub.2 27.6 27.6Barium sulfate 18.8 18.8Silica 0.4 0.4Carbon black 0.2 0.2Silicone additive.sup.2 0.2 0.1Methyl isobutyl ketone 5.3 --Ketimine resin in MAK.sup.3 7.1 5.5Methyl amyl ketone 5.7 --Butyl benzyl phthalate 4.3 4.3Silicone additive.sup.1 0.7 --Subtotal 122.9 93.1Acetone 11.9 --Methyl amyl ketone 15.3 --Xylene 2.8 --Siloxane acetoacetate of Example 7 39.4 39.4Adhesion promoter as in Example 10 3.7 3.7Diacrylate resin as in Example 10 3.7 3.7Isostearic acid 0.1 0.1Subtotal 76.9 46.9Total 199.8 140.0______________________________________ .sup.1 Wetting agent commercially available as DISPERBYK 163 from BYKChemie USA. .sup.2 Polymethylsiloxane solution commercially available as DC200 from Dow Corning Corp. .sup.3 Methylamyl ketone ketimine of diethylene triamine, 78% resin solid in methylamyl ketone.
COMPARATIVE EXAMPLE 14
By way of comparison, this example describes the preparation of a two component curable sealer coating composition which contains in the crosslinker component an acetoacetate functional polyester only, with no acetoacetate functional siloxane. The pre-blended crosslinker component, which contains the acetoacetate functional polyester, was combined under agitation with the pigmented component just prior to application to a metal substrate.
______________________________________ Formula Weight Solid WeightINGREDIENT (grams) (grams)______________________________________PIGMENTED COMPONENT:Methyl amyl ketone 2.7 --Butyl acetate 2.6 --Xylene 2.9 --Novalac ketimine resin as in 20.4 16.6Example 10Methyl isobutyl ketone 2.7Polyethylene wax as in Example 13Anti-settling agent 0.8 0.8Silicone additive as in Example 13 1.3 0.7Talc 17.9 17.9Neutral TiO.sub.2 27.6 27.6Barium sulfate 18.8 18.8Silica 0.4 0.4Carbon black 0.2 0.2Silicone additive DC 200 0.2 0.1Methyl isobutyl ketone 5.3 --Ketimine resin in MAK as in 7.1 5.5Example 13Methyl amyl ketone 5.7 --Butyl benzyl phthalate 4.3 4.3Silicone additive DISPERBYK 0.7 --Subtotal 122.9 93.1Acetone 11.9 --Methyl amyl ketone 15.3 --Xylene 2.8 --Polyester acetoacetate as in Example 11 39.4 39.4Adhesion promoter as in Example 13 3.7 3.7Diacrylate resin as in Example 13 3.7 3.7Isostearic acid 0.1 0.1Subtotal 76.9 46.9Total 199.8 140.0______________________________________
Test panels were prepared by hand sanding APR24711 test panels supplied by ACT Laboratories, Inc. with 360 grit paper to remove contaminants and cleaning to remove sanding residue. The sealer coating formulations of Example 13 and Comparative Example 14 were spray applied to prepared test panels using conventional spray equipment and allowed to cure at ambient conditions for 4 hours. A commercial basecoat/clearcoat system, DBU-3822/DCU-2001 available from PPG Industries, Inc., was applied to the cured sealers and allowed to cure at ambient conditions for one week. The multilayer coating systems were then tested for chip resistance by impacting the coated panels with 3 mm steel shot and varying velocities at -22° C. Results are reported as the average area of coating which exhibits failure caused by impacts at each of three impact speeds. Chip resistance test results are reported for sealer coatings of Example 13 and Comparative Example 14 in the following TABLE 3.
TABLE 3______________________________________ AVG. AREA DAMAGEDSPEED OF AVG. AREA DAMAGED EXAMPLE 14IMPACT EXAMPLE 13 (COMPARATIVE)______________________________________55 mph 13.7 mm.sup.2 46.3 mm.sup.275 mph 25.4 mm.sup.2 63.6 mm.sup.295 mph 33.3 mm.sup.2 79.0 mm.sup.2______________________________________ | Functional polysiloxanes containing acetoacetate and curable coating compositions containing such polysiloxanes are disclosed. The curable compositions are usefull in coatings where they provide excellent appearance, pot-life, humidity resistance and improved adhesion to galvanized steel substrates. A method for preparing the functional polysiloxanes is also disclosed. | 2 |
FIELD OF THE INVENTION
This invention relates to complexes of ultraviolet absorbers with quaternary ammonium compounds which are substantially free from unwanted salts. Such complexes are formed through ionic bonds formed between the two compounds. The inventive complexes are then removed of substantially all excess inorganic salt so as to obtain an UV absorber compound which exhibits improved light- and washfastness properties, which easily coats subject surfaces, which provides excellent non-fogging and non-cracking characteristics, and which also possesses anti-static, anti-microbial, and anti-abrasion properties. This invention also concerns methods of making and utilizing such inventive ultraviolet absorbing complexes.
BACKGROUND OF THE PRIOR ART
All of the patents cited throughout this specification are hereby entirely incorporated herein.
Quaternary ammonium compounds are well known as complexing agents for certain compounds, such as anionic dyes. For example, U.S. Pat. No. 5,059,244, to King, discloses an aqueous solution of anionic dyes and an ethoxylated triethanolamine. This composition is useful as an ingredient within ink formulations and as an agent for temporarily tinting textile fibers. Quaternary ammonium compounds have been disclosed as useful auxiliary agents for printing on fiber materials. For example, U.S. Pat. No. 3,785, 767, to Hildebrand, discloses a pad-steaming process for the continuous dyeing and printing of fiber material with a formulation containing anionic dyes and amine salts. Other pertinent teachings of include U.S. Pat. No. 4,563,190, to Topfl, which discloses a dyeing assistant formulation for anionic dyes containing quaternary ammonium compounds that contain at least one basic nitrogen atom to which are attached at least one polyglycol ether chain; U.S. Pat. No. 4,935,033, to Mosimann et al., which discloses a dyeing method for natural polyamide fibers using reactive dyes and a dyeing assistant agent containing a quaternary ammonium compound; and U.S. Pat. No. 4,369,041, to Dvorsky et al., discloses a technique for printing textiles involving exposing the textile to the action of quaternary ammonium compounds before or during the dyeing or printing with acid dyes. Furthermore, Aston et al., U.S. Pat. No. 5,403,358, discloses a pretreatment composition for ink jet which comprises a quaternary ammonium compound and a reactive dye. Such anionic dyes and quaternary ammonium compounds also find application in other areas, for instance: U.S. Pat. No. 4,459130, to Helling et al., discloses a dye preparation which is consisted of an acid dye and a basic carrier which contains quaternary ammonium or phosphonium groups; and U.S. Pat. No. 5,266,077, to Auten et al., discloses a method for tinting a hydrophilic contact lens through the action of a quaternary ammonium compound as a dye complexing agent.
However, there is no teaching specifically complexing a known ultraviolet absorber with a quaternary ammonium compound to form a more versatile UV absorber, not to mention there is no teaching of such a complex which is substantially free from unwanted salts. The closest prior art, U.S. Pat. No. 5,376,304, to Yamamoto et al., discloses a ceric oxide sol (no UV absorber, but it ultimately performs a UV absorption function) which is basically a complex of an anionic compound which is substantially salt-free and a ceric oxide which is, possibly, further reacted with what may be a quat compound. If such a reaction does take place, patentee does not teach nor fairly suggest the performance of a subsequent post-quat reaction salt removal procedure. Furthermore, patentee's initial salt-free anionic compound is not an ultraviolet absorbing compound; however, the resultant ceric oxide sol does exhibit ultraviolet absorption properties.
It has been found that the complexation of an ultraviolet absorber with a quaternary anmmonium compound and the subsequent removal of substantially all the excess salt (formed from the reaction between the cation of the anionic UV absorber and the counter-ion of the quat) produces a compound which possesses the highly desired and unexpected characteristics such as, merely as non-limiting examples, lower incidences of cracking and improved fogging properties. Traditional UV absorbers, such as benzotriazole and benzophenone derivatives, are present on coated substrates as small organic molecules. When dispersed within coating compositions, such traditional absorbers tend to separate from the coating over time and crystallize within the coating on the target substrate. This potential for recrystallization by the traditional UV absorbing compounds thus would cause disassociation of the coating itself through cracking. Furthermore, standard UV absorbers readily sublimate from substrate coatings and produce "fog" which accumulates on other nearby surfaces. Undesirable lightly opaque films form on such surfaces (i.e., the inside of car windows) after a certain length of time of application of the absorber. Such cracking and fogging both diminish the aesthetics of the subject substrate (such as apparel, or upholstery, or the like) and could produce unwanted films on surrounding surfaces. It has been found that the complexation between an ultraviolet absorber and a quat compound provides a compound, upon further removal of substantially all unwanted salt, will not produce such problematic incidences as cracking or fogging on the coated subject substrate. Also, the inventive complex is easily dispersed and dissolved within any standard UV absorber coating composition. Additionally, the presence of such a quat component unexpectedly provides other benefits including anti-static and anti-microbial properties. Therefore, through the utilization of inexpensive reactions and quaternary ammonium compounds, the cost of providing a non-fogging, anti-static, anti-microbial, uniform film-forming, ultraviolet absorbing compound for myriad substrates can be greatly reduced. Therefore, it has been found that substantially salt-free UV absorber/quaternary ammonium complexes provide a cost-effective method of providing a great deal of highly desirable and beneficial properties to many different substrates.
When placed in a complexing solution, the ultraviolet absorber and the quaternary ammonium show a great affinity for one another such that upon disassociation with their respective cations and/or counter ions, the complexation of the absorber and quat drives the formation of unwanted excess salts comprised of the free cations and counter ions. Once the salts are formed, they are easy to remove through standard filtration, phase separation, or extraction techniques. These salts are generally inorganic in nature, although organic cations and counter-ions may also be present and thus should be substantially removed from the inventive complex. Such a salt removal ensures the absorber and quat will remain in a complex together rather than potentially reacting with free cation and/or counter ion upon disassociation within the resultant UV absorber solution. Thus, the desired properties are obtained with a greater amount of the absorber/quat complex and a much lower amount of residual unwanted salt. The term "substantially salt-free" is thus intended to mean free from such unwanted cation/counter-ion salts.
OBJECTS OF THE INVENTION
It is therefore an object of this invention to provide a substantially salt-free complex of ultraviolet absorbers and quaternary ammonium compounds, as improved UV absorbing compounds for various substrates and media. A further objective of this invention is to provide an ultraviolet absorbing compound which can be used for the treatment of textile, paper, wood, and any other surfaces which are exposed to photo-degradations.
SUMMARY OF THE INVENTION
Substantially salt-free ultraviolet absorber/quat complexes, and, more importantly, the advantages and applications of such substantially salt-free complexes have heretofore been unexplored. Anionic UV absorbers, which are the preferred types within the inventive complex might contain a certain amount of inorganic or organic salts. As discussed in greater detail below, such salts are also byproducts from the complexation between anionic UV absorbers and quaternary ammonium compounds. With the presence of such salts in the composition, either the quaternary ammonium compounds or the inorganic cations may serve as counter ions for the complexed anionic absorbers. As a result, the chances for continued complexation between the absorber and quat components decreases with the presence of increased amounts of inorganic salts. Since the UV absorber and quat compounds will disassociate in solution, some free anionic UV absorber will inevitably bond to free cations and some free quat will inevitably bond with free counter ions, thereby lowering the overall lightfastness, non-fogging, and non-migratory effect of the absorber/quat complex. This deleterious effect is thus more pronounced upon greater amounts of residual inorganic salt. Thus, salt-containing heterogeneous UV absorber/quat complex systems show uneven solubility, poor coating, and the like, in different substrate treatments. Such complexes are therefore unsuitable as UV absorbing compounds.
It has been discovered that a substantially salt-free anionic ultraviolet absorber/quaternary ammonium complex colorant, provides favorable migration, anti-fogging, anti-static, anti-microbial, uniform film-forming, and lightfastness characteristics as a treatment agent for textiles, paper, wood, plastics, and the like. Uniform films of UV absorbers are highly desired because such films resist cracking, do not build up or accumulate in discrete areas of subject substrates, and are not prone to degradation, and thus do not create "fog." The removal of inorganic salts provides an improved stability for the complexes. Furthermore, the aforementioned physical properties of the complex can be tailored to any particular requirement by altering the structure of the quaternary ammonium compound. For instance, a more hydrophobic quaternary ammonium structure affords the user, upon complexation with an anionic UV absorber and removal of substantially all of the resultant salt, an ultraviolet absorber which is more soluble within hydrophobic coating systems.
The inventive complexes can be used for providing extensive benefits, as those mentioned previously, to various different and diverse media and substrates. Virtually all types and classes of ultraviolet absorbers can be adopted to practice this invention; however, preferred as those which are anionic in nature. More preferred are those anionic absorbers which are based on benzotriazole, benzimidazole, triazine, or benzophenone systems, such as, as merely preferred examples, sulfonated hydroxybenzotriazole (trade name Cibafast® W), sodium 2-hydroxy-4-methoxy-5-sulfo-benzophenone, 2-phenylbenzimidazole-5-sulfonic acid, and sodium 2,2'-dihydroxy-4,4'-dimethoxy-5,5'-disulfobenzophenone; most preferred is Cibafast® W, available from Ciba Geigy. Such UV absorbers are well known to possess desired absorption characteristics; however, they do not provide appreciable levels of anti-cracking, anti-fogging, anti-static, anti-abrasion, and/or anti-microbial benefits. Furthermore, as utilized in their pure, unaltered states, these compounds do not possess the requisite degree of lightfastness which is necessary for long-lasting single application (and thus cost-effective) ultraviolet protection. The cationic ammonium group bonds with free reactive groups (i.e., sulfonic and/or carboxylic acid) on the anionic UV absorber so as to form ionic bonds. It is not fully understood how the interaction between the cationic moiety of the quaternary ammonium and the anionic moieties of the absorber is accomplished; however, as discussed above, it is evident that the quaternary ammonium compound has a greater affinity for the anionic UV absorber rather than for the anionic counter ion to which such quats are generally bonded. The same holds true for the anionic UV absorber which has more of an affinity for the cationic quat rather than for the cationic counter ion. Upon complexation, then, as discussed extensively above, the free counter ions of both components react together to form the aforementioned unwanted salts which require removal (at least to a substantial extent) from the resultant complex in order to provide the desired beneficial properties. The permissible level of remaining salt, and thus the definition of substantially salt-free for this invention, within the inventive complex is, at most, about 5,000 ppm. In theory, it is impossible to remove all of the unwanted salt from such complexes; however, at such low, permissible, and attainable levels of salt content, the desired lightfastness, anti-fogging, anti-cracking, migration, anti-static, anti-microbial, and the like, characteristics may be obtained. Certainly, a level of no salt at all would be most preferred, although such a level is, as noted above, nearly impossible to achieve.
A wide range of quaternary ammonium compounds have been shown to be useful for practicing the invention. A broad list of potentially useful quats within this invention include trialkyl, dialkyl, dialkoxy alkyl, monoalkoxy, benzyl, and imidazolinium quaternary ammonium compounds. The particularly preferred quats are noted below as this is merely a broad list of different classes of quaternary ammonium compounds which may be useful within the inventive complex and method. By ways of example, and not limitation, a list of preferred classes and examples of quaternary ammonium compounds is set forth in the TABLE below:
TABLE 1______________________________________Class Example (description)______________________________________Trialkyl quats Methyl tri(hydrogenated tallow) ammonium chloride Dialkyl quats Dicoco dimethyl ammonium chloride Dialkoxy alkyl quats Methyl bis(polyethoxyethanol) coco ammonium chloride Monoalkoxy quats Methyl (polypropylene glycol) diethyl ammomium chloride Benzyl quats Dimethyl tallow benzyl ammonium chloride imidazolinium quats Methyl tallow amido-2-tallow imidazolinium methylsulfate______________________________________
Again, the examples listed above are merely preferred compounds as any such compound meeting the broadly listed classes of quats are within the scope of this invention. Further suitable quats worth mentioning, however, include tetraalkyl quats, mono-substituted polyalkoxyalkyl quats, di-substituted polyalkoxyalkyl quats, and tri-substituted polyalkoxyalkyl quats, again merely as examples. The amount of residual inorganic salts is generally between about 50 ppb and 5000 ppm. Typically sodium counter ions, and thus sodium salts, are the residual inorganic ions and salts within such anionic dyes. Monitoring of the inorganic salt level is available through conveniently and easily performed measurements of the sodium ion level within the composition. Additionally, the existence of such substantially salt-free UV absorber complexes provides an ease in handling, particularly with a liquid composition, during applications to substrates and media which is not as evident with standard UV absorbers.
Various purification techniques may be performed in order to remove substantially all of the residual unwanted salts from the complexes. Such techniques include, but are not limited to, solvent extraction, phase separation, ultrafiltration, and other filtration methods. Particularly preferred are ultrafiltration under high pressure, phase separation through the utilization of an ammonium carbonate rinsing procedure (i.e., three consecutive washings with 25% aqueous ammonium carbonate in a 1:1 weight ratio to complex), and solvent extraction filtration through the utilization of methylene chloride, chloroform, or the like. After the removal of excess inorganic salt, the resultant solution should also be stripped of excess water in order to purify the ultraviolet absorber complex.
Basically, then, the simplest manner of practicing the invention is first determine the desired UV absorber for its absorption performance, lightfastness, thermal stability, and the like, characteristics for the subject substrate to be coated; second, select the appropriate quaternary ammonium compound for the subject substrate based on the necessarily required physical properties such as migration, uniform dispersion, solubility, washfastness, and the like; third, react the two together to form a complex; and last, remove the unwanted salts from the complex.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Without limiting the scope of the invention, the preferred features of the invention are exemplified below.
Synthesis of UV Absorbing Complex
EXAMPLE 1
Three parts of sulfonated hydroxybenzotriazole (trade name Cibafast W) and four parts of bis(hydrogenated tallow alkyl)-dimethyl quaternary ammonium chloride, available from Akzo Nobel Chemicals under the trade name Arquad® 2HT-75, were dissolved into 10 parts of water/methanol solution (5/1, v/v). The solution was stirred for 2-3 hours. The polymeric UV absorbers was purified through phase separation and chloroform extraction. The purified particulate polymeric UV absorber was then dispersed into water.
EXAMPLE 2
Thirty-three parts of sodium 2-hydroxy-4-methoxy-5-sulfobenzophenone and 92 parts of methylpolyoxyethylene(15) coco ammonium chloride (available from Witco under the trade name Variquat® K1215) were dissolved in 200 parts of water. The solution was stirred for 2 hours and subsequently extracted with methylene chloride. The methylene chloride solution was then stripped under vacuum to afford a homogenous liquid.
EXAMPLE 3
Forty-eight parts of sodium 2,2'-dihydroxy-4,4'-dimethoxy-5,5'-disulfobenzophenone and 95 parts of Variquat® K1215 were dissolved in 200 parts of water. The solution was stirred for 2 hours and subsequently extracted with methylene chloride. The methylene chloride solution was stripped under vacuum to afford a homogenous liquid.
Applications for the Inventive Complex
EXAMPLE 4
Lightfastness
The water dispersion from EXAMPLE 1 was used in a textile treatment composition and procedure through a conventional padding process on 100% polyester automotive fabric. This polymeric UV absorber provided excellent UV protection for the textile substrates, was nonvolatile (and thus should not create any appreciable fogging), and also significantly improved the lightfastness of dyed fabrics. The table below presents a number of examples of the improvement of lightfastness by padding certain amounts of the UV absorber complex of EXAMPLE 1 into automotive fabrics. The automotive fabrics lightfastness testing was performed under the standard test procedures promulgated by General Motors and Chrysler, "Surface Vehicle Recommended Practice. (R) Accelerated Exposure of Automotive Interior Trim Components Using a Controlled Irradiance Water Cooled Xenon-Arc Apparatus," promulgated by The Engineering Society for Advancing Mobility Land Sea Air and Space International. The measurements within TABLE 2 indicate different color coordinates. The higher E* and H*, the better the result. The lower L* and C*, the better the result. The Examples listed within TABLE 2 below correspond to the following:
A--Control with no complex
B--0.5% complex owf (the total pad-on amount of UV absorber on the fabric)
C--1.5% complex owf
D--5.5% complex owf
E--6.5% complex owf
F--8.0% complex owf
G--10.0% complex owf
The automotive fabrics lightfastness testing was performed under the standard test procedures promulgated by General Motors and Chrysler.
TABLE 2______________________________________Example E* L* C* H*______________________________________A 4.54 4.01 -0.91 1.92 B 3.69 3.32 -0.87 1.35 C 3.29 2.90 -0.92 1.26 D 2.61 2.08 -0.73 1.42 E 3.01 2.56 -0.83 1.34 F 2.96 2.56 -0.76 1.27 G 2.95 2.83 -0.37 0.73______________________________________
Certainly, the presence of any of the inventive UV absorber complex provides a significant improvement in lightfastness over non-treated fabric and the greater the amount of inventive complex, the better the result.
EXAMPLE 5
Anti-static Properties
The UV absorber of EXAMPLE 1 also provides anti-static, anti-microbial, and anti-abrasion properties. The two following tables show results from anti-static and anti-microbial studies. TABLE 3 shows the results of testing the Electrical Resistivity of Fabric under AATCC Test Method 76. The Examples listed within TABLE 3 below correspond to the following:
H--Control (warp)
I--Control (fill)
J--3.0% complex owf (warp)
K--3.0% comples owf (fill)
L--4.0% complex owf (warp)
M--4.0% complex owf (fill)
N--5.0% complex owf (warp)
O--5.0% complex owf (fill)
TABLE 3______________________________________Anti-static Testing Example Conductivity (Amperes) Resistivity (Ω/cm.sup.2)______________________________________H 5.240 × 10.sup.-12 3.82 × 10.sup.13 I 5.560 × 10.sup.-12 3.60 × 10.sup.13 J 1.620 × 10.sup.-10 1.23 × 10.sup.12 K 1.370 × 10.sup.-10 1.46 × 10.sup.12 L 2.100 × 10.sup.-10 9.52 × 10.sup.11 M 2.850 × 10.sup.-10 7.02 × 10.sup.11 N 3.280 × 10.sup.-10 6.10 × 10.sup.11 O 3.360 × 10.sup.-10 5.95 × 10.sup.11______________________________________
Thus, the treated samples exhibited improved and beneficial anti- static properties as compared to the untreated fabric.
EXAMPLE 6
Anti-microbial Results
The anti-microbial characteristics of the inventive complex were tested using AATCC Test Method 147-1996 for growth-free zones and contact inhibition of Staphyloccocus aureus. The zone of inhibition indicates the migratory anti-microbial properties around the treated substrate. The contact inhibition test indicates the effectiveness of the anti-microbial agent on direct contact. The Examples listed within TABLE 2 below correspond to the following:
P--Control (face)
Q--Control (back)
R--1.2% complex owf (face)
S--1.2% complex owf (back)
T--0.9% complex owf (face)
U--0.9% complex owf (back)
TABLE 4______________________________________Anti-microbial Testing Example Growth-Free Zone (mm) Contact Inhibition (%)______________________________________P 0.00 0.00 Q 0.00 0.00 R 0.00 100.00 S 0.00 100.00 T 4.00 100.00 U 1.00 100.00______________________________________
Therefore, the inventive complex provides a certain degree of anti-microbial properties to treating fabrics as compared to untreated substrates.
EXAMPLE 7
Ultraviolet Absorption Characteristics
Of primary importance, however, the inventive UV absorber has proven effective in improving the sun protective factor (SPF) of fabrics. Ultraviolet (UV) radiation which has proven harmful to human skin includes the two different types known as UV-A, which falls within the range of 320-400 nm along the light spectrum, and UV-B, which is between 290-320 nm in wavelength. Any manner of reducing or preventing transmission of UV light thus must effectively block or absorb such radiation between these wavelengths (290 and 400 nm). An SPF number is measured by the following equation: 100/% transmission of UV light=SPF number. Thus, a composition permitting 20% transmission of UV light has a SPF# of 5; while a composition permitting 10% transmission has a SPF# of number of 10; and so on. The complex of EXAMPLE 1 was incorporated within a sample of Downy Care® fabric softener (5% of the total weight of the sample). The two fabrics used here are polycottons (peach-colored 65/35 polyester/cotton, V below, and purple-colored 65/35 polyester/cotton, W below). The results are tabulated as follows:
TABLE 5______________________________________Sun Protective Factor Measurements of Fabrics Treated With the Inventive Complex UV-A UV-B % UV-A % UV-B Example SPF UV-A Trans. Trans. block block______________________________________V untreated 6.5 15.30 2.90 84.70 97.10 V treated 9.9 10.10 2.70 89.90 97.30 W untreated 45.5 2.20 0.50 97.80 99.50 W treated 77.0 1.30 0.50 98.70 99.50______________________________________
Therefore, the ultraviolet absorption of the treated fabrics increased upon contact with the inventive complex. It is noted that the above results were obtained by rinsing fabrics with the complex-containing Downy® fabric softener only once. It is expected that the corresponding SPF numbers for each treated example will continually increase upon multiple rinsing.
While specific features of the invention have been described, it will be understood, of course, that the invention is not limited to any particular configuration or practice since modification may well be made and other embodiments of the principals of the invention will no doubt occur to those skilled in the art to which the invention pertains. Therefore, it is contemplated by the appended claims to cover any such modifications as incorporate the features of the invention within the true meaning, spirit, and scope of such claims. | This invention relates to complexes of ultraviolet absorbers with quaternary ammonium compounds which are substantially free from unwanted salts. Such complexes are formed through ionic bonds formed between the two compounds. The inventive complexes are then removed of substantially all excess inorganic salt so as to obtain an UV absorber compound which exhibits improved light- and washfastness properties, which easily coats subject surfaces, which provides excellent non-fogging and non-cracking characteristics, and which also possesses anti-static, anti-microbial, and anti-abrasion properties. This invention also concerns methods of making and utilizing such inventive ultraviolet absorbing complexes. | 2 |
[0001] This continuation-in-part application claims of Utility patent application Ser. No. 10/237,634, filed on Sep. 9, 2001.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to swimming pool lights and, more particularly, to a swimming pool light that is easily removable wherein a plurality of different light fixtures may be placed within the pool using a single connector for all light fixtures.
[0003] Currently water within a swimming pool is lighted by an incandescent light that is housed within a watertight fixture that is situated within a cavity that is within a pool wall, or a niche in a pool wall, below a water line. The cavity, or niche, is required in the wall of the pool because the incandescent light has a longitudinal length, wherein the niche is need to place the bulb so that it does not extend into the pool. Typically the niche is one of the greatest places for a leak to occur in a pool because of the size of the niche or area cut from the pool wall. Leaks occur because anytime you have a protrusion through a pool wall, such as a niche, the greater the protrusion, the greater the chance for a leak. The watertight fixture has an outer lens that may protrude slightly into the pool. When a new bulb is needed, the whole fixture is removed from the cavity, wherein a power cable supplying electricity to the light is long enough for the fixture to be safely positioned out of the pool water.
[0004] Typically, a clear, incandescent light bulb is placed in the fixture. If a colored effect is desired, such as blue, red or green, then a different color bulb is placed in the fixture. In another embodiment, typically used in spas, the outer lens is replaced with a colored lens, or a colored lens cover fits over the clear lens. In each of these situations, a user has to manually make a modification to the pool light to produce a desired color. However, if the user desires a continuously varying of colors where the intensity of the light is not lessened, such an option is not currently available.
[0005] Standard electrical wiring connects the watertight fixture to a 110-volt source. Providing a 110-volt source to such an underwater fixture presents an element of risk that many would prefer to avoid. Also, because of the illumination patterns of incandescent lamps, they frequently expose imperfections in the interior surface of the swimming pools as a consequence of the light's diffusion of light and the intensity of the light source.
[0006] It is known in the prior art to provide light emitting diode (“LED”) lighting assemblies for swimming pools, but such systems are frequently designed for aboveground pools and hot tubs. There are also known LED lighting assemblies for in-ground pools that house LED arrays that rotate to achieve variations of emitted color patterns. Typically such assemblies will employ a combination of red, green and blue LED arrays, which permit the generation of up to 26,000 colors, as is also well known in the art. For example, it is believed that U.S. Pat. No. 6,184,628 (the “'628 Patent”) teaches the use of predetermined arrays of a plurality of different color LED bulbs to replace an incandescent pool light, where the plurality of different color LED bulbs are wired in such a manner that the predetermined rays of a plurality of different colored LED bulbs activate at predetermined sequences for predetermined time intervals wherein the bulbs are encased in a lens. Even though LED bulbs are used, providing LED lighting fixtures with brightness to rival incandescent bulbs is still an issue, especially when not all of the LED bulbs are illuminated, as suggested in the '628 Patent. As is also evident with the '628 Patent, the '628 patent is disclosed for placement within a niche. Thus, removing the invention disclosed in the '628 Patent from the niche is just as cumbersome as removing an incandescent light bulb from a niche and its enclosure.
BRIEF SUMMARY OF THE INVENTION
[0007] The present invention is directed to a detachable light assembly for a swimming pool, spa or another body of water where the light source does not have to be placed in a niche formed in a wall of a container holding the body of water, and where the primary light is removed and a plurality of other light assemblies may be connected to a power source while underwater. Towards this end, a swimming pool light assembly for connecting a light to a side wall of a pool is provided where a pool light niche is not needed. The assembly includes an interchangeable light, and a watertight connector to deliver power and/or control signals to the light. A cable for providing power from a power source and/or a control signal from a controller to the light is also provided. The light is operable for connecting and disconnecting from the watertight connector while both the connector and the light are submerged in water.
[0008] In another preferred embodiment, an underwater light system is disclosed. The underwater light system comprises a submersible light that is interchangeable with other lights and has a connection end. A watertight connector is also provided that is operable to receive power and/or a control signal for delivery to the light. A power source for providing power to the light and/or a controller for providing a control signal to the light is also provided. A cable with for providing power from the power source and/or a control signal from the controller to the light is also part of the system. The light may be connected and disconnected from the watertight connector while both the connector and light are submerged in water.
[0009] In another preferred embodiment, a submersible light system for replacing a niche light system in swimming pools wherein a niche is already cut into a side of the swimming pool is disclosed. The system comprises a plate to fit within the niche comprising a hole formed therethrough the plate. A submersible light comprising a lens cover and a connection end is provided. A watertight connector to receive power and/or a control signal and to deliver power and/or a control signal to the light is also part of the system. A cable with a first end connected to the connector for providing power from a power source and/or a control signal from a controller to the light is also part of the system. The plate closes the niche and the light is operable for connecting and disconnecting from the watertight connector through the plate while both the connector and light are submerged in water.
BRIEF SUMMARY OF THE DRAWINGS
[0010] The invention itself, both as to organization and method of operation, may best be understood by reference to the following description in conjunction with accompanying drawings, in which like numbers represent parts throughout the drawings and in which:
[0011] [0011]FIG. 1 is a cross sectional view of a removable light assembly connected to a waterproof connector positioned in a side of a swimming pool;
[0012] [0012]FIG. 2 is a front view of the watertight connector and adapter illustrating a locking notch;
[0013] [0013]FIG. 3 is a perspective view of a watertight connector with a light wherein the connection end of the light is displayed;
[0014] [0014]FIG. 4 is an exemplary embodiment of the preferred invention configured to fit within a pool with an existing niche; and
[0015] [0015]FIG. 5 displays exemplary embodiments of various light assemblies configurations that may be attached to the waterproof connector; and
DETAILED DESCRIPTION OF THE INVENTION
[0016] With reference to the figures, exemplary embodiments of the invention will now be described. The scope of the invention disclosed is applicable to a plurality of uses. Thus, even though embodiments are described specifically to swimming pool light fixtures, the present invention is applicable to other uses or applications such as, but not limited to, spas, ponds, and man-made lakes. Additionally, other examples include uses in the area of architectural lighting such as interior and exterior lighting of residential homes, office complexes and/or other buildings. Similarly, the same or other embodiments may be used in landscaping, such as illuminating sidewalks, pools of water, waterfalls or any other area that needs to be illuminated, including underwater applications. Furthermore, though the present invention is disclosed specific to LED lights, other forms of lights, such as fiber optic lighting and laser lighting, but not limited to these three forms of lighting, are also applicable to the present invention. Finally, the present invention is illustrated primarily with respect for use with gunite swimming pools wherein certain aspects of the invention are specific to gunite pools. Those skilled in the art will readily recognize that a plurality of ways are available to implement the present invention depending on the type of pool the present invention is being applied to.
[0017] [0017]FIG. 1 is an exemplary embodiment of a cross-sectional view of a preferred embodiment of the present invention. The embodiment in FIG. 1 is specific to a pool made of gunite. As illustrated, an opening 9 is provided through a sidewall 12 of a container holding a body of water, such as a sidewall of a swimming pool. A pipe 10 is placed through the opening 9 . A power cable, or electrical conduit, 14 is fed through the pipe 10 and is connected to an underwater connector 16 . In a preferred embodiment, in addition to providing electrical power to a light fixture 20 through the power cable 14 , feeds are provided to connect the light 20 to a controller (not shown), which is used to control whether the light 20 is on or off, as well as to determine color patterns to be illuminated from the light 20 .
[0018] For a gunite pool, an adapter 22 is fitted into the pipe 10 and around the power cable 14 wherein the watertight connector 16 is fitted to the adapter 22 . In constructing the gunite pool, once the adapter 22 is placed within the opening 9 through the base wall 12 , gunite 25 is applied around the part of the adapter 22 that extends from the base wall 12 . In a preferred embodiment, the adapter 22 still has an edge that extends beyond the gunite 25 surface 32 . In another preferred embodiment, the edge does not extend beyond the gunite 25 surface 32 . In one preferred embodiment, at the area between the back surface 30 of a light 20 and the gunite 25 surface 32 of the pool, a foam insert (not shown) is positioned in this opening 40 prior to inserting the light 20 into the underwater connector 16 . The light assembly 20 is connected into the adapter 22 via connectors 42 , such as, in a preferred embodiment, by bolts, such as three bolts 42 .
[0019] In one embodiment, the bolts 42 engage respective receptacles 43 in the adapter 22 . In another preferred embodiment, connectors, such as bolts 42 , engage respective receptacles (not shown) in the swimming pool wall. In another preferred embodiment an adapter 22 and connector 16 are a single, integrated unit wherein the receptacles 43 are disclosed in this integrated unit. As illustrated in FIG. 2, the light 20 , connector 16 and/or adapter 22 will include an alignment pattern mark 45 , such as a notch 45 , wherein the light 20 may only be engaged into the connector 16 in one direction. The bolts 42 are tightened until a watertight seal is formed between the light 20 and the adapter 22 and/or connector 16 .
[0020] In a preferred embodiment, a watertight indicator 35 is provided, such as a reverse plunger, wherein when the light 20 is properly secured, the plunger 35 , which starts beneath the surface of the outer lens cover 33 of the light 20 , rises as the bolts 42 are tightened until the light 20 has achieved a secured watertight seal. When the watertight seal is achieved, the top of the plunger 35 is level with the top cover of the lens 33 or is flush with surface of the lens cover 33 .
[0021] As illustrated in FIG. 3, in a preferred embodiment, the end of the light or prongs 50 that engage the connector 16 extends from the back of the light and plugs into openings 52 in the connector 16 . In another preferred embodiment (not shown), the connector 16 has prongs that extend from the connector 16 and engages openings on the back of the light 20 . In another preferred embodiment (not shown), instead of providing bolts 42 , or other connectors, to secure the light 20 to the adapter 22 and/or connector 16 , the connector 16 is designed wherein the light 20 has prongs 50 on a back end that fit within openings 52 in the connector 16 and the light 20 is then rotated until the prongs 50 lock into the openings 52 of connector 16 and/or adapter 22 . In each embodiment, when the prongs 50 from the light 20 engage the openings 52 , or receptacles, of the connector 16 , the water is pushed out from the connector 16 ; thus, sealing the connection and forcing water from interfering with the connection of the light 20 to the power source and the controller provided through the connector 16 via the cable 14 . One skilled in the art will readily recognize a plurality of ways in which to connect the light 20 to the connector 16 and/or pool's side.
[0022] In another preferred embodiment, exemplarily illustrated in FIG. 4, where a niche 60 is already provided in the wall of a swimming pool, and a decision is made to use the present invention, a plate 62 is provided which fits within the niche 60 , in essence, closing off the niche 60 so that the light 20 will then fit on the plate 62 and the connector 16 and cable 14 are placed through an opening in the plate 62 . In one preferred embodiment illustrated in FIG. 4, instead of the plate 62 being positioned where the light 20 extends into the pool or body of water, the plate 62 is fixed further into the niche 60 and the light 20 is of a diameter wherein it fits within the niche 60 , so that the lens cover 33 of the light 20 is flush or is in the same plane as the surface of the pool. As discussed above, the connector 16 is still provided through the plate 62 ; however, the adapter 22 is not necessarily needed. Likewise, for other pools types, such as vinyl and fiberglass, the adapter 22 , described herein is not necessarily needed.
[0023] Thus, once the watertight connector 16 is properly secured and is in place, a user can easily exchange or remove the light 20 that is currently in place and replace it with a plurality of other lights 40 of varying sizes and shapes, as is exemplarily illustrated in FIG. 5, which illustrates a perspective view and side view of a plurality of lenses attached to a pool wall.
[0024] While the invention has been described in what is presently considered to be a preferred embodiment, many variations and modifications will become apparent to those skilled in the art. Accordingly, it is intended that the invention not be limited to the specific illustrated embodiment, but be interpreted within the full spirit and scope of the appended claims. | A swimming pool light assembly for connecting a light to a side wall of a pool where a pool light niche is not provided, said assembly comprises an interchangeable light, a watertight connector comprising a first end and a second end operable to deliver at least one of power and control signals to said light through said first end, and a cable with a first end connected to said connector for providing at least one of power from a power source and a control signal from a controller to said light, wherein said light is operable for connecting and disconnecting from said watertight connector while both said connector and said light are submerged in water. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. design application Ser. No. 29/467,935 filed concurrently on Sep. 25, 2013, which application is a continuation-in-part of International Application No. PCT/US2009/001442, filed Mar. 4, 2009 designating the United States and other countries, which is a continuation of U.S. application Ser. No. 12/137,482, filed Jun. 11, 2008, now U.S. Pat. No. 7,717,017 issued on May 18, 2010, the disclosures of which are hereby incorporated by reference in their entirety to provide continuity of disclosure to the extent such disclosures are not inconsistent with the disclosure herein.
FIELD OF THE INVENTION
This invention generally relates to tools and more particularly relates to hand tools and methods of manufacturing and using same.
BACKGROUND OF THE INVENTION
Conventional hand tools, such as conventional fingernail and toe nail clippers, have proven problematic to use, particularly when used by the elderly, arthritic individuals, stroke victims and others who have limited range of arm, wrist and hand movement.
More specifically, conventional fingernail and toe nail clippers have a spring handle that pivots about a fulcrum. Connected to the handle is a lever that is configured to downwardly press against the handle, so as to cause cutting edges formed on the handle to contact each other. However, the handle and lever must be in alignment with each other during the nail clipping operation to achieve efficient operation of the device. Movement of the handle and lever into alignment during the nail clipping operation requires extensive manipulation of the handle and lever and extensive dexterity on the part of the user. Such extensive manipulation and need for extensive dexterity is problematic for elderly persons, arthritic individuals, stroke victims and others having limited arm, wrist and hand movement.
As another example, with respect to surgical instruments, it is often necessary to perform surgery on difficult-to-reach areas of the human body without obstructing the surgeon's field of view. This is also true with respect to veterinarians who perform surgery on animals. Also, in the specific case of surgery, it is also often necessary for the surgeon to use one surgical instrument, such as scissors, to perform a clipping/cutting procedure on a body structure, while using another surgical instrument, such as forceps or clamps, to hold the body structure. These two surgical instruments typically have significantly different fixed configurations. Having to stock a multiplicity of surgical instruments in hospital inventory with significantly different fixed configurations for performing different surgical functions is inconvenient and costly.
As a further example, with respect to wire and bolt cutters, it is sometimes necessary to sever cables and bolts located in confined spaces and recesses. This may be necessary when performing machinery repair, remodeling/renovating buildings, rescue of persons trapped by fallen building structure and debris, and rescue of persons trapped in damaged automobiles due to a collision. Use of cable and bolt cutters having configurations with cutting edges in a permanent, fixed orientation can make such cutting operations more difficult.
Attempts have been made to address the considerations mentioned hereinabove with respect to the structure and use of hand tools. For example, U.S. Pat. No. 5,062,666 titled “Nail Clipper” issued Nov. 12, 1991, in the name of Jaw-Shiunn Tsay relates to an improved nail clipper.
According to the Tsay patent, the nail clipper comprises an elongate lever, a short upper body, a long lower body and a joint pin to assemble the lever and both the upper and the lower bodies together at their front sections, so that the lever can be pressed down to compress the upper body downward on the lower body. The nail clipper further comprises two opposed pairs of curved cutting edges provided on opposite sides of the upper and the lower bodies (see FIGS. 3, 4, 5 and 6 of the Tsay patent). The cutting edges are fixed at two positions, one position being perpendicular to the other position. This patent states that an advantage of the nail clipper is that the two pairs of cutting edges can easily clip nails on the other hand after finishing one hand.
However, the Tsay patent discloses that the cutting edges are fixed at two positions, one position being perpendicular to the other position. Fixing the cutting edges at two positions may nonetheless require a user to extensively manipulate the nail clipper to clip nails. Requiring the user to extensively manipulate the nail clipper to clip nails is inconvenient for the user.
Another attempt to address the considerations mentioned hereinabove with respect to the structure and use of hand tools is disclosed in U.S. Pat. No. 3,742,957 titled “Surgical Clamp” issued Jul. 3, 1973, in the name of Jack H. White. The White patent relates to surgical and like clamps.
According to the White patent, a clamp includes a set of jaws including a gripping portion and an actuating portion and pin means pivotally connecting the jaws for movement between open and closed positions within a first plane. A set of handles comprising crank arms are disposed and operable between the open and closed positions within a second plane. The second plane is mutually intersecting with the first plane and the crank arms are connected to the actuating portion of the jaws at the junctures of respective leg portions of the crank arms. As mentioned in the White patent, this connection comprises a hinge for infinite angular positioning of the first plane containing the jaws with respect to the second plane containing the crank arms. Also, the leg portions of the crank arms are pivotally joined as by a pin, which in the illustrated embodiment comprises a screw, to provide for opening and closing movement of the handles.
However, the White patent discloses that opening and closing movement of the handles is accomplished by adjustment of a screw (i.e., pin) that joins the handles. Only allowing opening and closing movement of the handles by means of a screw creates unnecessary delay in adjusting the clamp before surgery, readjusting the clamp during surgery, if necessary, and releasing the clamp after surgery because a screw driver is apparently needed to adjust the screw. Such a delay before, during and after a surgical procedure is undesirable.
Another attempt to address the considerations mentioned hereinabove with respect to the structure and use of hand tools is disclosed in U.S. Pat. No. 2,020,242 titled “Swivel Head Tool” issued Nov. 5, 1935, in the name of G. W. Geddes. The Geddes patent relates to tools in which the jaws may be placed in various angular positions relative to an operating handle system.
According to the Geddes patent, a bolt clipper embodying a jaw lever system and an actuating handle lever system are provided. The jaw levers can be adjusted to various angular positions relative to the plane of the handle levers so as to permit operating swinging movement of the jaws. For this purpose, joints embody mating spherical surfaces and tail portions of the jaw levers are provided with shallow recesses of spherical contour, which receive interposed balls on which at least of one of the parts turns (see column 2, lines 15-37 of the Geddes patent). This patent also discloses that handle members are apparently pivotally mounted by means of a screw-like pin.
However, although the Geddes patent discloses handle members that are pivotally mounted, this patent apparently requires adjustment of a screw-like pin in order to return the handle members to their default position. Requiring adjustment of the screw-like pin in order to return the handle members to their default position is inconvenient for the user because a screw driver is apparently needed to adjust the screw-like pin.
Although the approaches recited hereinabove disclose various configurations of hand tools, the approaches recited hereinabove do not appear to disclose the invention described and claimed hereinbelow.
SUMMARY OF THE INVENTION
The present invention addresses the shortcomings of the prior art approaches mentioned hereinabove by providing a suitable hand tool, and method of manufacturing and using same.
According to a first embodiment of the present invention, the hand tool comprises a handle assembly that, in use, is oriented in a y-axis plane. The handle assembly is sized and contoured to be manipulated by hand. In this regard, the handle assembly includes a generally smooth, arcuate-shaped upper handle member and a generally smooth, arcuate-shaped lower handle member disposed opposite the upper handle member. In this manner, the upper handle member and the lower handle member are disposed in the same y-axis plane for grasping by the user. In addition, the upper handle member and the lower handle member are pivotally linked or pivotally joined together by a linkage bolt that allows pivoting action of the handle members in the y-axis plane. That is, the upper and lower handle members pivot toward each other to a closed position when the user grasps and simultaneously applies manual pressure to the upper and lower handle members. A biasing member, which may be in the form of a leaf spring, is interposed between the handle members for automatically biasing the handle members away from each other in order to return the handle members to their default open position after hand pressure is released.
The hand tool also comprises a coupler assembly including an upper coupler and a lower coupler. The upper coupler includes an articulating upper heim joint and the lower coupler includes an articulating lower heim joint. The upper heim joint is connected to the upper handle member and the lower heim joint is connected to the lower handle member. The upper and lower heim joints are each provided with threaded shanks for threadably engaging their respective upper and lower handle members. In this manner, the upper and lower heim joints are fixedly attached to their respective upper and lower handle members. As known in the art, a heim joint (i.e., also referred to in the art as a rose joint, rod end bearing, or heim bearing) allows multi-directional, such as side-to-side (i.e., rotational or swiveling), and tilting, substantially frictionless movement of a component connected to it without breaking of the component.
As contemplated by the invention, a component comprising a tool head is connected to the upper and lower heim joints. The tool head can be fingernail or toe nail clipper blades, surgical clamp jaws, bolt cutter blades or other tool head. For example, with respect to blade tools (e.g., fingernail or toe nail clippers, bolt cutters), the tool head comprises an upper blade tool pivotally connected to the upper heim joint and a lower blade tool pivotally connected to the lower heim joint. A pivot pin joins the upper blade tool and the lower blade tool. In this manner, the pivot pin, upper heim joint and lower heim joint cooperate to allow simultaneous side-to-side (i.e., rotational or swiveling) movement of the upper and lower blade tools in addition to allowing closing and opening of the blade tools. The user manually moves the blade tools to a desired side-to-side (i.e., rotated, swiveled) and/or tilted orientation for operating on a work piece. When the user grasps and simultaneously applies manual pressure to the upper and lower handle members, the upper and lower handle members pivot toward each other and lock in position. As the upper and lower handle members pivot toward each other, the upper and lower blade tools also pivot toward each other due to the previously mentioned interconnection of the blade tools with the handle members. As the upper and lower blade tools pivot toward each other in this manner, the upper blade tool and the lower blade tool close. Conversely, as manual pressure is released, the upper and lower handle members automatically pivot away from each other due to presence of the biasing member interposed between them. Thus, as the upper and lower handle members pivot away from each other, the upper blade tool and the lower blade tool open, which is the default position of the device. In this manner, manual actuation of the handle members in cooperation with the heim joints that interconnect the tool head assembly and the handle assembly allow opening and closing of the upper and lower blade tools.
The upper and lower heim joints allow their respective upper and lower blade tools to swivel or rotate side-to-side at least 180 degrees in the x-plane and tilt a limited amount (e.g., about 30°) in the x and y axes planes in order to conveniently position the upper and lower blade tools at a desired location on the work piece. As previously mentioned, means are provided for locking the angular (i.e., rotational, swivel or side-to-side) and tilted position of the upper and lower blade tools. In other words, once the upper and lower blade tools are positioned at the desired location on the work piece, the handle members are closed in order to lock the upper and lower blade tools in their angular position and to actuate the upper and lower blade tools, so that the upper and lower blade tools close, as previously mentioned, to cut the work piece.
Thus, the upper blade tool, lower blade tool, pivot pin, upper heim joint, and lower heim joint cooperate to allow the upper blade tool and lower blade tool to simultaneously swivel or rotate at least 180 degrees in the x-axis plane and tilt a limited amount (i.e., about 30°) in the x and y axes planes for positioning the upper blade tool and lower tool at the desired location for operating on the work piece.
In this first embodiment of the invention, the tool head is detachable from the heim joints by means described in detail hereinbelow. This allows decoupling of the tool head from the heim joints, so that different types of tool heads and various sizes of the same type of tool head can be interchanged. Also, providing for detachment or decoupling of the tool head from the heim joints allows replacement of a worn tool head. Thus, the hand tool of the present invention is versatile and accommodates tool heads required for different applications.
Therefore, the 180 degree rotational (i.e., swivel) feature and the tilting feature allow the hand tool of the first embodiment of the invention to obtain a variable angle of attack on a work piece. Obtaining such a variable of attack allows the hand tool to be conveniently manipulated in a manner that is particularly useful for elderly persons, arthritic individuals, stroke victims and others who have a limited range of arm, wrist and hand movement. The variable angle of attack also allows the hand tool to be conveniently manipulated in a manner that is particularly useful for performing surgical procedures on structures located in difficult-to-reach areas of the human body without obstructing the surgeon's field of view. In addition, the variable angle of attack allows the hand tool to be conveniently manipulated in a manner for cutting cables and bolts located in difficult to access, confined spaces.
A second embodiment of the invention is strictly in the form of a fingernail or toe nail clipper and has some features similar to the features of the first embodiment of the invention. In this regard, the second embodiment of the invention comprises a pair of handle members each including a relatively thin, arcuate-shaped outer shell matingly mounted on an arcuate-shaped inner supporting frame member. The outer shell covers the frame member, so that the frame member is not substantially visible. The outer shell may be formed from an aesthetically pleasing, decorative polymer plastic material, or other aesthetically pleasing material, and the frame member may be a light weight metal, metal alloy or other light-weight composition, so that the nail clipper may be easily carried in pocket or purse. Pair of oppositely disposed, pivotable cutting edges are interposed between distal end portions of the handle members and are generally concealed from view by the distal end portions of the handle members when viewed from the top or bottom of the device. A pair of heim joints interconnects respective ones of the pair of handle members with respective ones of the pair of cutting edges. The heim joints allow side-to-side rotational or swiveling movement of the cutting edges through an angle of about 180°. The upper handle member and the lower handle member are pivotally joined together by a pivot pin that allows pivoting action of the handle members in the y-axis plane. The upper and lower handle members pivot toward each other to a closed position when the user grasps and simultaneously applies manual pressure to the upper and lower handle members. The cutting edges are simultaneously locked in position and cut the fingernails or toe nails of the user when hand pressure is applied to close the handle members. A biasing member, which may be in the form of a torsion spring, is interposed between the handle members for biasing the handle members to their open default position when hand pressure is released by the user.
Therefore, the 180 degree side-to-side (i.e., rotational or swivel) movement feature of the cutting edges belonging to this second embodiment of the invention allows the device to obtain a variable angle of attack, so that fingernails and toe nails can be conveniently clipped by elderly persons, arthritic individuals, stroke victims and others who have a limited range of arm, wrist and hand movement.
According to an aspect of the present invention, there is provided a hand tool comprising a handle assembly oriented in a first plane and sized for hand manipulation; a tool head assembly coupled to the handle assembly for operating on a work piece in response to hand manipulation of the handle assembly; and at least one heim joint coupler interconnecting the handle assembly and the tool head assembly for rotating the tool head assembly to a selected angle relative to the handle assembly.
According to another aspect of the present invention, there is provided a hand tool, comprising: a handle assembly including a pair of handles oriented in a first plane and sized for hand manipulation; a tool head assembly coupled to the handle assembly for operating on a work piece in response to hand manipulation of the pair of handles; and at least one heim joint coupler interconnecting the handle assembly and the tool head assembly for rotating the tool head assembly to a selected angle relative to the handle assembly, so that the tool head assembly is oriented to operate on the work piece at the selected angle.
According to yet another aspect of the present invention there is provided a method of manufacturing a hand tool, comprising the steps of: providing a handle assembly; coupling a tool head assembly to the handle assembly; and interconnecting the handle assembly and the tool head assembly to at least one heim joint coupler.
A feature of the present invention is the provision of a tool head assembly coupled to a handle assembly for operating on a work piece in response to hand manipulation of the handle assembly, the tool head assembly being adapted to operate on the work piece at a selected angle.
Another feature of the present invention is the provision of at least one heim joint coupler interconnecting the handle assembly and the tool head assembly.
In addition to the foregoing, various other method and/or device aspects and features are set forth and described in the teachings, such as text (e.g., claims and/or detailed description) and/or drawings of the present invention.
The foregoing is a summary and thus may contain simplifications, generalizations, inclusions, and/or omissions of detail. Consequently, those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described hereinabove, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be more fully understood by reference to the detailed description in conjunction with the following figures, wherein:
FIG. 1 is a view in perspective of a first embodiment hand tool including a first embodiment tool head assembly configured as a fingernail or toe nail clipper;
FIG. 2 is a rear view in elevation of the first embodiment hand tool;
FIG. 3 is a front view in elevation of the first embodiment hand tool;
FIG. 4 is a right side view in elevation of the first embodiment hand tool;
FIG. 4A is a fragmentary view in elevation of the right side of the first embodiment hand tool;
FIG. 5 is a left side view in elevation of the first embodiment hand tool, the first embodiment hand tool being shown in an open position;
FIG. 5A is a left side view in elevation of the first embodiment hand tool, the first embodiment hand tool being shown in a closed position;
FIG. 6 is a partially exploded view of the first embodiment hand tool;
FIG. 7 is a top plan view of the first embodiment hand tool;
FIG. 8 is a bottom plan view of the first embodiment hand tool;
FIG. 9 is a right side view in elevation of a detached first embodiment tool head assembly configured as a fingernail or toe nail clipper;
FIG. 10 is a right side view in elevation of a detached second embodiment tool head assembly configured as a surgical clamp;
FIG. 11 is a right side view in elevation of a detached third embodiment tool head assembly configured as a cable/bolt cutter;
FIG. 12 is a view in perspective of a second embodiment hand tool including a tool head assembly configured as a fingernail or toe nail clipper, the second embodiment hand tool being shown in an open position;
FIG. 13 is a front view in elevation of the second embodiment hand tool;
FIG. 14 is a rear view in elevation of the second embodiment hand tool;
FIG. 15 is a right side view in elevation of the second embodiment hand tool;
FIG. 16 is a left side view in elevation of the second embodiment hand tool;
FIG. 16A is a fragmentary view in elevation of a distal end portion of the second embodiment hand tool;
FIG. 17 is a top plan view of the second embodiment hand tool;
FIG. 18 is a bottom plan view of the second embodiment hand tool;
FIG. 18A is a view in elevation of the second embodiment hand tool in a closed position;
FIG. 19 is an exploded view of the second embodiment hand tool; and
FIG. 20 is a flowchart showing an illustrative method of manufacturing the first and second embodiments of the hand tool.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from either the spirit or scope of the invention.
In addition, the present patent specification uses formal outline headings for clarity of presentation. However, it is to be understood that the outline headings are for presentation purposes, and that different types of subject matter may be discussed throughout the application (e.g., device(s)/structure(s) may be described under process(es)/operations heading(s) and/or process(es)/operations may be discussed under structure(s)/process(es) headings; and/or descriptions of single topics may span two or more topic headings). Hence, the use of the formal outline headings is not intended to be in any way limiting.
Therefore, with reference to FIGS. 1 , 2 and 3 , there is shown a first embodiment hand tool, generally referred as 1000 , for operating on a work piece (not shown). In the exemplary embodiment illustrated, hand tool 1000 is a fingernail or toe nail clipper for clipping or cutting fingernails and toe nails of a user (also not shown). However, it will be appreciated that hand tool 1000 is not limited to the configuration of a fingernail or toe nail clipper. Rather, hand tool 1000 may be in the configuration of other types of hand tools, as well, such as clamps and bolt cutters.
Referring again to FIGS. 1 , 2 and 3 , hand tool 1000 comprises a first embodiment hand held tool mount or handle assembly 1010 shown oriented in a y-axis or first plane. Handle assembly 1010 , which is sized for hand manipulation or grasping by the user, includes a generally smooth, contoured, arcuate-shaped upper handle member 1020 and a generally smooth, contoured, arcuate-shaped lower handle member 1030 disposed in the first plane opposite upper handle member 1020 . The contoured or arcuate shape of upper handle member 1020 and lower handle member 1030 facilitates grasping thereof by the user of hand tool 1000 . Upper handle member 1020 defines a proximal end portion 1032 a and a distal end portion 1032 b for reasons recited hereinbelow. Similarly, lower handle member 1030 defines a proximal end portion 1035 a and a distal end portion 1035 b for reasons recited hereinbelow. The handle assembly 1010 is also provided with a resilient biasing member in the form of an elongate leaf spring 1040 for reasons provided hereinbelow. In this regard, leaf spring 1040 has a unitary construction that includes a central straight segment portion 1050 , which is disposed between an upper straight portion 1050 a and a lower rounded or curved end portion 1050 b . Upper straight portion 1050 a is positioned generally intermediate proximal end portion 1032 a and distal end portion 1032 b of upper handle member 1020 . Lower rounded or curved end portion 1050 b is positioned generally intermediate proximal end portion 1035 a and distal end portion 1035 b of lower handle member 1030 .
Still referring to FIGS. 1 , 2 and 3 , in order to hold the handle members 1020 / 1030 apart, lower rounded or curved end portion 1050 b of leaf spring 1040 is mounted within a lower handle member cutout 1060 by a mounting or spring pin indicated generally at 1070 . Cutout 1060 is disposed at an inner rearward surface area of lower handle member 1030 in a manner that allows leaf spring 1040 to be disposed at an inclined angle between upper handle member 1020 and lower handle member 1030 . The opposite end of leaf spring 1040 , which terminates in upper straight portion 1050 a , permits the opposite or upper straight portion 1050 a to rest in engagement with an inner surface area of upper handle member 1020 . In short, leaf spring 1040 is wedged between upper handle member 1020 and lower handle member 1030 to provide a return force when the two handle members 1020 / 1030 are manually squeezed together by the user, such as in the direction of directional arrows 1075 a and 1075 b (see FIG. 5A ).
Referring again to FIGS. 1 , 2 , and 3 , upper handle member 1020 and lower handle member 1030 are pivotably connected to each other on an axis defined by a mounting or linkage bolt 1080 and are held apart from one another, in a default position, by the previously mentioned leaf spring 1040 . Linkage bolt 1080 therefore facilitates holding the two handle members 1020 / 1030 pivotally together. The previously mentioned return force is a force sufficient to cause the two handle members 1020 / 1030 to move pivotally away from one another about the axis defined by mounting or linkage bolt 1080 when handle members 1020 / 1030 are released by the user, so that handle members 1020 / 1030 return to their default or open positions as best seen in FIG. 1 . Although leaf spring 1040 of a particular configuration is illustrated, it should be understood by those skilled in the art that other suitable biasing or spring means may be utilized, such as a coiled compression spring (not shown) or other suitable spring means.
As shown in FIGS. 1 , 2 and 3 , hand tool 1000 further includes a heim joint coupler assembly [THE HANDLE ASSEMBLY WAS ALREADY CALLED A TOOL MOUNT] indicated generally at 1090 . The coupler assembly 1090 includes an upper mount or upper coupler in the form of an articulating upper heim joint 1100 . Coupler assembly 1090 further includes a lower mount or lower coupler in the form of an articulating lower heim joint 1110 , [WHEN YOU ARE GOING TO DESCRIBE DIFFERENT ASSEMBLY COMPONENTS YOU SHOULD SEPARATE THE REFERENCE CHARACTERS BY AT LEAST 100 UNITS—THIS ALLOWS YOU TO KEEP UPPER ASSEMBLY COMPONENT TOGETHER AND LOWER ASSEMBLY COMPONENT TOGETHER WHICH ALSO ALLOWS THE DRAWING PARTS TO BE MORE EASILY IDENTIFIED] Upper heim joint 1100 is threadably attached to distal end portion 1032 b of upper handle member 1020 by means of an elongate, externally threaded upper shank portion 1120 that is received in an internally threaded upper bore or hole 1130 formed in distal end portion 1032 b . Similarly, lower heim joint 1110 is threadably attached to distal end portion 1035 b of lower handle member 1030 by means of an elongate, externally threaded lower shank portion 1140 that is received in an internally threaded lower bore or hole 1150 formed in distal end portion 1035 b . Thus, upper shank portion 1120 is threadably received in upper hole 1130 and lower shank portion 1140 is threadably received in lower hole 1150 for coupling shank portions 1120 / 1140 to handle members 1020 / 1030 , respectively. However, shank portions 1120 / 1140 and holes 1130 / 1150 need not be threaded; rather, shank portions 1120 / 1140 and holes 1130 / 1150 may be smooth and sized for allowing coupling of shank portions 1120 / 1140 to handle members 1020 / 1030 by means of a press-fit.
Referring to FIGS. 1 , 4 , 4 A, 5 , 5 A and 6 , upper heim joint 1100 comprises an annular upper casing 1160 integrally attached to upper shank portion 1120 . Upper casing 1160 defines an opening 1165 therethrough for reasons provided hereinbelow. In addition, upper casing 1160 may have a generally spherical interior (not shown) contoured for slidably, matingly receiving a spherical upper ball swivel 1170 , such that upper ball swivel 1170 is slidably retained within upper casing 1160 . Upper ball swivel 1170 defines an upper ball hole 1180 (see FIG. 6 ) centrally therethrough for reasons provided hereinbelow. In this manner, upper ball swivel 1170 is capable of multi-directional, slidable movement within upper casing 1160 . In other words, upper ball swivel 1170 is capable of side-to-side, rotational, or swivel movement in the horizontal x-axis plane as illustrated by directional arrow 1182 (see FIG. 1 ). In addition, upper ball swivel 1170 is capable of tilting movement in the y-axis plane as illustrated by directional arrow 1184 (see FIGS. 1 and 5A ) as well as tilting movement in the x-axis plane as illustrated by directional arrow 1186 (see FIG. 1 ).
Referring again to FIGS. 1 , 4 , 4 A, 5 , 5 A and 6 , lower heim joint 1110 comprises an annular lower casing 1190 integrally attached to lower shank portion 1140 . Lower casing 1190 defines a lower casing opening 1195 therethrough for reasons provided hereinbelow. In addition, lower casing 1190 may have a generally spherical interior (not shown) contoured for slidably, matingly receiving spherical lower ball swivel 1200 , such that lower ball swivel 1200 is slidably retained within lower casing 1190 . Lower ball swivel 1200 defines a lower ball hole 1210 (see FIG. 6 ) centrally therethrough for reasons provided hereinbelow. In this manner, lower ball swivel 1200 is capable of multi-directional, slidable movement within lower casing 1190 . In other words, lower ball swivel 1200 is capable of side-to-side, rotational, or swivel movement in the horizontal x-axis plane as illustrated by previously mentioned directional arrow 1182 (see FIG. 1 ). In addition, lower ball swivel 1200 is capable of tilting movement in the y-axis plane as illustrated by directional arrow 1205 (see FIGS. 1 and 5A ) as well as tilting movement in the x-axis plane as illustrated by previously mentioned directional arrow 1186 (see FIG. 1 ). As described fully hereinbelow, it will be appreciated that ball swivels 1170 / 1200 will rotate and tilt in unison as will be explained in greater detail hereinafter.
Referring to FIGS. 1 , 3 , 4 , 4 A, 5 , 5 A and 6 , to provide hand tool 1000 with the functionality noted hereinabove, hand tool 1000 further includes a replaceable, first embodiment tool head assembly, generally referred to as 1220 , for clipping fingernails and toe nails of the user of hand tool 1000 . In other words, tool head assembly 1220 , which is coupled to handle assembly 1010 by means of coupler assembly 1090 , is capable of operating on (i.e., clipping) the fingernails and toe nails (i.e., the work piece) of the user in response to hand manipulation of handle assembly 1010 , as described in detail presently. In this regard, tool head assembly 1220 generally includes an upper tool member 1230 and a lower tool member 1240 both disposed in the y-axis plane, lower tool member 1240 being oriented opposite to and coincident with upper tool member 1230 . Lower tool member 1240 includes a lower tool member [IT IS ALWAYS BETTER TO USE NAMES AS OPPOSED TO FIRST, SECOND, ETC.] pivoting portion 1250 a and upper tool member 1230 includes an upper tool member pivoting portion 1250 b (see FIG. 3 ). The lower tool member pivoting portion 1250 a and upper tool member pivoting portion 1250 b are pivotably interconnected by a pivot pin 1260 . Thus, the pivotable interconnection of first pivoting portion 1250 a and second pivoting portion 1250 b allow lower tool member 1240 and upper tool member 1230 to pivot about pivot pin 1260 for reasons provided hereinbelow.
Referring yet again to FIGS. 1 , 4 , 4 A, 5 , 5 A and 6 , upper tool member 1230 has a unitary construction and includes an upper jaw 1270 in the form of an upper blade tool having an upper tool elongate front cutting edge portion 1280 . Similarly, lower tool member 1240 has a unitary construction and includes a lower jaw 1290 opposite upper jaw 1270 . The lower jaw 1290 is in the form of a lower blade tool having a lower tool elongate front cutting edge portion 1300 . Fingernails and toe nails of the user are clipped or cut when cutting edge portions 1280 / 1300 are brought to bear against each in the manner described hereinbelow.
Still referring to FIGS. 1 , 4 , 4 A, 5 , 5 A and 6 , upper tool member 1230 includes an upper arm portion 1304 a and a lower arm portion 1304 b . Lower arm portion 1304 b is disposed opposite of and coincident with upper arm portion 1304 a . Upper arm portion 1304 a defines an internally threaded upper arm bore 1306 a therethrough and lower arm portion 1304 b defines an internally threaded lower arm bore 1306 b therethrough (see FIG. 4A ), upper arm bore 1306 a and lower arm bore 1306 b are aligned with previously mentioned upper ball hole 1180 defined by the upper ball swivel 1170 . Similarly, lower tool member 1240 includes a third or another upper arm portion 1308 a and a fourth or another lower arm portion 1308 b . The lower tool member lower arm portion 1308 b is disposed opposite of and coincident with the lower tool member upper arm portion 1308 a . The lower tool upper arm portion 1308 a defines an internally threaded lower tool upper arm bore 1309 a therethrough and lower tool lower arm portion 1308 b defines an internally threaded lower tool lower arm bore 1309 b therethrough (see FIG. 4A ). The lower tool lower arm bore 1309 a and the lower tool upper arm bore 1309 b are aligned with previously mentioned lower ball hole 1210 defined by lower ball swivel 1200 . Moreover, upper arm portion 1304 a and lower arm portion 1304 b of the upper tool member 1230 are spaced apart, so as to define a space 1310 therebetween for receiving upper heim joint 1100 thereinto. Similarly, upper arm portion 1308 a and lower arm portion 1308 b of the lower tool member 1240 are space apart, so as to define another space 1320 therebetween for receiving lower heim joint 1110 thereinto. Spaces 1310 and 1320 are sized to accommodate presence of heim joints 1100 / 1110 therein and allow tool head assembly 1220 to freely rotate in the x-axis plane without obstruction. In this regard, it will be appreciated by those skilled in the arm that ball swivels 1170 / 1200 will rotate and tilt in unison and to a like extent due to their interconnection by means of the upper tool member 1230 , the lower tool member 1240 and the pivot pin 1260 (see FIGS. 1 , 4 , 4 A, 5 and 5 A).
Although not critical, it is nonetheless important that tool head assembly 1220 be detachably coupled to coupler assembly 1090 , so that different types of tool head assemblies 1220 and various sizes of the same type of tool head assembly 1220 can be interchanged. Also, providing for detachment of tool head assembly 1220 from coupler assembly 1090 allows replacement of a worn tool head assembly 1220 . Thus, hand tool 1000 is versatile and accommodates tool head assemblies required for different applications.
Referring again to FIGS. 1 , 4 , 4 A, 5 , 5 A and 6 , the manner in which tool head assembly 1220 is detachably coupled to coupler assembly 1090 will now be described. In this regard, an upper connecting member, such as externally threaded upper tool screw-bolt 1330 (see FIG. 6 ), is caused to threadably engage internally threaded upper arm bore 1306 a and internally threaded lower arm bore 1306 b as upper tool screw-bolt 1330 extends through upper arm bore 1306 a , upper ball hole 1180 defined by upper ball swivel 1170 and into lower arm bore 1306 b . In this manner, upper heim joint 1100 is retained within space 1310 as upper tool member 1230 rotates and/or tilts.
Similarly, a lower connecting member, such as externally threaded lower tool screw-bolt 1340 , is caused to threadably engage internally threaded lower arm bore 1309 b and internally threaded upper arm bore 1309 a as lower tool screw-bolt 1340 extends through upper arm bore 1309 b , lower ball hole 1210 defined by lower ball swivel 1200 and into upper arm bore 1309 a . In this manner, lower heim joint 1110 is retained within space 1320 as lower tool member 1240 rotates and/or tilts. Also, in this manner, upper tool member 1230 and lower tool member 1240 are detachably coupled to upper heim joint 1100 and lower heim joint 1110 , respectively, due to use of screw bolts 1330 / 1340 . It should be appreciated that upper tool member 1230 and lower tool member 1240 will rotate and tilt in unison and to a like extent due to their interconnection by means of pivot pin 1260 and due to use of upper screw-bolt 1330 and lower screw-bolt 1340 , as described hereinabove. Detaching or decoupling of upper tool member 1230 and lower tool member 1240 from upper heim joint 1100 and lower heim joint 1110 , respectively, is accomplished by reversing the above-described steps for coupling upper tool member 1230 and lower tool member 1240 to upper heim joint 1100 and lower heim joint 1110 .
As previously indicated, movement of tool head assembly 1220 is multi-directional because tool head assembly 1220 is adapted to rotate or swivel in the x-axis plane and tilt in both the x-axis and y-axis planes. Such rotation and tilting is provided by presence of upper ball swivel 1170 that belongs to upper heim joint 1100 and lower ball swivel 1200 that belongs to lower heim joint 1110 . However, for the sake of brevity, the description hereinbelow is directed only to rotation or swiveling of tool head assembly 1220 in the x-axis plane, it being understood that tool head assembly 1220 is adapted to swivel and tilt in the x-axis plane and only tilt in the y-axis plane.
Therefore, referring to FIGS. 1 , 7 and 8 , tool head assembly 1220 is adapted to move side-to-side (i.e., rotate or swivel) in the x-axis plane to a user selected angle less than or equal to an angle theta “Ø” of about 180 degrees. Tool head assembly 1220 is capable of rotating in the x-axis plane due to presence of upper ball swivel 1170 and lower ball swivel 1200 , as previously mentioned. Such side-to-side, rotational or swiveling movement of tool head assembly 1220 in the x-axis plane is accomplished by hand.
Turning now to FIGS. 9 , 10 and 11 , various tool head assembly embodiments are there shown. As previously mentioned, detachable first embodiment tool head assembly 1220 comprises upper jaw 1270 having upper tool front cutting edge 1280 and lower jaw 1290 having lower tool front cutting edge 1300 for cutting or clipping fingernails or toe nails of the user when upper tool cutting edge 1280 and lower tool front cutting edge 1300 are brought to bear against each other.
A detachable second embodiment tool head assembly, generally referred to as 1350 , comprises an upper jaw 1360 having an upper jaw clamping extension 1370 and a lower jaw 1380 having a lower jaw clamping extension 1390 . Upper jaw 1360 and lower jaw 1380 of second embodiment tool head assembly 1350 are capable of pivoting about pivot pin 1260 in a manner substantially similar to the pivoting action of upper jaw 1270 and lower jaw 1290 of first embodiment tool head 1220 . Upper jaw clamping extension 1370 and lower jaw clamping extension 1390 are capable of capturing and holding a work piece (not shown) therebetween, such as tissue being operated upon during a surgical procedure.
A detachable third embodiment tool head assembly, generally referred to as 1400 , comprises an upper jaw 1410 having a upper sharpened edge 1420 and a lower jaw 1430 having a lower sharpened edge 1440 . Upper jaw 1410 and lower jaw 1430 of second embodiment tool head assembly 1440 are capable of pivoting about pivot pin 1260 in a manner substantially similar to the pivoting action of upper jaw 1270 and lower jaw 1290 of first embodiment tool head 1220 . Upper sharpened edge 1420 and lower sharpened edge 1440 are capable of shearing a work piece (not shown) therebetween, such as a bolt or cable.
Turning now to FIGS. 12 , 13 and 14 , there is shown a second embodiment hand tool, generally referred to as 1450 . The second embodiment hand tool 1450 comprises a second embodiment hand held tool mount or handle assembly 1460 shown oriented in a y-axis or first plane. Handle assembly 1460 , which is sized for hand manipulation or grasping by the user, comprises an upper handle member 1470 that includes a generally smooth, contoured, arcuate-shaped upper shell 1472 that matingly covers an arcuate-shaped upper frame member 1475 . Upper frame member 1475 has a proximal end portion 1477 a and a distal end portion 1477 b . Handle assembly 1460 further comprises a lower handle member 1480 that includes a generally smooth, contoured, arcuate-shaped lower shell 1482 that matingly covers an arcuate-shaped lower frame member 1484 . Lower frame member 1484 has a proximal end portion 1485 a and a distal end portion 1485 b . Lower handle member 1480 is disposed in the first plane opposite upper handle member 1470 . The contoured or arcuate shape of upper shell 1472 that belongs to upper handle member 1470 and the contoured or arcuate shape of lower shell 1482 that belongs to lower handle member 1480 facilitates grasping thereof by the user of hand tool 1450 . Frame members 1475 / 1484 provide support for shells 1472 / 1482 and serves other useful functions, as described hereinbelow. Upper handle member 1470 defines a proximal end portion 1486 a and a distal end portion 1486 b for reasons recited hereinbelow. Similarly, lower handle member 1480 defines a proximal end portion 1488 a and a distal end portion 1488 b for reasons recited hereinbelow. Hand tool 1450 is also provided with a resilient biasing member in the form of a coiled torsion spring 1490 for reasons provided hereinbelow. Torsion spring 1490 is disposed between upper handle member 1470 and lower handle member 1480 . Torsion spring 1490 is configured to have a pair of protruding ends 1492 a / 1492 b thereof in contact with upper handle member 1470 and lower handle member 1480 , respectively, for providing a biasing force against upper handle member 1470 and lower handle member 1480 . In this manner, torsion spring 1490 provides a biasing return force to maintain upper handle member 1470 and lower handle member 1480 in an open default position, as shown, Upper handle member 1470 and lower handle member 1480 are maintained in the open default position until the user simultaneously applies manual pressure to upper handle member 1470 and lower handle member 1480 to move upper handle member 1470 and lower handle member 1480 closer together. This act by the user places torsion spring 1490 in compression. Upon release of the manual pressure by the user, torsion spring 1490 is released from its compressed state and expands, so that handle members 1470 / 1480 return to their open, default positions.
Referring again to FIGS. 12 , 13 and 14 , upper handle member 1470 and lower handle member 1480 are pivotably connected to each other on an axis defined by a mounting or linkage bolt 1500 (see FIG. 19 ) and are held apart from one another, in a default position, by the previously mentioned torsion spring 1490 . Linkage bolt 1500 therefore facilitates holding the two handle members 1470 / 1480 pivotally together. Although torsion spring 1490 of a particular configuration is illustrated, it should be understood by those skilled in the art that other suitable biasing or spring means may be utilized, such as a coiled compression spring (not shown) or other suitable spring means.
Referring to FIGS. 15 and 16 , hand tool 1450 generally includes a tool mount or coupler assembly indicated generally at 1510 . The coupler assembly 1510 includes an upper mount or upper coupler in the form of an articulating upper heim joint, generally referred to as 1520 . Coupler assembly 1510 further includes a lower mount or lower coupler in the form of an articulating lower heim joint, generally referred to as 1530 . Upper heim joint 1520 is threadably attached to distal end portion 1477 b of upper frame member 1475 by means of an elongate, externally threaded upper shank portion 1540 (see FIG. 19 ) that is received in an internally threaded upper bore or hole (not shown) formed in distal end portion 1477 b . Similarly, lower heim joint 1530 is threadably attached to distal end portion 1485 b of lower frame member 1484 by means of an elongate, externally threaded lower shank portion 1550 that is received in an internally threaded lower bore or hole (not shown) formed in distal end portion 1485 b . Thus, upper shank portion 1540 is threadably received in the upper hole and lower shank portion 1550 is threadably received in the lower hole for coupling shank portions 1540 / 1550 to handle members 1470 / 1480 , respectively. However, shank portions 1540 / 1550 and their respective holes need not be threaded; rather, shank portions 1540 / 1550 and their respective holes may be smooth and sized for allowing coupling of shank portions 1540 / 1550 to handle members 1470 / 1480 by means of a press-fit.
Referring to FIGS. 15 , 16 , 17 , 18 and 19 , upper heim joint 1520 comprises an annular upper casing 1560 integrally attached to upper shank portion 1540 . Upper casing 1560 defines an opening 1565 therethrough for reasons provided hereinbelow. In addition, upper casing 1560 may have a generally spherical interior (not shown) contoured for slidably, matingly receiving a spherical upper ball swivel 1570 , such that upper ball swivel 1570 is slidably retained within upper casing 1560 . Upper ball swivel 1570 defines a hole 1575 (see FIG. 19 ) centrally therethrough for receiving a smooth upper connector pin 1576 about which upper ball swivel 1570 freely rotates in the x-plane. Connector pin 1576 also interconnects upper ball swivel 1570 to upper frame member 1475 and to an upper tool member 1600 as will be explained hereinafter in greater detail. In this manner, upper ball swivel 1570 is capable of multi-directional, slidable movement within upper casing 1560 . In other words, upper ball swivel 1570 is capable of side-to-side, rotational, or swivel movement in the horizontal x-axis plane as illustrated by directional arrow 1577 (see FIG. 12 ).
Referring again to FIGS. 15 , 16 , 17 , 18 and 19 , lower heim joint 1530 comprises an annular lower casing 1580 integrally attached to lower shank portion 1550 . Lower casing 1580 defines an opening 1585 therethrough for reasons provided hereinbelow. In addition, lower casing 1580 may have a generally spherical interior (not shown) contoured for slidably, matingly receiving a spherical lower ball swivel 1590 , such that lower ball swivel 1590 is slidably retained within lower casing 1580 . Lower ball swivel 1590 defines a hole 1595 (see FIG. 19 ) centrally therethrough for receiving a smooth lower connector pin 1596 about which lower ball swivel 1590 freely rotates in the x-plane. Connector pin 1596 also interconnects lower ball swivel 1590 to lower frame member 1484 and to a lower tool member 1610 as will be explained hereinafter in greater detail. In this manner, lower ball swivel 1590 is capable of multi-directional, slidable movement within lower casing 1580 . In other words, lower ball swivel 1590 is capable of side-to-side, rotational, or swivel movement in the horizontal x-axis plane as illustrated by previously mentioned directional arrow 1577 (see FIG. 12 ). As described fully hereinbelow, it will be appreciated that ball swivels 1570 / 1590 will rotate in unison and to a like extent due to their interconnection by means of the upper tool member 1600 , the lower tool member 1610 and a pivot pin 1620 (see FIGS. 12 , 15 , 16 and 19 ). Lower tool member 1610 includes a hole 1625 for reasons provided hereinbelow.
Still referring to FIGS. 15 , 16 , 17 , 18 and 19 , to provide hand tool 1450 with the functionality noted hereinabove, hand tool 1450 further includes a tool head assembly, generally referred to as 1630 , for clipping fingernails and toe nails of the user of hand tool 1450 . In other words, tool head assembly 1630 , which is coupled to handle assembly 1460 by means of coupler assembly 1510 , is capable of operating on (i.e., clipping) the fingernails and toe nails (i.e., the work piece) of the user in response to hand manipulation of handle assembly 1460 , as described in detail presently. In this regard, tool head assembly 1630 generally includes the upper tool member or upper jaw 1600 and the lower tool member or lower jaw 1610 . Upper tool member 1600 and lower tool member 1610 are both disposed in the y-axis plane, lower tool member 1610 being oriented opposite to and coincident with upper tool member 1600 . Lower tool member 1610 and upper tool member 1600 are pivotably interconnected by previously mentioned pivot pin 1620 that is sized to be received in previously mentioned hole 1625 , such as by a press fit. Thus, the pivotable interconnection of lower tool member 1610 and upper tool member 1600 allow lower tool member 1610 and upper tool member 1600 to pivot about pivot pin 1620 .
Referring again to FIGS. 15 , 16 , 17 , 18 and 19 , upper tool member 1600 has an inwardly-curved first cutting edge portion 1640 . Similarly, lower tool member 1610 has an inwardly curved second cutting edge portion 1650 . Fingernails and toe nails of the user are clipped or cut when cutting edge portions 1640 / 1650 are brought to bear against each other in the manner described hereinabove.
Illustrative Methods:
An illustrative method associated with an exemplary embodiment for manufacturing the hand tool will now be described.
Referring to FIG. 20 , an illustrative method, generally referred to as 1660 , is provided for manufacturing a hand tool. The method starts at a step 1670 . At a step 1680 , a handle assembly is provided. At a step 1690 , a tool head assembly is coupled to the handle assembly. At a step 1700 , the handle assembly and the tool head assembly are interconnected to at least one heim joint coupler. The method stops at a step 1710 .
Other modifications and implementations will occur to those skilled in the art without departing from the spirit and the scope of the invention as claimed. For example, handle assembly 1010 belonging to the first embodiment hand tool 1000 may be coupled to a hydraulic system that is, in turn, hand actuated. Such a hydraulic system would be coupled to upper handle member 1020 and lower handle 1030 for hydraulically operating upper and lower handle members 1020 / 1030 . As another example, handle assembly 1010 may be coupled to an electric motor system that is, in turn, hand operated by means of a suitable guidance control switch. Such an electric motor system would be coupled to upper handle member 1020 and lower handle member 1030 for electrically operating upper and lower handle members 1020 / 1030 and for articulating the tool head assembly by means of electric motors. These examples can be used for cutting bolts and cables. Accordingly, the description hereinabove is not intended to limit the invention, except as indicated in the following claims.
The claims will be interpreted according to law. However, and notwithstanding the alleged or perceived ease or difficulty of interpreting any claim or portion thereof, under no circumstances may any adjustment or amendment of a claim or any portion thereof during prosecution of the application or applications leading to this patent be interpreted as having forfeited any right to any and all equivalents thereof that do not form a part of the prior art.
All of the features disclosed in this specification may be combined in any combination. Thus, unless expressly stated otherwise, each feature disclosed is only an example of a generic series of equivalent or similar features.
It is to be understood that while the invention has been described in conjunction with the detailed description thereof, the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Thus, from the foregoing, it will be appreciated that, although specific embodiments of the invention have been described herein for the purpose of illustration, various modifications may be made without deviating from the spirit and scope of the invention. Other aspects, advantages, and modifications are within the scope of the following claims and the present invention is not limited except as by the appended claims.
The specific methods and compositions described herein are representative of preferred embodiments and are exemplary and not intended as limitations on the scope of the invention. Other objects, aspects, and embodiments will occur to those skilled in the art upon consideration of this specification, and are encompassed within the spirit of the invention as defined by the scope of the claims. The invention illustratively described herein suitably may be practiced in the absence of any element or elements, or limitation or limitations, which is not specifically disclosed herein as essential. Thus, for example, in each instance herein, in embodiments or examples of the present invention, the terms “comprising”, “including”, “containing”, etc. are to be read expansively and without limitation. The methods and processes illustratively described herein suitably may be practiced in differing orders of steps, and that they are not necessarily restricted to the orders of steps indicated herein or in the claims.
The terms and expressions that have been employed are used as terms of description and not of limitation, and there is no intent in the use of such terms and expressions to exclude any equivalent of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention as claimed. Thus, it will be understood that although the present invention has been specifically disclosed by various embodiments and/or preferred embodiments and optional features, any and all modifications and variations of the concepts herein disclosed that may be resorted to by those skilled in the art are considered to be within the scope of this invention as defined by the appended claims.
The invention has been described broadly and generically herein. Each of the narrower species and subgeneric groupings falling within the generic disclosure also form part of the invention. This includes the generic description of the invention with a proviso or negative limitation removing any subject matter from the genus, regardless of whether or not the excised material is specifically recited herein.
It is also to be understood that as used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural reference unless the context clearly dictates otherwise, the term “X and/or Y” means “X” or “Y” or both “X” and “Y”, and the letter “s” following a noun designates both the plural and singular forms of that noun. In addition, where features or aspects of the invention are described in terms of Markush groups, it is intended and those skilled in the art will recognize, that the invention embraces and is also thereby described in terms of any individual member or subgroup of members of the Markush group.
Other embodiments are within the following claims. The issued patent may not be interpreted to be limited to the specific examples or embodiments or methods specifically and/or expressly disclosed herein. Under no circumstances may the issued patent be interpreted to be limited by any statement made by any Examiner or any other official or employee of the Patent and Trademark Office unless such statement is specifically and without qualification or reservation expressly adopted in a responsive writing by Applicant(s).
Although the invention has been described in terms of exemplary embodiments, it is not limited thereto. Rather, the appended claims should be construed broadly, to include other variants and embodiments of the invention, which may be made by those skilled in the art without departing from the scope and range of equivalents of the invention.
Therefore, provided herein area hand tool and a method of manufacturing and using same.
PARTS LIST
1000 a hand tool
1010 a first embodiment hand held tool mount or handle assembly
1020 an upper handle member
1032 a a proximal end portion
1032 b a distal end portion
1030 a lower handle member
1035 a a proximal end portion
1035 b a distal end portion
1040 an elongate leaf spring
1050 a central straight segment portion
1050 a an upper straight portion
1050 b a lower rounded or curved end portion
1060 a lower handle cutout [SUGGEST IDENTIFY AS 1036 under 1030
1070 a mounting or spring pin
1075 a a direction arrow for upper handle squeezing toward lower handle member
1075 b a direction arrow for lower handle squeezing toward upper handle member
1080 a mounting or linkage bolt
1090 a heim joint coupler assembly
1100 an articulating upper heim joint
1110 an articulating lower heim joint
1120 an upper shank portion
1130 an upper bore or hole
1140 a lower shank portion
1150 a lower bore or hole
1160 an annular upper casing
1165 an upper casing opening
1170 an upper spherical ball swivel
1180 a upper ball hole
1182 a swivel direction arrow for upper ball swivel
1184 a y-axis tilting direction arrow for upper ball swivel
1186 an x-axis tilting direction arrow for upper/lower ball swivel
1190 an annular lower casing
1195 a lower casing opening
1200 a lower spherical ball swivel
1205 a y-axis tilting direction for lower ball swivel
1210 a lower ball hole
1220 a replaceable first embodiment tool head assembly
1230 an upper tool member
1240 a lower tool member
1250 a a lower tool member or first pivoting portion
1250 b an upper tool member or second pivoting portion
1260 an interconnecting pivot pin
1270 an upper jaw or upper blade tool
1280 a first or upper tool elongate front cutting edge portion
1290 a lower jaw or lower blade tool
1300 a second or lower tool elongate front cutting edge portion
1304 a a first or upper tool member upper arm portion
1306 a a first or upper tool member upper arm bore
1304 b a second or upper tool member lower arm portion
1306 b a second or upper tool member lower arm bore
1308 a a third or lower tool member upper arm portion
1308 b a fourth or lower tool member lower arm portion
1309 a a lower tool upper arm bore
1309 b a lower tool lower arm bore
1330 an upper tool screw bolt
1340 a lower tool screw bolt
1350 a detachable second embodiment tool head assembly
1360 an upper jaw
1370 an upper jaw clamping extension 1370
1380 a lower jaw 1380
1390 a lower jaw clamping extension
1400 a detachable third embodiment tool head assembly
1410 an upper jaw 1410
1420 a upper sharpened edge 1420
1430 a lower jaw 1430
1440 a lower sharpened edge 1440
1450 a second embodiment hand tool
1460 a second embodiment hand held tool mount or handle assembly
1470 an upper handle member 1470
1472 a generally smooth, contoured, arcuate-shaped upper shell 1472
1475 an arcuate-shaped upper frame member 1475
1477 a a proximal end portion 1477 a
1477 b a distal end portion 1477 b
1480 a lower handle member 1480
1482 a contoured, arcuate-shaped lower shell 482
1484 an arcuate-shaped lower frame member 1484
1485 a a proximal end portion 1485 a
1485 b a distal end portion 1485 b.
1486 a a proximal end portion 1486 a
1486 b a distal end portion 1486 b
1488 a a proximal end portion 1488 a
1488 b a distal end portion 1488 b
1490 a coiled torsion spring 1490
1500 a mounting or linkage bolt 1500
1510 a tool mount or coupler assembly 1510
1520 an articulating upper heim joint 1520
1530 an articulating lower heim joint 1530
1540 an elongate, externally threaded upper shank portion 1540
1550 an elongate, externally threaded lower shank portion 1550
1560 an annular upper casing 1560
1565 an opening 1565
1570 a spherical upper ball swivel 1570
1575 a hole 1575
1576 a smooth upper connector pin 1576
1577 a directional arrow 1577
1580 an annular lower casing 1580
1585 an opening 1585
1590 a spherical lower ball swivel 1590
1595 a hole 1595
1596 a smooth lower connector pin 159
1610 a lower tool member 1610
1620 a pivot pin 1620
1625 a hole 1625
1630 a tool head assembly 1630
1640 an inwardly-curved first cutting edge portion 1640
1650 an inwardly curved second cutting edge portion 1650 | Hand tool and method of manufacturing and using same. The hand tool includes a tool mount including at least one heim joint that removably receives thereon a tool head assembly. The heim joint and tool head assembly cooperate to provide the hand tool with a multi-directional, variable angle of attack on a work piece in a manner that accommodates aged, arthritic and otherwise handicapped people having a limited range of arm, wrist and hand movement. | 0 |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.